Updated to travis-ci.com status

.gitignore

@@ -27,3 +27,7 @@
 *.exe
 *.out
 *.app
+
+#Doxygen
+doxygen_sqlite3.db
+html

.travis.yml

@@ -0,0 +1,29 @@
+language: c
+
+addons:
+  apt:
+    packages:
+      - graphviz
+
+# Blacklist
+branches:
+  except:
+    - gh-pages
+
+env:
+  global:
+     - PRETTYNAME="cI2C: Arduino Hardware I2C for AVR (in plain c)"
+     - GH_REPO_NAME: cI2C
+     - GH_REPO_REF: github.com/SMFSW/cI2C.git
+     - DOXYFILE: $TRAVIS_BUILD_DIR/Doxyfile.auto
+
+before_install:
+   - source <(curl -SLs https://raw.githubusercontent.com/SMFSW/travis-ci-arduino/master/install.sh)
+
+script:
+   - build_avr_platforms
+
+# Generate and deploy documentation
+after_success:
+  - source <(curl -SLs  https://raw.githubusercontent.com/SMFSW/travis-ci-arduino/master/library_check.sh)
+  - source <(curl -SLs  https://raw.githubusercontent.com/SMFSW/travis-ci-arduino/master/doxy_gen_and_deploy.sh)

Doxyfile

@@ -1,4 +1,4 @@
-# Doxyfile 1.8.11
+# Doxyfile 1.8.13
 
 # This file describes the settings to be used by the documentation system
 # doxygen (www.doxygen.org) for a project.
@@ -38,7 +38,7 @@ PROJECT_NAME           = "Arduino Hardware I2C for AVR MCUs (plain c)"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 0.5
+PROJECT_NUMBER         = 1.3
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a
@@ -244,7 +244,7 @@ TCL_SUBST              =
 # members will be omitted, etc.
 # The default value is: NO.
 
-OPTIMIZE_OUTPUT_FOR_C  = NO
+OPTIMIZE_OUTPUT_FOR_C  = YES
 
 # Set the OPTIMIZE_OUTPUT_JAVA tag to YES if your project consists of Java or
 # Python sources only. Doxygen will then generate output that is more tailored
@@ -295,6 +295,15 @@ EXTENSION_MAPPING      = ino=C++
 
 MARKDOWN_SUPPORT       = YES
 
+# When the TOC_INCLUDE_HEADINGS tag is set to a non-zero value, all headings up
+# to that level are automatically included in the table of contents, even if
+# they do not have an id attribute.
+# Note: This feature currently applies only to Markdown headings.
+# Minimum value: 0, maximum value: 99, default value: 0.
+# This tag requires that the tag MARKDOWN_SUPPORT is set to YES.
+
+TOC_INCLUDE_HEADINGS   = 0
+
 # When enabled doxygen tries to link words that correspond to documented
 # classes, or namespaces to their corresponding documentation. Such a link can
 # be prevented in individual cases by putting a % sign in front of the word or
@@ -739,7 +748,7 @@ WARN_IF_DOC_ERROR      = YES
 # parameter documentation, but not about the absence of documentation.
 # The default value is: NO.
 
-WARN_NO_PARAMDOC       = NO
+WARN_NO_PARAMDOC       = YES
 
 # If the WARN_AS_ERROR tag is set to YES then doxygen will immediately stop when
 # a warning is encountered.
@@ -761,7 +770,7 @@ WARN_FORMAT            = "$file:$line: $text"
 # messages should be written. If left blank the output is written to standard
 # error (stderr).
 
-WARN_LOGFILE           = 
+WARN_LOGFILE           = workdir/doxy.log
 
 #---------------------------------------------------------------------------
 # Configuration options related to the input files
@@ -773,7 +782,8 @@ WARN_LOGFILE           =
 # spaces. See also FILE_PATTERNS and EXTENSION_MAPPING
 # Note: If this tag is empty the current directory is searched.
 
-INPUT                  = ./
+INPUT                  = ./ \
+                         ./src
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
@@ -795,8 +805,8 @@ INPUT_ENCODING         = UTF-8
 # If left blank the following patterns are tested:*.c, *.cc, *.cxx, *.cpp,
 # *.c++, *.java, *.ii, *.ixx, *.ipp, *.i++, *.inl, *.idl, *.ddl, *.odl, *.h,
 # *.hh, *.hxx, *.hpp, *.h++, *.cs, *.d, *.php, *.php4, *.php5, *.phtml, *.inc,
-# *.m, *.markdown, *.md, *.mm, *.dox, *.py, *.pyw, *.f90, *.f, *.for, *.tcl,
+# *.m, *.markdown, *.md, *.mm, *.dox, *.py, *.pyw, *.f90, *.f95, *.f03, *.f08,
-# *.vhd, *.vhdl, *.ucf, *.qsf, *.as and *.js.
+# *.f, *.for, *.tcl, *.vhd, *.vhdl, *.ucf and *.qsf.
 
 FILE_PATTERNS          = *.c \
                          *.cpp \
@@ -925,7 +935,7 @@ FILTER_SOURCE_PATTERNS =
 # (index.html). This can be useful if you have a project on for instance GitHub
 # and want to reuse the introduction page also for the doxygen output.
 
-USE_MDFILE_AS_MAINPAGE = 
+USE_MDFILE_AS_MAINPAGE = README.md
 
 #---------------------------------------------------------------------------
 # Configuration options related to source browsing
@@ -1719,7 +1729,7 @@ LATEX_EXTRA_FILES      =
 # The default value is: YES.
 # This tag requires that the tag GENERATE_LATEX is set to YES.
 
-PDF_HYPERLINKS         = NO
+PDF_HYPERLINKS         = YES
 
 # If the USE_PDFLATEX tag is set to YES, doxygen will use pdflatex to generate
 # the PDF file directly from the LaTeX files. Set this option to YES, to get a
@@ -2365,6 +2375,11 @@ DIAFILE_DIRS           =
 
 PLANTUML_JAR_PATH      = 
 
+# When using plantuml, the PLANTUML_CFG_FILE tag can be used to specify a
+# configuration file for plantuml.
+
+PLANTUML_CFG_FILE      = 
+
 # When using plantuml, the specified paths are searched for files specified by
 # the !include statement in a plantuml block.
 

README.md

@@ -1,10 +1,12 @@
-# cI2C
+# cI2C [![Build Status](https://travis-ci.com/SMFSW/cI2C.svg?branch=master)](https://travis-ci.com/SMFSW/cI2C)
+
 Arduino Hardware I2C for AVR (plain c)
 
 Hardware I2C library for AVR MCUs (lib intended for I2C protocols development in c, for easier ports to other MCUs)
 
-## Library choice:
+## Library choice
-* cI2C library implements I2C bus for AVR tagets (Uno, Nano, Mega...)
+
+* cI2C library implements I2C bus for AVR targets (Uno, Nano, Mega...)
   * you may prefer this one when:
     * working on AVR targets
     * interrupts are not needed
@@ -16,64 +18,69 @@ Hardware I2C library for AVR MCUs (lib intended for I2C protocols development in
 No refactoring is required when switching between **cI2C** & **WireWrapper** libs;
 Both libs share same Typedefs, Functions & Parameters.
 
-## Notes:
+## Notes
+
 * cI2C is written in plain c (intentionally)
 * cI2C does not use any interrupt (yet, but soon will have to)
 * cI2C is designed to act as bus Master (Slave mode will be considered in future releases)
 * cI2C is set to work on AVR targets only
   * for other targets, you may use **WireWrapper** instead (will be using Wire)
 
-## Usage: 
+## Usage
+
 This library is intended to be able to work with multiple slaves connected on the same I2C bus.
 Thus, the I2C bus and Slaves are defined separately.
 
-* On one hand, I2C bus has to be initialised with appropriate speed:
+* On one hand, I2C bus has to be initialized with appropriate speed:
-  * use I2C_init(speed): speed can be choosen from I2C_SPEED enum for convenience, or passing an integer as parameter
+  * use `I2C_init(speed)`: speed can be chosen from `I2C_SPEED` enum for convenience, or passing an integer as parameter
-* On the other hand, Slave(s) have to be defined and initialised too:
+* On the other hand, Slave(s) have to be defined and initialized too:
-  * use I2C_SLAVE typedef to declare slaves structs
+  * use `I2C_SLAVE` typedef to declare slaves structs
-  * use I2C_slave_init(pSlave, addr, regsize)
+  * use `I2C_slave_init(pSlave, addr, regsize)`
-    * **pSlave** is a pointer to the slave struct to initialise
+    * `pSlave`: pointer to the slave struct to initialize
-    * **addr** is the slave I2C address (don't shift addr, lib takes care of that)
+    * `addr`: slave I2C address (don't shift addr, lib takes care of that)
-    * **regsize** is the width of internal slave registers (to be choosen from I2C_INT_SIZE)
+    * `regsize`: width of internal slave registers (to be chosen from `I2C_INT_SIZE`)
   * in case you need to use custom R/W procedures for a particular slave:
-    * use I2C_slave_set_rw_func(pSlave, pFunc, rw)
+    * use `I2C_slave_set_rw_func(pSlave, pFunc, rw)`
-      * **pSlave** is a pointer to the slave declaration to initialise
+      * `pSlave`: pointer to the slave declaration to initialize
-      * **pFunc** is a pointer to the Read or Write bypass function
+      * `pFunc`: pointer to the Read or Write bypass function
-      * **rw** can be choosen from I2C_RW enum (wr=0, rd=1)
+      * `rw`: can be chosen from `I2C_RW` enum (wr=0, rd=1)
 
 After all inits are done, the lib can basically be used this way:
-* I2C_read(pSlave, regaddr, pData, bytes)
+* `I2C_read(pSlave, regaddr, pData, bytes)`
-  * **pSlave** is a pointer to the slave struct to read from
+  * `pSlave`: pointer to the slave struct to read from
-  * **regaddr** is the start address to read from
+  * `regaddr`: start address to read from
-  * **pData** is a pointer to the place where datas read will be stored
+  * `pData`: pointer to the place where datas read will be stored
-  * **bytes** number of bytes to read from slave
+  * `bytes`: number of bytes to read from slave
-  * returns true if read is ok, false otherwise
+  * returns `true` if read is ok, `false` otherwise
-* I2C_write(pSlave, regaddr, pData, bytes)
+* `I2C_write(pSlave, regaddr, pData, bytes)`
-  * **pSlave** is a pointer to the slave struct to write to
+  * `pSlave`: pointer to the slave struct to write to
-  * **regaddr** is the start address to write to
+  * `regaddr`: start address to write to
-  * **pData** is a pointer to the block of datas to write to slave
+  * `pData`: pointer to the block of datas to write to slave
-  * **bytes** number of bytes to write to slave
+  * `bytes`: number of bytes to write to slave
-  * returns true if write is ok, false otherwise
+  * returns `true` if write is ok, `false` otherwise
+
+## Examples included
 
-## Examples included:
 following examples should work with any I2C EEPROM/FRAM with address 0x50
-(yet function to get Chip ID are device dependant (and will probably only work on FUJITSU devices))
+(yet function to get Chip ID are device dependent (and will probably only work on FUJITSU devices))
-* ci2c_master_write.ino: Write some bytes to FRAM and compare them with what's read afterwards
+* [ci2c_master_write.ino](examples/ci2c_master_write/ci2c_master_write.ino): Write some bytes to FRAM and compare them with what's read afterwards
-* ci2c_master_read.ino: Read some bytes in FRAM
+* [ci2c_master_read.ino](examples/ci2c_master_read/ci2c_master_read.ino): Read some bytes in FRAM
-* ci2c_advanced.ino: Redirecting slave write & read functions (to custom functions following typedef)
+* [ci2c_advanced.ino](examples/ci2c_advanced/ci2c_advanced.ino): Redirecting slave write & read functions (to custom functions following typedef)
 
-Doxygen doc can be generated for the library using doxyfile
+## Documentation
 
-## Links:
+Doxygen doc can be generated using "Doxyfile".
-Feel free to share your thoughts @ xgarmanboziax@gmail.com about:
+
-* issues encountered
+See [generated documentation](https://smfsw.github.io/cI2C/)
-* optimisations
+
-* improvements & new functionalities
+## Release Notes
+
+See [release notes](ReleaseNotes.md)
+
+## See also
 
 **cI2C**
-- https://github.com/SMFSW/cI2C
+* [cI2C github](https://github.com/SMFSW/cI2C) - C implementation of this library
-- https://bitbucket.org/SMFSW/ci2c
 
 **WireWrapper**
-- https://github.com/SMFSW/WireWrapper
+* [WireWrapper github](https://github.com/SMFSW/WireWrapper) - Cpp implementation using Wire Wrapper
-- https://bitbucket.org/SMFSW/wirewrapper

ReleaseNotes.md

@@ -1,20 +1,40 @@
 Arduino Hardware I2C for AVR (plain c)
-2017-2017 SMFSW
+2017-2018 SMFSW
 
 - cI2C is set to work on AVR targets only
 	-> for other targets, you may use WireWrapper instead (will be using Wire)
 	-> cI2C & WireWrapper libs declare same structures & functions as seen from the outside
-		(switch between libs without changing anyhting but the include)
+		(switch between libs without changing anything but the include)
 
 
 Feel free to share your thoughts @ xgarmanboziax@gmail.com about:
 	- issues encountered
-	- optimisations
+	- optimizations
 	- improvements & new functionalities
 
 ------------
 
 ** Actual:
+v1.3	13 May 2018:
+- Delay between retries is now 1ms
+- Adding support for unit tests and doxygen documentation generation with Travis CI
+- Updated README.md
+
+v1.2	30 Nov 2017:
+- No internal address transmission when reading/writing to next internal address (make sure not to r/w last 16 address right just after init, otherwise make a dummy of address 0 just before)
+
+v1.1	29 Nov 2017:
+- Frequency calculation fix (thanks to TonyWilk)
+- Set Frequency higher than Fast Mode (400KHz) will set bus to Fast Mode (frequency is up to 400KHz on AVR)
+- I2C_set_xxx now returns values applied, not bool
+
+v1.0	21 Nov 2017:
+- Added const qualifier for function parameters
+- Return from comm functions if bytes to R/W set to 0
+
+v0.6	12 Jul 2017:
+- compliance with Arduino v1.5+ IDE source located in src subfolder
+
 v0.5	31 Jan 2017:
 - refactored I2C_SPEED enum names for coherence with I2C specifications
 - High Speed mode added in I2C_SPEED enum

ci2c.c

@@ -1,468 +0,0 @@
-/*!\file ci2c.c
-** \author SMFSW
-** \version 0.5
-** \copyright MIT SMFSW (2017)
-** \brief arduino master i2c in plain c code
-**/
-
-// TODO: add interrupt vector / callback for it operations (if not too messy)
-// TODO: consider interrupts at least for RX when slave (and TX when master)
-
-// TODO: change contigous r/w operations so it doesn't send internal address again
-
-// TODO: split functions & headers
-
-
-#include "ci2c.h"
-
-#define START					0x08
-#define REPEATED_START			0x10
-#define MT_SLA_ACK				0x18
-#define MT_SLA_NACK				0x20
-#define MT_DATA_ACK				0x28
-#define MT_DATA_NACK			0x30
-#define MR_SLA_ACK				0x40
-#define MR_SLA_NACK				0x48
-#define MR_DATA_ACK				0x50
-#define MR_DATA_NACK			0x58
-#define LOST_ARBTRTN			0x38
-#define TWI_STATUS				(TWSR & 0xF8)
-
-//#define isSetRegBit(r, b)		((r & (1 << b)) != 0)
-//#define isClrRegBit(r, b)		((r & (1 << b)) == 0)
-
-#define setRegBit(r, b)			r |= (1 << b)				//!< set bit \b b in register \b r
-#define clrRegBit(r, b)			r &= (uint8_t) (~(1 << b))	//!< clear bit \b b in register \b r
-#define invRegBit(r, b)			r ^= (1 << b)				//!< invert bit \b b in register \b r
-
-/*! \struct i2c
- *  \brief static ci2c bus config and control parameters
- */
-static struct {
-	/*! \struct cfg
-	 *  \brief ci2c bus parameters
-	 */
-	struct {
-		I2C_SPEED	speed;			//!< i2c bus speed
-		uint8_t		retries;		//!< i2c message retries when fail
-		uint16_t	timeout;		//!< i2c timeout (ms)
-	} cfg;
-	uint16_t		start_wait;		//!< time start waiting for acknowledge
-	bool			busy;			//!< true if already busy (in case of interrupts implementation)
-} i2c = { { (I2C_SPEED) 0, DEF_CI2C_NB_RETRIES, DEF_CI2C_TIMEOUT }, 0, false };
-
-
-// Needed prototypes
-static bool I2C_wr(I2C_SLAVE * slave, uint16_t reg_addr, uint8_t * data, uint16_t bytes);
-static bool I2C_rd(I2C_SLAVE * slave, uint16_t reg_addr, uint8_t * data, uint16_t bytes);
-
-
-/*! \brief Init an I2C slave structure for cMI2C communication
- *  \param [in] slave - pointer to the I2C slave structure to init
- *  \param [in] sl_addr - I2C slave address
- *  \param [in] reg_sz - internal register map size
- *  \return nothing
- */
-void I2C_slave_init(I2C_SLAVE * slave, uint8_t sl_addr, I2C_INT_SIZE reg_sz)
-{
-	(void) I2C_slave_set_addr(slave, sl_addr);
-	(void) I2C_slave_set_reg_size(slave, reg_sz);
-	I2C_slave_set_rw_func(slave, (ci2c_fct_ptr) I2C_wr, I2C_WRITE);
-	I2C_slave_set_rw_func(slave, (ci2c_fct_ptr) I2C_rd, I2C_READ);
-	slave->reg_addr = 0;
-	slave->status = I2C_OK;
-}
-
-/*! \brief Redirect slave I2C read/write function (if needed for advanced use)
- *  \param [in] slave - pointer to the I2C slave structure to init
- *  \param [in] func - pointer to read/write function to affect
- *  \param [in] rw - 0 = write function, 1 = read function
- *  \return nothing
- */
-void I2C_slave_set_rw_func(I2C_SLAVE * slave, ci2c_fct_ptr func, I2C_RW rw)
-{
-	ci2c_fct_ptr * pfc = (ci2c_fct_ptr*) (rw ? &slave->cfg.rd : &slave->cfg.wr);
-	*pfc = func;
-}
-
-/*! \brief Change I2C slave address
- *  \param [in, out] slave - pointer to the I2C slave structure to init
- *  \param [in] sl_addr - I2C slave address
- *  \return true if new address set (false if address is >7Fh)
- */
-bool I2C_slave_set_addr(I2C_SLAVE * slave, uint8_t sl_addr)
-{
-	if (sl_addr > 0x7F)		{ return false; }
-	slave->cfg.addr = sl_addr;
-	return true;
-}
-
-/*! \brief Change I2C registers map size (for access)
- *  \param [in, out] slave - pointer to the I2C slave structure
- *  \param [in] reg_sz - internal register map size
- *  \return true if new size is correct (false otherwise and set to 16bit by default)
- */
-bool I2C_slave_set_reg_size(I2C_SLAVE * slave, I2C_INT_SIZE reg_sz)
-{
-	slave->cfg.reg_size = reg_sz > I2C_16B_REG ? I2C_16B_REG : reg_sz;
-	return !(reg_sz > I2C_16B_REG);
-}
-
-/*! \brief Set I2C current register address
- *  \attribute inline
- *  \param [in, out] slave - pointer to the I2C slave structure
- *  \param [in] reg_addr - register address
- *  \return nothing
- */
-static inline void __attribute__((__always_inline__)) I2C_slave_set_reg_addr(I2C_SLAVE * slave, uint16_t reg_addr)
-{
-	slave->reg_addr = reg_addr;
-}
-
-
-
-/*! \brief Enable I2c module on arduino board (including pull-ups,
- *         enabling of ACK, and setting clock frequency)
- *  \param [in] speed - I2C bus speed in KHz
- *  \return nothing
- */
-void I2C_init(uint16_t speed)
-{
-	// Set SDA and SCL to ports with pull-ups
-	#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega8__) || defined(__AVR_ATmega328P__)
-		setRegBit(PORTC, 4);
-		setRegBit(PORTC, 5);
-	#else
-		setRegBit(PORTD, 0);
-		setRegBit(PORTD, 1);
-	#endif
-
-	(void) I2C_set_speed(speed);
-}
-
-/*! \brief Disable I2c module on arduino board (releasing pull-ups, and TWI control)
- *  \return nothing
- */
-void I2C_uninit()
-{
-	// Release SDA and SCL ports pull-ups
-	#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega8__) || defined(__AVR_ATmega328P__)
-		clrRegBit(PORTC, 4);
-		clrRegBit(PORTC, 5);
-	#else
-		clrRegBit(PORTD, 0);
-		clrRegBit(PORTD, 1);
-	#endif
-
-	TWCR = 0;
-}
-
-
-/*! \brief I2C bus reset (Release SCL and SDA lines and re-enable module)
- *  \return nothing
- */
-void I2C_reset(void)
-{
-	TWCR = 0;
-	setRegBit(TWCR, TWEA);
-	setRegBit(TWCR, TWEN);
-}
-
-/*! \brief Change I2C frequency
- *  \param [in] speed - I2C speed in kHz (max 1MHz)
- *  \return true if change is successful (false otherwise)
- */
-bool I2C_set_speed(uint16_t speed)
-{
-	i2c.cfg.speed = (I2C_SPEED) ((speed == 0) ? (uint16_t) I2C_STD : ((speed > (uint16_t) I2C_HS) ? (uint16_t) I2C_STD : speed));
-
-	clrRegBit(TWCR, TWEN);	// Ensure i2c module is disabled
-
-	// Set prescaler and clock frequency
-	clrRegBit(TWSR, TWPS0);
-	clrRegBit(TWSR, TWPS1);
-	TWBR = ((F_CPU / (i2c.cfg.speed * 1000)) - 16) / 2;
-
-	I2C_reset();			// re-enable module
-
-	return (i2c.cfg.speed == speed);
-}
-
-/*! \brief Change I2C ack timeout
- *  \param [in] timeout - I2C ack timeout (500 ms max)
- *  \return true if change is successful (false otherwise)
- */
-bool I2C_set_timeout(uint16_t timeout)
-{
-	static const uint16_t max_timeout = 500;
-	i2c.cfg.timeout = (timeout > max_timeout) ? max_timeout : timeout;
-	return (i2c.cfg.timeout == timeout);
-}
-
-/*! \brief Change I2C message retries (in case of failure)
- *  \param [in] retries - I2C number of retries (max of 8)
- *  \return true if change is successful (false otherwise)
- */
-bool I2C_set_retries(uint8_t retries)
-{
-	static const uint16_t max_retries = 8;
-	i2c.cfg.retries = (retries > max_retries) ? max_retries : retries;
-	return (i2c.cfg.retries == retries);
-}
-
-/*! \brief Get I2C busy status
- *  \return true if busy
- */
-bool I2C_is_busy(void)
-{
-	return i2c.busy;
-}
-
-
-/*! \brief This function reads or writes the provided data to/from the address specified.
- *         If anything in the write process is not successful, then it will be repeated
- *         up till 3 more times (default). If still not successful, returns NACK
- *  \param [in, out] slave - pointer to the I2C slave structure to init
- *  \param [in] reg_addr - register address in register map
- *  \param [in] data - pointer to the first byte of a block of data to write
- *  \param [in] bytes - indicates how many bytes of data to write
- *  \param [in] rw - 0 = write, 1 = read operation
- *  \return I2C_STATUS status of write attempt
- */
-static I2C_STATUS I2C_comm(I2C_SLAVE * slave, uint16_t reg_addr, uint8_t * data, uint16_t bytes, I2C_RW rw)
-{
-	uint8_t	retry = i2c.cfg.retries;
-	bool	ack = false;
-	ci2c_fct_ptr fc = (ci2c_fct_ptr) (rw ? slave->cfg.rd : slave->cfg.wr);
-
-	if (I2C_is_busy())	{ return slave->status = I2C_BUSY; }
-	i2c.busy = true;
-
-	ack = fc(slave, reg_addr, data, bytes);
-	while ((!ack) && (retry != 0))	// If com not successful, retry some more times
-	{
-		delay(5);
-		ack = fc(slave, reg_addr, data, bytes);
-		retry--;
-	}
-
-	i2c.busy = false;
-	return slave->status = ack ? I2C_OK : I2C_NACK;
-}
-
-/*! \brief This function writes the provided data to the address specified.
- *  \param [in, out] slave - pointer to the I2C slave structure
- *  \param [in] reg_addr - register address in register map
- *  \param [in] data - pointer to the first byte of a block of data to write
- *  \param [in] bytes - indicates how many bytes of data to write
- *  \return I2C_STATUS status of write attempt
- */
-I2C_STATUS I2C_write(I2C_SLAVE * slave, uint16_t reg_addr, uint8_t * data, uint16_t bytes)
-{
-	return I2C_comm(slave, reg_addr, data, bytes, I2C_WRITE);
-}
-
-/*! \brief This function reads data from the address specified and stores this
- *         data in the area provided by the pointer.
- *  \param [in, out] slave - pointer to the I2C slave structure
- *  \param [in] reg_addr - register address in register map
- *  \param [in, out] data - pointer to the first byte of a block of data to read
- *  \param [in] bytes - indicates how many bytes of data to read
- *  \return I2C_STATUS status of read attempt
- */
-I2C_STATUS I2C_read(I2C_SLAVE * slave, uint16_t reg_addr, uint8_t * data, uint16_t bytes)
-{
-	return I2C_comm(slave, reg_addr, data, bytes, I2C_READ);
-}
-
-
-/*! \brief Start i2c_timeout timer
- *  \attribute inline
- *  \return nothing
- */
-static inline void __attribute__((__always_inline__)) I2C_start_timeout(void)
-{
-	i2c.start_wait = (uint16_t) millis();
-}
-
-/*! \brief Test i2c_timeout
- *  \attribute inline
- *  \return true if i2c_timeout occured (false otherwise)
- */
-static inline uint8_t __attribute__((__always_inline__)) I2C_timeout(void)
-{
-	return (((uint16_t) millis() - i2c.start_wait) >= i2c.cfg.timeout);
-}
-
-/*! \brief Send start condition
- *  \return true if start condition acknowledged (false otherwise)
- */
-bool I2C_start(void)
-{
-	I2C_start_timeout();
-
-	TWCR = (1 << TWINT) | (1 << TWSTA) | (1 << TWEN);
-
-	while (!(TWCR & (1 << TWINT)))
-	{ if (I2C_timeout())	{ I2C_reset(); return false; } }
-
-	if ((TWI_STATUS == START) || (TWI_STATUS == REPEATED_START))	{ return true; }
-	if (TWI_STATUS == LOST_ARBTRTN)									{ I2C_reset(); }
-
-	return false;
-}
-
-/*! \brief Send stop condition
- *  \return true if stop condition acknowledged (false otherwise)
- */
-bool I2C_stop(void)
-{
-	I2C_start_timeout();
-
-	TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);
-
-	while ((TWCR & (1 << TWSTO)))
-	{ if (I2C_timeout())	{ I2C_reset(); return false; } }
-
-	return true;
-}
-
-/*! \brief Send byte on bus
- *  \param [in] dat - data to be sent
- *  \return true if data sent acknowledged (false otherwise)
- */
-bool I2C_wr8(uint8_t dat)
-{
-	TWDR = dat;
-
-	I2C_start_timeout();
-
-	TWCR = (1 << TWINT) | (1 << TWEN);
-
-	while (!(TWCR & (1 << TWINT)))
-	{ if (I2C_timeout())	{ I2C_reset(); return false; } }
-
-	if (TWI_STATUS == MT_DATA_ACK)		{ return true; }
-
-	if (TWI_STATUS == MT_DATA_NACK)		{ I2C_stop(); }
-	else								{ I2C_reset(); }
-
-	return false;
-}
-
-/*! \brief Receive byte from bus
- *  \param [in] ack - true if wait for ack
- *  \return true if data reception acknowledged (false otherwise)
- */
-uint8_t I2C_rd8(bool ack)
-{
-	I2C_start_timeout();
-
-	if (ack)	{ TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWEA); }
-	else		{ TWCR = (1 << TWINT) | (1 << TWEN); }
-
-	while (!(TWCR & (1 << TWINT)))
-	{ if (I2C_timeout())	{ I2C_reset(); return false; } }
-
-	if (TWI_STATUS == LOST_ARBTRTN)		{ I2C_reset(); return false; }
-
-	return ((((TWI_STATUS == MR_DATA_NACK) && (!ack)) || ((TWI_STATUS == MR_DATA_ACK) && (ack))) ? true : false);
-}
-
-/*! \brief Send I2C address
- *  \param [in] slave - pointer to the I2C slave structure
- *  \param [in] rw - read/write transaction
- *  \return true if I2C chip address sent acknowledged (false otherwise)
- */
-bool I2C_sndAddr(I2C_SLAVE * slave, I2C_RW rw)
-{
-	TWDR = (slave->cfg.addr << 1) | rw;
-
-	I2C_start_timeout();
-
-	TWCR = (1 << TWINT) | (1 << TWEN);
-
-	while (!(TWCR & (1 << TWINT)))
-	{ if (I2C_timeout())	{ I2C_reset(); return false; } }
-
-	if ((TWI_STATUS == MT_SLA_ACK) || (TWI_STATUS == MR_SLA_ACK))	{ return true; }
-
-	if ((TWI_STATUS == MT_SLA_NACK) || (TWI_STATUS == MR_SLA_NACK))	{ I2C_stop(); }
-	else															{ I2C_reset(); }
-
-	return false;
-}
-
-
-/*! \brief This procedure calls appropriate functions to perform a proper send transaction on I2C bus.
- *  \param [in, out] slave - pointer to the I2C slave structure
- *  \param [in] reg_addr - register address in register map
- *  \param [in] data - pointer to the first byte of a block of data to write
- *  \param [in] bytes - indicates how many bytes of data to write
- *  \return Boolean indicating success/fail of write attempt
- */
-static bool I2C_wr(I2C_SLAVE * slave, uint16_t reg_addr, uint8_t * data, uint16_t bytes)
-{
-	(void) I2C_slave_set_reg_addr(slave, reg_addr);
-
-	if (I2C_start() == false)									{ return false; }
-	if (I2C_sndAddr(slave, I2C_WRITE) == false)					{ return false; }
-	if (slave->cfg.reg_size)
-	{
-		if (slave->cfg.reg_size >= I2C_16B_REG)	// if size >2, 16bit address is used
-		{
-			if (I2C_wr8((uint8_t) (reg_addr >> 8)) == false)	{ return false; }
-		}
-		if (I2C_wr8((uint8_t) reg_addr) == false)				{ return false; }
-	}
-
-	for (uint16_t cnt = 0; cnt < bytes; cnt++)
-	{
-		if (I2C_wr8(*data++) == false)							{ return false; }
-		slave->reg_addr++;
-	}
-
-	if (I2C_stop() == false)									{ return false; }
-
-	return true;
-}
-
-
-/*! \brief This procedure calls appropriate functions to perform a proper receive transaction on I2C bus.
- *  \param [in, out] slave - pointer to the I2C slave structure
- *  \param [in] reg_addr - register address in register map
- *  \param [in, out] data - pointer to the first byte of a block of data to read
- *  \param [in] bytes - indicates how many bytes of data to read
- *  \return Boolean indicating success/fail of read attempt
- */
-static bool I2C_rd(I2C_SLAVE * slave, uint16_t reg_addr, uint8_t * data, uint16_t bytes)
-{
-	(void) I2C_slave_set_reg_addr(slave, reg_addr);
-
-	if (bytes == 0)	{ bytes = 1; }
-
-	if (slave->cfg.reg_size)	// If start register has to be sent first
-	{
-		if (I2C_start() == false)									{ return false; }
-		if (I2C_sndAddr(slave, I2C_WRITE) == false)					{ return false; }
-		if (slave->cfg.reg_size >= I2C_16B_REG)	// if size >2, 16bit address is used
-		{
-			if (I2C_wr8((uint8_t) (reg_addr >> 8)) == false)		{ return false; }
-		}
-		if (I2C_wr8((uint8_t) reg_addr) == false)					{ return false; }
-	}
-	if (I2C_start() == false)										{ return false; }
-	if (I2C_sndAddr(slave, I2C_READ) == false)						{ return false; }
-
-	for (uint16_t cnt = 0; cnt < bytes; cnt++)
-	{
-		if (I2C_rd8((cnt == (bytes - 1)) ? false : true) == false)	{ return false; }
-		*data++ = TWDR;
-		slave->reg_addr++;
-	}
-
-	if (I2C_stop() == false)										{ return false; }
-
-	return true;
-}
-

ci2c.h

@@ -1,286 +0,0 @@
-/*!\file ci2c.h
-** \author SMFSW
-** \version 0.5
-** \copyright MIT SMFSW (2017)
-** \brief arduino i2c in plain c declarations
-**/
-/****************************************************************/
-#ifndef __CI2C_H__
-	#define __CI2C_H__		"v0.5"
-/****************************************************************/
-
-#if defined(DOXY)
-	// Define gcc __attribute__ as void when Doxygen runs
-	#define __attribute__(a)	//!< GCC attribute (ignored by Doxygen)
-#endif
-
-#if (ARDUINO >= 100)
-	#include <Arduino.h>
-#else
-	#include <WProgram.h>
-#endif
-
-#include <inttypes.h>
-#include <stdbool.h>
-
-
-#ifdef __cplusplus
-extern "C"{
-#endif
-
-#define DEF_CI2C_NB_RETRIES		3		//!< Default cI2C transaction retries
-#define DEF_CI2C_TIMEOUT		100		//!< Default cI2C timeout
-
-
-/*! \enum enI2C_RW
- *  \brief I2C RW bit enumeration
- *  \attribute packed enum
- */
-typedef enum __attribute__((__packed__)) enI2C_RW {
-	I2C_WRITE = 0,	//!< I2C rw bit (write)
-	I2C_READ		//!< I2C rw bit (read)
-} I2C_RW;
-
-
-/*! \enum enI2C_SPEED
- *  \brief I2C bus speed
- *  \attribute packed enum
- */
-typedef enum __attribute__((__packed__)) enI2C_SPEED {
-	I2C_STD = 100,		//!< I2C Standard (100KHz)
-	I2C_FM = 400,		//!< I2C Fast Mode (400KHz)
-	I2C_FMP = 1000,		//!< I2C Fast mode + (1MHz)
-	I2C_HS = 3400		//!< I2C High Speed (3.4MHz)
-} I2C_SPEED;
-
-
-/*! \enum enI2C_STATUS
- *  \brief I2C slave status
- *  \attribute packed enum
- */
-typedef enum __attribute__((__packed__)) enI2C_STATUS {
-	I2C_OK = 0x00,	//!< I2C OK
-	I2C_BUSY,		//!< I2C Bus busy
-	I2C_NACK		//!< I2C Not Acknowledge
-} I2C_STATUS;
-
-/*! \enum enI2C_INT_SIZE
- *  \brief I2C slave internal address registers size
- *  \attribute packed enum
- */
-typedef enum __attribute__((__packed__)) enI2C_INT_SIZE {
-	I2C_NO_REG = 0x00,	//!< Internal address registers not applicable for slave
-	I2C_8B_REG,			//!< Slave internal address registers space is 8bits wide
-	I2C_16B_REG			//!< Slave internal address registers space is 16bits wide
-} I2C_INT_SIZE;
-
-
-typedef bool (*ci2c_fct_ptr) (const void*, uint16_t, uint8_t*, uint16_t);	//!< i2c read/write function pointer typedef
-
-/*! \struct StructI2CSlave
- *  \brief ci2c slave config and control parameters
- *  \attribute packed struct
- */
-typedef struct __attribute__((__packed__)) StructI2CSlave {
-	/*! \struct cfg
-	 *  \brief ci2c slave parameters
-	 */
-	struct {
-		uint8_t			addr;		//!< Slave address
-		I2C_INT_SIZE	reg_size;	//!< Slave internal registers size
-		ci2c_fct_ptr	wr;			//!< Slave write function pointer
-		ci2c_fct_ptr	rd;			//!< Slave read function pointer
-	} cfg;
-	uint16_t			reg_addr;	//!< Internal current register address
-	I2C_STATUS			status;		//!< Status of the last communications
-} I2C_SLAVE;
-
-
-/***************************/
-/*** I2C SLAVE FUNCTIONS ***/
-/***************************/
-
-/*! \brief Init an I2C slave structure for cMI2C communication
- *  \param [in] slave - pointer to the I2C slave structure to init
- *  \param [in] sl_addr - I2C slave address
- *  \param [in] reg_sz - internal register map size
- *  \return nothing
- */
-extern void I2C_slave_init(I2C_SLAVE * slave, uint8_t sl_addr, I2C_INT_SIZE reg_sz);
-
-/*! \brief Redirect slave I2C read/write function (if needed for advanced use)
- *  \param [in] slave - pointer to the I2C slave structure to init
- *  \param [in] func - pointer to read/write function to affect
- *  \param [in] rw - 0 = write function, 1 = read function
- *  \return nothing
- */
-extern void I2C_slave_set_rw_func(I2C_SLAVE * slave, ci2c_fct_ptr func, I2C_RW rw);
-
-/*! \brief Change I2C slave address
- *  \param [in, out] slave - pointer to the I2C slave structure to init
- *  \param [in] sl_addr - I2C slave address
- *  \return true if new address set (false if address is >7Fh)
- */
-extern bool I2C_slave_set_addr(I2C_SLAVE * slave, uint8_t sl_addr);
-
-/*! \brief Change I2C registers map size (for access)
- *  \param [in, out] slave - pointer to the I2C slave structure
- *  \param [in] reg_sz - internal register map size
- *  \return true if new size is correct (false otherwise and set to 16bit by default)
- */
-extern bool I2C_slave_set_reg_size(I2C_SLAVE * slave, I2C_INT_SIZE reg_sz);
-
-/*! \brief Get I2C slave address
- *  \attribute inline
- *  \param [in] slave - pointer to the I2C slave structure
- *  \return I2C slave address
- */
-inline uint8_t __attribute__((__always_inline__)) I2C_slave_get_addr(I2C_SLAVE * slave)
-{
-	return slave->cfg.addr;
-}
-
-/*! \brief Get I2C register map size (for access)
- *  \attribute inline
- *  \param [in] slave - pointer to the I2C slave structure
- *  \return register map using 16bits if true (1Byte otherwise)
- */
-inline bool __attribute__((__always_inline__)) I2C_slave_get_reg_size(I2C_SLAVE * slave)
-{
-	return slave->cfg.reg_size;
-}
-
-/*! \brief Get I2C current register address (addr may passed this way in procedures if contigous accesses)
- *  \attribute inline
- *  \param [in] slave - pointer to the I2C slave structure
- *  \return current register map address
- */
-inline uint16_t __attribute__((__always_inline__)) I2C_slave_get_reg_addr(I2C_SLAVE * slave)
-{
-	return slave->reg_addr;
-}
-
-/*************************/
-/*** I2C BUS FUNCTIONS ***/
-/*************************/
-
-/*! \brief Enable I2c module on arduino board (including pull-ups,
- *         enabling of ACK, and setting clock frequency)
- *  \param [in] speed - I2C bus speed in KHz
- *  \return nothing
- */
-extern void I2C_init(uint16_t speed);
-
-/*! \brief Disable I2c module on arduino board (releasing pull-ups, and TWI control)
- *  \return nothing
- */
-extern void I2C_uninit();
-
-/*! \brief Change I2C frequency
- *  \param [in] speed - I2C bus speed in KHz
- *  \return true if change is successful (false otherwise)
- */
-extern bool I2C_set_speed(uint16_t speed);
-
-/*! \brief Change I2C ack timeout
- *  \param [in] timeout - I2C ack timeout (500 ms max)
- *  \return true if change is successful (false otherwise)
- */
-extern bool I2C_set_timeout(uint16_t timeout);
-
-/*! \brief Change I2C message retries (in case of failure)
- *  \param [in] retries - I2C number of retries (max of 8)
- *  \return true if change is successful (false otherwise)
- */
-extern bool I2C_set_retries(uint8_t retries);
-
-/*! \brief Get I2C busy status
- *  \return true if busy
- */
-extern bool I2C_is_busy(void);
-
-/*! \brief This function writes the provided data to the address specified.
- *  \param [in, out] slave - pointer to the I2C slave structure
- *  \param [in] reg_addr - register address in register map
- *  \param [in] data - pointer to the first byte of a block of data to write
- *  \param [in] bytes - indicates how many bytes of data to write
- *  \return I2C_STATUS status of write attempt
- */
-extern I2C_STATUS I2C_write(I2C_SLAVE * slave, uint16_t reg_addr, uint8_t * data, uint16_t bytes);
-
-/*! \brief This inline is a wrapper to I2C_write in case of contigous operations
- *  \attribute inline
- *  \param [in, out] slave - pointer to the I2C slave structure
- *  \param [in] data - pointer to the first byte of a block of data to write
- *  \param [in] bytes - indicates how many bytes of data to write
- *  \return I2C_STATUS status of write attempt
- */
-inline I2C_STATUS __attribute__((__always_inline__)) I2C_write_next(I2C_SLAVE * slave, uint8_t * data, uint16_t bytes)
-{
-	// TODO: implement read next so that it doesn't have to send start register address again
-	return I2C_write(slave, slave->reg_addr, data, bytes);
-}
-
-/*! \brief This function reads data from the address specified and stores this
- *         data in the area provided by the pointer.
- *  \param [in, out] slave - pointer to the I2C slave structure
- *  \param [in] reg_addr - register address in register map
- *  \param [in, out] data - pointer to the first byte of a block of data to read
- *  \param [in] bytes - indicates how many bytes of data to read
- *  \return I2C_STATUS status of read attempt
- */
-extern I2C_STATUS I2C_read(I2C_SLAVE * slave, uint16_t reg_addr, uint8_t * data, uint16_t bytes);
-
-/*! \brief This inline is a wrapper to I2C_read in case of contigous operations
- *  \attribute inline
- *  \param [in, out] slave - pointer to the I2C slave structure
- *  \param [in] data - pointer to the first byte of a block of data to read
- *  \param [in] bytes - indicates how many bytes of data to read
- *  \return I2C_STATUS status of read attempt
- */
-inline I2C_STATUS __attribute__((__always_inline__)) I2C_read_next(I2C_SLAVE * slave, uint8_t * data, uint16_t bytes)
-{
-	// TODO: implement read next so that it doesn't have to send start register address again
-	return I2C_read(slave, slave->reg_addr, data, bytes);
-}
-
-
-/***********************************/
-/***  cI2C LOW LEVEL FUNCTIONS   ***/
-/*** THAT MAY BE USEFUL FOR DVPT ***/
-/***********************************/
-/*! \brief I2C bus reset (Release SCL and SDA lines and re-enable module)
- *  \return nothing
- */
-extern void I2C_reset(void);
-/*! \brief Send start condition
- *  \return true if start condition acknowledged (false otherwise)
- */
-extern bool I2C_start(void);
-/*! \brief Send stop condition
- *  \return true if stop condition acknowledged (false otherwise)
- */
-extern bool I2C_stop(void);
-/*! \brief Send byte on bus
- *  \param [in] dat - data to be sent
- *  \return true if data sent acknowledged (false otherwise)
- */
-extern bool I2C_wr8(uint8_t dat);
-/*! \brief Receive byte from bus
- *  \param [in] ack - true if wait for ack
- *  \return true if data reception acknowledged (false otherwise)
- */
-extern uint8_t I2C_rd8(bool ack);
-/*! \brief Send I2C address
- *  \param [in] slave - pointer to the I2C slave structure
- *  \param [in] rw - read/write transaction
- *  \return true if I2C chip address sent acknowledged (false otherwise)
- */
-extern bool I2C_sndAddr(I2C_SLAVE * slave, I2C_RW rw);
-
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif

examples/ci2c_advanced/ci2c_advanced.ino

@@ -7,7 +7,7 @@
 	This example code is in the public domain.
 
 	created Jan 12 2017
-	latest mod Jan 31 2017
+	latest mod Nov 30 2017
 	by SMFSW
 */
 
@@ -24,8 +24,8 @@ void setup() {
 	Serial.begin(115200);	// start serial for output
 	I2C_init(I2C_FM);		// init with Fast Mode (400KHz)
 	I2C_slave_init(&FRAM, 0x50, I2C_16B_REG);
-	I2C_slave_set_rw_func(&FRAM, I2C_wr_advanced, I2C_WRITE);
+	I2C_slave_set_rw_func(&FRAM, (ci2c_fct_ptr) I2C_wr_advanced, I2C_WRITE);
-	I2C_slave_set_rw_func(&FRAM, I2C_rd_advanced, I2C_READ);
+	I2C_slave_set_rw_func(&FRAM, (ci2c_fct_ptr) I2C_rd_advanced, I2C_READ);
 
 	I2C_get_chip_id(&FRAM, &str[0]);
 
@@ -62,14 +62,16 @@ void loop() {
  *  \param [in] bytes - indicates how many bytes of data to write
  *  \return Boolean indicating success/fail of write attempt
  */
-bool I2C_wr_advanced(I2C_SLAVE * slave, uint16_t reg_addr, uint8_t * data, uint16_t bytes)
+bool I2C_wr_advanced(I2C_SLAVE * slave, const uint16_t reg_addr, uint8_t * data, const uint16_t bytes)
 {
-	slave->reg_addr = reg_addr;
+	if (bytes == 0)												{ return false; }
 
 	if (I2C_start() == false)									{ return false; }
 	if (I2C_sndAddr(slave, I2C_WRITE) == false)					{ return false; }
-	if (slave->cfg.reg_size)
+	if ((slave->cfg.reg_size) && (reg_addr != slave->reg_addr))	// Don't send address if writing next
 	{
+		slave->reg_addr = reg_addr;
+
 		if (slave->cfg.reg_size >= I2C_16B_REG)	// if size >2, 16bit address is used
 		{
 			if (I2C_wr8((uint8_t) (reg_addr >> 8)) == false)	{ return false; }
@@ -96,14 +98,14 @@ bool I2C_wr_advanced(I2C_SLAVE * slave, uint16_t reg_addr, uint8_t * data, uint1
  *  \param [in] bytes - indicates how many bytes of data to read
  *  \return Boolean indicating success/fail of read attempt
  */
-bool I2C_rd_advanced(I2C_SLAVE * slave, uint16_t reg_addr, uint8_t * data, uint16_t bytes)
+bool I2C_rd_advanced(I2C_SLAVE * slave, const uint16_t reg_addr, uint8_t * data, const uint16_t bytes)
 {
+	if (bytes == 0)													{ return false; }
+
+	if ((slave->cfg.reg_size) && (reg_addr != slave->reg_addr))	// Don't send address if reading next
+	{
 		slave->reg_addr = reg_addr;
 
-	if (bytes == 0)	{ bytes = 1; }
-
-	if (slave->cfg.reg_size)
-	{
 		if (I2C_start() == false)									{ return false; }
 		if (I2C_sndAddr(slave, I2C_WRITE) == false)					{ return false; }
 		if (slave->cfg.reg_size >= I2C_16B_REG)	// if size >2, 16bit address is used

library.properties

@@ -1,7 +1,7 @@
 name=cI2C
-version=0.5
+version=1.3
-author=SMFSW
+author=SMFSW <xgarmanboziax@gmail.com>
-maintainer=SMFSW
+maintainer=SMFSW <xgarmanboziax@gmail.com>
 sentence=Arduino Hardware I2C for AVR (in plain c)
 paragraph=Hardware I2C library for AVR MCUs (lib intended for I2C protocols development in c, for easier ports to other MCUs)
 category=Communication

src/ci2c.c

@@ -0,0 +1,453 @@
+/*!\file ci2c.c
+** \author SMFSW
+** \copyright MIT SMFSW (2017-2018)
+** \brief arduino master i2c in plain c code
+** \warning Don't access (r/w) last 16b internal address byte alone right after init, this would lead to hazardous result (in such case, make a dummy read of addr 0 before)
+**/
+
+// TODO: add interrupt vector / callback for it operations (if not too messy)
+// TODO: consider interrupts at least for RX when slave (and TX when master)
+
+#include "ci2c.h"
+
+#define START					0x08
+#define REPEATED_START			0x10
+#define MT_SLA_ACK				0x18
+#define MT_SLA_NACK				0x20
+#define MT_DATA_ACK				0x28
+#define MT_DATA_NACK			0x30
+#define MR_SLA_ACK				0x40
+#define MR_SLA_NACK				0x48
+#define MR_DATA_ACK				0x50
+#define MR_DATA_NACK			0x58
+#define LOST_ARBTRTN			0x38
+#define TWI_STATUS				(TWSR & 0xF8)
+
+//#define isSetRegBit(r, b)		((r & (1 << b)) != 0)
+//#define isClrRegBit(r, b)		((r & (1 << b)) == 0)
+
+#define setRegBit(r, b)			r |= (1 << b)				//!< set bit \b b in register \b r
+#define clrRegBit(r, b)			r &= (uint8_t) (~(1 << b))	//!< clear bit \b b in register \b r
+#define invRegBit(r, b)			r ^= (1 << b)				//!< invert bit \b b in register \b r
+
+/*!\struct i2c
+** \brief static ci2c bus config and control parameters
+**/
+static struct {
+	/*!\struct cfg
+	** \brief ci2c bus parameters
+	**/
+	struct {
+		I2C_SPEED	speed;			//!< i2c bus speed
+		uint8_t		retries;		//!< i2c message retries when fail
+		uint16_t	timeout;		//!< i2c timeout (ms)
+	} cfg;
+	uint16_t		start_wait;		//!< time start waiting for acknowledge
+	bool			busy;			//!< true if already busy (in case of interrupts implementation)
+} i2c = { { (I2C_SPEED) 0, DEF_CI2C_NB_RETRIES, DEF_CI2C_TIMEOUT }, 0, false };
+
+
+// Needed prototypes
+static bool I2C_wr(I2C_SLAVE * slave, const uint16_t reg_addr, uint8_t * data, const uint16_t bytes);
+static bool I2C_rd(I2C_SLAVE * slave, const uint16_t reg_addr, uint8_t * data, const uint16_t bytes);
+
+
+/*!\brief Init an I2C slave structure for cMI2C communication
+** \param [in] slave - pointer to the I2C slave structure to init
+** \param [in] sl_addr - I2C slave address
+** \param [in] reg_sz - internal register map size
+** \return nothing
+**/
+void I2C_slave_init(I2C_SLAVE * slave, const uint8_t sl_addr, const I2C_INT_SIZE reg_sz)
+{
+	(void) I2C_slave_set_addr(slave, sl_addr);
+	(void) I2C_slave_set_reg_size(slave, reg_sz);
+	I2C_slave_set_rw_func(slave, (ci2c_fct_ptr) I2C_wr, I2C_WRITE);
+	I2C_slave_set_rw_func(slave, (ci2c_fct_ptr) I2C_rd, I2C_READ);
+	slave->reg_addr = (uint16_t) -1;	// To be sure to send address on first access (warning: unless last 16b byte address is accessed alone)
+	slave->status = I2C_OK;
+}
+
+/*!\brief Redirect slave I2C read/write function (if needed for advanced use)
+** \param [in] slave - pointer to the I2C slave structure to init
+** \param [in] func - pointer to read/write function to affect
+** \param [in] rw - 0 = write function, 1 = read function
+** \return nothing
+**/
+void I2C_slave_set_rw_func(I2C_SLAVE * slave, const ci2c_fct_ptr func, const I2C_RW rw)
+{
+	ci2c_fct_ptr * pfc = (ci2c_fct_ptr*) (rw ? &slave->cfg.rd : &slave->cfg.wr);
+	*pfc = func;
+}
+
+/*!\brief Change I2C slave address
+** \param [in, out] slave - pointer to the I2C slave structure to init
+** \param [in] sl_addr - I2C slave address
+** \return true if new address set (false if address is >7Fh)
+**/
+bool I2C_slave_set_addr(I2C_SLAVE * slave, const uint8_t sl_addr)
+{
+	if (sl_addr > 0x7F)		{ return false; }
+	slave->cfg.addr = sl_addr;
+	return true;
+}
+
+/*!\brief Change I2C registers map size (for access)
+** \param [in, out] slave - pointer to the I2C slave structure
+** \param [in] reg_sz - internal register map size
+** \return true if new size is correct (false otherwise and set to 16bit by default)
+**/
+bool I2C_slave_set_reg_size(I2C_SLAVE * slave, const I2C_INT_SIZE reg_sz)
+{
+	slave->cfg.reg_size = reg_sz > I2C_16B_REG ? I2C_16B_REG : reg_sz;
+	return !(reg_sz > I2C_16B_REG);
+}
+
+/*!\brief Set I2C current register address
+** \attribute inline
+** \param [in, out] slave - pointer to the I2C slave structure
+** \param [in] reg_addr - register address
+** \return nothing
+**/
+static inline void __attribute__((__always_inline__)) I2C_slave_set_reg_addr(I2C_SLAVE * slave, const uint16_t reg_addr) {
+	slave->reg_addr = reg_addr; }
+
+
+
+/*!\brief Enable I2c module on arduino board (including pull-ups,
+ *        enabling of ACK, and setting clock frequency)
+** \param [in] speed - I2C bus speed in KHz
+** \return nothing
+**/
+void I2C_init(const uint16_t speed)
+{
+	// Set SDA and SCL to ports with pull-ups
+	#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega8__) || defined(__AVR_ATmega328P__)
+		setRegBit(PORTC, 4);
+		setRegBit(PORTC, 5);
+	#else
+		setRegBit(PORTD, 0);
+		setRegBit(PORTD, 1);
+	#endif
+
+	(void) I2C_set_speed(speed);
+}
+
+/*!\brief Disable I2c module on arduino board (releasing pull-ups, and TWI control)
+** \return nothing
+**/
+void I2C_uninit()
+{
+	// Release SDA and SCL ports pull-ups
+	#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega8__) || defined(__AVR_ATmega328P__)
+		clrRegBit(PORTC, 4);
+		clrRegBit(PORTC, 5);
+	#else
+		clrRegBit(PORTD, 0);
+		clrRegBit(PORTD, 1);
+	#endif
+
+	TWCR = 0;
+}
+
+
+/*!\brief I2C bus reset (Release SCL and SDA lines and re-enable module)
+** \return nothing
+**/
+void I2C_reset(void)
+{
+	TWCR = 0;
+	setRegBit(TWCR, TWEA);
+	setRegBit(TWCR, TWEN);
+}
+
+/*!\brief Change I2C frequency
+** \param [in] speed - I2C speed in KHz (max 400KHz on avr)
+** \return Configured bus speed
+**/
+uint16_t I2C_set_speed(const uint16_t speed)
+{
+	i2c.cfg.speed = (I2C_SPEED) ((speed == 0) ? (uint16_t) I2C_STD : ((speed > (uint16_t) I2C_FM) ? (uint16_t) I2C_FM : speed));
+
+	clrRegBit(TWCR, TWEN);	// Ensure i2c module is disabled
+
+	// Set prescaler and clock frequency
+	clrRegBit(TWSR, TWPS0);
+	clrRegBit(TWSR, TWPS1);
+	TWBR = (((F_CPU / 1000) / i2c.cfg.speed) - 16) / 2;
+
+	I2C_reset();			// re-enable module
+
+	return i2c.cfg.speed;
+}
+
+/*!\brief Change I2C ack timeout
+** \param [in] timeout - I2C ack timeout (500 ms max)
+** \return Configured timeout
+**/
+uint16_t I2C_set_timeout(const uint16_t timeout)
+{
+	static const uint16_t max_timeout = 500;
+	i2c.cfg.timeout = (timeout > max_timeout) ? max_timeout : timeout;
+	return i2c.cfg.timeout;
+}
+
+/*!\brief Change I2C message retries (in case of failure)
+** \param [in] retries - I2C number of retries (max of 8)
+** \return Configured number of retries
+**/
+uint8_t I2C_set_retries(const uint8_t retries)
+{
+	static const uint16_t max_retries = 8;
+	i2c.cfg.retries = (retries > max_retries) ? max_retries : retries;
+	return i2c.cfg.retries;
+}
+
+/*!\brief Get I2C busy status
+** \return true if busy
+**/
+bool I2C_is_busy(void) {
+	return i2c.busy; }
+
+
+/*!\brief This function reads or writes the provided data to/from the address specified.
+ *        If anything in the write process is not successful, then it will be repeated
+ *        up till 3 more times (default). If still not successful, returns NACK
+** \param [in, out] slave - pointer to the I2C slave structure to init
+** \param [in] reg_addr - register address in register map
+** \param [in] data - pointer to the first byte of a block of data to write
+** \param [in] bytes - indicates how many bytes of data to write
+** \param [in] rw - 0 = write, 1 = read operation
+** \return I2C_STATUS status of write attempt
+**/
+static I2C_STATUS I2C_comm(I2C_SLAVE * slave, const uint16_t reg_addr, uint8_t * data, const uint16_t bytes, const I2C_RW rw)
+{
+	uint8_t			retry = i2c.cfg.retries;
+	bool			ack = false;
+	ci2c_fct_ptr	fc = (ci2c_fct_ptr) (rw ? slave->cfg.rd : slave->cfg.wr);
+
+	if (I2C_is_busy())	{ return slave->status = I2C_BUSY; }
+	i2c.busy = true;
+
+	ack = fc(slave, reg_addr, data, bytes);
+	while ((!ack) && (retry != 0))	// If com not successful, retry some more times
+	{
+		delay(1);
+		ack = fc(slave, reg_addr, data, bytes);
+		retry--;
+	}
+
+	i2c.busy = false;
+	return slave->status = ack ? I2C_OK : I2C_NACK;
+}
+
+/*!\brief This function writes the provided data to the address specified.
+** \param [in, out] slave - pointer to the I2C slave structure
+** \param [in] reg_addr - register address in register map
+** \param [in] data - pointer to the first byte of a block of data to write
+** \param [in] bytes - indicates how many bytes of data to write
+** \return I2C_STATUS status of write attempt
+**/
+I2C_STATUS I2C_write(I2C_SLAVE * slave, const uint16_t reg_addr, uint8_t * data, const uint16_t bytes) {
+	return I2C_comm(slave, reg_addr, data, bytes, I2C_WRITE); }
+
+/*!\brief This function reads data from the address specified and stores this
+ *        data in the area provided by the pointer.
+** \param [in, out] slave - pointer to the I2C slave structure
+** \param [in] reg_addr - register address in register map
+** \param [in, out] data - pointer to the first byte of a block of data to read
+** \param [in] bytes - indicates how many bytes of data to read
+** \return I2C_STATUS status of read attempt
+**/
+I2C_STATUS I2C_read(I2C_SLAVE * slave, const uint16_t reg_addr, uint8_t * data, const uint16_t bytes) {
+	return I2C_comm(slave, reg_addr, data, bytes, I2C_READ); }
+
+
+/*!\brief Start i2c_timeout timer
+** \attribute inline
+** \return nothing
+**/
+static inline void __attribute__((__always_inline__)) I2C_start_timeout(void) {
+	i2c.start_wait = (uint16_t) millis(); }
+
+/*!\brief Test i2c_timeout
+** \attribute inline
+** \return true if i2c_timeout occured (false otherwise)
+**/
+static inline uint8_t __attribute__((__always_inline__)) I2C_timeout(void) {
+	return (((uint16_t) millis() - i2c.start_wait) >= i2c.cfg.timeout); }
+
+/*!\brief Send start condition
+** \return true if start condition acknowledged (false otherwise)
+**/
+bool I2C_start(void)
+{
+	I2C_start_timeout();
+
+	TWCR = (1 << TWINT) | (1 << TWSTA) | (1 << TWEN);
+
+	while (!(TWCR & (1 << TWINT)))
+	{ if (I2C_timeout())	{ I2C_reset(); return false; } }
+
+	if ((TWI_STATUS == START) || (TWI_STATUS == REPEATED_START))	{ return true; }
+	if (TWI_STATUS == LOST_ARBTRTN)									{ I2C_reset(); }
+
+	return false;
+}
+
+/*!\brief Send stop condition
+** \return true if stop condition acknowledged (false otherwise)
+**/
+bool I2C_stop(void)
+{
+	I2C_start_timeout();
+
+	TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO);
+
+	while ((TWCR & (1 << TWSTO)))
+	{ if (I2C_timeout())	{ I2C_reset(); return false; } }
+
+	return true;
+}
+
+/*!\brief Send byte on bus
+** \param [in] dat - data to be sent
+** \return true if data sent acknowledged (false otherwise)
+**/
+bool I2C_wr8(const uint8_t dat)
+{
+	TWDR = dat;
+
+	I2C_start_timeout();
+
+	TWCR = (1 << TWINT) | (1 << TWEN);
+
+	while (!(TWCR & (1 << TWINT)))
+	{ if (I2C_timeout())	{ I2C_reset(); return false; } }
+
+	if (TWI_STATUS == MT_DATA_ACK)		{ return true; }
+
+	if (TWI_STATUS == MT_DATA_NACK)		{ I2C_stop(); }
+	else								{ I2C_reset(); }
+
+	return false;
+}
+
+/*!\brief Receive byte from bus
+** \param [in] ack - true if wait for ack
+** \return true if data reception acknowledged (false otherwise)
+**/
+uint8_t I2C_rd8(const bool ack)
+{
+	I2C_start_timeout();
+
+	if (ack)	{ TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWEA); }
+	else		{ TWCR = (1 << TWINT) | (1 << TWEN); }
+
+	while (!(TWCR & (1 << TWINT)))
+	{ if (I2C_timeout())	{ I2C_reset(); return false; } }
+
+	if (TWI_STATUS == LOST_ARBTRTN)		{ I2C_reset(); return false; }
+
+	return ((((TWI_STATUS == MR_DATA_NACK) && (!ack)) || ((TWI_STATUS == MR_DATA_ACK) && (ack))) ? true : false);
+}
+
+/*!\brief Send I2C address
+** \param [in] slave - pointer to the I2C slave structure
+** \param [in] rw - read/write transaction
+** \return true if I2C chip address sent acknowledged (false otherwise)
+**/
+bool I2C_sndAddr(I2C_SLAVE * slave, const I2C_RW rw)
+{
+	TWDR = (slave->cfg.addr << 1) | rw;
+
+	I2C_start_timeout();
+
+	TWCR = (1 << TWINT) | (1 << TWEN);
+
+	while (!(TWCR & (1 << TWINT)))
+	{ if (I2C_timeout())	{ I2C_reset(); return false; } }
+
+	if ((TWI_STATUS == MT_SLA_ACK) || (TWI_STATUS == MR_SLA_ACK))	{ return true; }
+
+	if ((TWI_STATUS == MT_SLA_NACK) || (TWI_STATUS == MR_SLA_NACK))	{ I2C_stop(); }
+	else															{ I2C_reset(); }
+
+	return false;
+}
+
+
+/*!\brief This procedure calls appropriate functions to perform a proper send transaction on I2C bus.
+** \param [in, out] slave - pointer to the I2C slave structure
+** \param [in] reg_addr - register address in register map
+** \param [in] data - pointer to the first byte of a block of data to write
+** \param [in] bytes - indicates how many bytes of data to write
+** \return Boolean indicating success/fail of write attempt
+**/
+static bool I2C_wr(I2C_SLAVE * slave, const uint16_t reg_addr, uint8_t * data, const uint16_t bytes)
+{
+	if (bytes == 0)												{ return false; }
+
+	if (I2C_start() == false)									{ return false; }
+	if (I2C_sndAddr(slave, I2C_WRITE) == false)					{ return false; }
+	if ((slave->cfg.reg_size) && (reg_addr != slave->reg_addr))	// Don't send address if writing next
+	{
+		(void) I2C_slave_set_reg_addr(slave, reg_addr);
+
+		if (slave->cfg.reg_size >= I2C_16B_REG)	// if size >2, 16bit address is used
+		{
+			if (I2C_wr8((uint8_t) (reg_addr >> 8)) == false)	{ return false; }
+		}
+		if (I2C_wr8((uint8_t) reg_addr) == false)				{ return false; }
+	}
+
+	for (uint16_t cnt = 0; cnt < bytes; cnt++)
+	{
+		if (I2C_wr8(*data++) == false)							{ return false; }
+		slave->reg_addr++;
+	}
+
+	if (I2C_stop() == false)									{ return false; }
+
+	return true;
+}
+
+
+/*!\brief This procedure calls appropriate functions to perform a proper receive transaction on I2C bus.
+** \param [in, out] slave - pointer to the I2C slave structure
+** \param [in] reg_addr - register address in register map
+** \param [in, out] data - pointer to the first byte of a block of data to read
+** \param [in] bytes - indicates how many bytes of data to read
+** \return Boolean indicating success/fail of read attempt
+**/
+static bool I2C_rd(I2C_SLAVE * slave, const uint16_t reg_addr, uint8_t * data, const uint16_t bytes)
+{
+	if (bytes == 0)													{ return false; }
+
+	if ((slave->cfg.reg_size) && (reg_addr != slave->reg_addr))	// Don't send address if reading next
+	{
+		(void) I2C_slave_set_reg_addr(slave, reg_addr);
+
+		if (I2C_start() == false)									{ return false; }
+		if (I2C_sndAddr(slave, I2C_WRITE) == false)					{ return false; }
+		if (slave->cfg.reg_size >= I2C_16B_REG)	// if size >2, 16bit address is used
+		{
+			if (I2C_wr8((uint8_t) (reg_addr >> 8)) == false)		{ return false; }
+		}
+		if (I2C_wr8((uint8_t) reg_addr) == false)					{ return false; }
+	}
+	if (I2C_start() == false)										{ return false; }
+	if (I2C_sndAddr(slave, I2C_READ) == false)						{ return false; }
+
+	for (uint16_t cnt = 0; cnt < bytes; cnt++)
+	{
+		if (I2C_rd8((cnt == (bytes - 1)) ? false : true) == false)	{ return false; }
+		*data++ = TWDR;
+		slave->reg_addr++;
+	}
+
+	if (I2C_stop() == false)										{ return false; }
+
+	return true;
+}
+

src/ci2c.h

@@ -0,0 +1,281 @@
+/*!\file ci2c.h
+** \author SMFSW
+** \copyright MIT SMFSW (2017-2018)
+** \brief arduino i2c in plain c declarations
+** \warning Don't access (r/w) last 16b internal address byte alone right after init, this would lead to hazardous result (in such case, make a dummy read of addr 0 before)
+**/
+/****************************************************************/
+#ifndef __CI2C_H__
+	#define __CI2C_H__
+/****************************************************************/
+
+#if defined(DOXY)
+	// Define gcc __attribute__ as void when Doxygen runs
+	#define __attribute__(a)	//!< GCC attribute (ignored by Doxygen)
+#endif
+
+#if (ARDUINO >= 100)
+	#include <Arduino.h>
+#else
+	#include <WProgram.h>
+#endif
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define DEF_CI2C_NB_RETRIES		3		//!< Default cI2C transaction retries
+#define DEF_CI2C_TIMEOUT		100		//!< Default cI2C timeout
+
+
+/*!\enum enI2C_RW
+** \brief I2C RW bit enumeration
+** \attribute packed enum
+**/
+typedef enum __attribute__((__packed__)) enI2C_RW {
+	I2C_WRITE = 0,	//!< I2C rw bit (write)
+	I2C_READ		//!< I2C rw bit (read)
+} I2C_RW;
+
+
+/*!\enum enI2C_SPEED
+** \brief I2C bus speed
+** \attribute packed enum
+**/
+typedef enum __attribute__((__packed__)) enI2C_SPEED {
+	I2C_STD = 100,		//!< I2C Standard (100KHz)
+	I2C_FM = 400,		//!< I2C Fast Mode (400KHz)
+	I2C_FMP = 1000,		//!< I2C Fast mode + (1MHz): will set speed to Fast Mode (up to 400KHz on avr)
+	I2C_HS = 3400		//!< I2C High Speed (3.4MHz): will set speed to Fast Mode (up to 400KHz on avr)
+} I2C_SPEED;
+
+
+/*!\enum enI2C_STATUS
+** \brief I2C slave status
+** \attribute packed enum
+**/
+typedef enum __attribute__((__packed__)) enI2C_STATUS {
+	I2C_OK = 0x00,	//!< I2C OK
+	I2C_BUSY,		//!< I2C Bus busy
+	I2C_NACK		//!< I2C Not Acknowledge
+} I2C_STATUS;
+
+/*!\enum enI2C_INT_SIZE
+** \brief I2C slave internal address registers size
+** \attribute packed enum
+**/
+typedef enum __attribute__((__packed__)) enI2C_INT_SIZE {
+	I2C_NO_REG = 0x00,	//!< Internal address registers not applicable for slave
+	I2C_8B_REG,			//!< Slave internal address registers space is 8bits wide
+	I2C_16B_REG			//!< Slave internal address registers space is 16bits wide
+} I2C_INT_SIZE;
+
+
+typedef bool (*ci2c_fct_ptr) (void*, const uint16_t, uint8_t*, const uint16_t);	//!< i2c read/write function pointer typedef
+
+
+/*!\struct StructI2CSlave
+** \brief ci2c slave config and control parameters
+** \attribute packed struct
+**/
+typedef struct __attribute__((__packed__)) StructI2CSlave {
+	/*!\struct cfg
+	** \brief ci2c slave parameters
+	**/
+	struct {
+		uint8_t			addr;		//!< Slave address
+		I2C_INT_SIZE	reg_size;	//!< Slave internal registers size
+		ci2c_fct_ptr	wr;			//!< Slave write function pointer
+		ci2c_fct_ptr	rd;			//!< Slave read function pointer
+	} cfg;
+	uint16_t			reg_addr;	//!< Internal current register address
+	I2C_STATUS			status;		//!< Status of the last communications
+} I2C_SLAVE;
+
+
+/***************************/
+/*** I2C SLAVE FUNCTIONS ***/
+/***************************/
+
+/*!\brief Init an I2C slave structure for cMI2C communication
+** \param [in] slave - pointer to the I2C slave structure to init
+** \param [in] sl_addr - I2C slave address
+** \param [in] reg_sz - internal register map size
+** \return nothing
+**/
+void I2C_slave_init(I2C_SLAVE * slave, const uint8_t sl_addr, const I2C_INT_SIZE reg_sz);
+
+/*!\brief Redirect slave I2C read/write function (if needed for advanced use)
+** \param [in] slave - pointer to the I2C slave structure to init
+** \param [in] func - pointer to read/write function to affect
+** \param [in] rw - 0 = write function, 1 = read function
+** \return nothing
+**/
+void I2C_slave_set_rw_func(I2C_SLAVE * slave, const ci2c_fct_ptr func, const I2C_RW rw);
+
+/*!\brief Change I2C slave address
+** \param [in, out] slave - pointer to the I2C slave structure to init
+** \param [in] sl_addr - I2C slave address
+** \return true if new address set (false if address is >7Fh)
+**/
+bool I2C_slave_set_addr(I2C_SLAVE * slave, const uint8_t sl_addr);
+
+/*!\brief Change I2C registers map size (for access)
+** \param [in, out] slave - pointer to the I2C slave structure
+** \param [in] reg_sz - internal register map size
+** \return true if new size is correct (false otherwise and set to 16bit by default)
+**/
+bool I2C_slave_set_reg_size(I2C_SLAVE * slave, const I2C_INT_SIZE reg_sz);
+
+/*!\brief Get I2C slave address
+** \attribute inline
+** \param [in] slave - pointer to the I2C slave structure
+** \return I2C slave address
+**/
+inline uint8_t __attribute__((__always_inline__)) I2C_slave_get_addr(const I2C_SLAVE * slave) {
+	return slave->cfg.addr; }
+
+/*!\brief Get I2C register map size (for access)
+** \attribute inline
+** \param [in] slave - pointer to the I2C slave structure
+** \return register map using 16bits if true (1Byte otherwise)
+**/
+inline bool __attribute__((__always_inline__)) I2C_slave_get_reg_size(const I2C_SLAVE * slave) {
+	return slave->cfg.reg_size; }
+
+/*!\brief Get I2C current register address (addr may passed this way in procedures if contigous accesses)
+** \attribute inline
+** \param [in] slave - pointer to the I2C slave structure
+** \return current register map address
+**/
+inline uint16_t __attribute__((__always_inline__)) I2C_slave_get_reg_addr(const I2C_SLAVE * slave) {
+	return slave->reg_addr; }
+
+
+/*************************/
+/*** I2C BUS FUNCTIONS ***/
+/*************************/
+
+/*!\brief Enable I2c module on arduino board (including pull-ups,
+ *        enabling of ACK, and setting clock frequency)
+** \param [in] speed - I2C bus speed in KHz
+** \return nothing
+**/
+void I2C_init(const uint16_t speed);
+
+/*!\brief Disable I2c module on arduino board (releasing pull-ups, and TWI control)
+** \return nothing
+**/
+void I2C_uninit();
+
+/*!\brief Change I2C frequency
+** \param [in] speed - I2C bus speed in KHz (max 400KHz on AVR)
+** \return Configured bus speed
+**/
+uint16_t I2C_set_speed(const uint16_t speed);
+
+/*!\brief Change I2C ack timeout
+** \param [in] timeout - I2C ack timeout (500 ms max)
+** \return Configured timeout
+**/
+uint16_t I2C_set_timeout(const uint16_t timeout);
+
+/*!\brief Change I2C message retries (in case of failure)
+** \param [in] retries - I2C number of retries (max of 8)
+** \return Configured number of retries
+**/
+uint8_t I2C_set_retries(const uint8_t retries);
+
+/*!\brief Get I2C busy status
+** \return true if busy
+**/
+bool I2C_is_busy(void);
+
+/*!\brief This function writes the provided data to the address specified.
+** \param [in, out] slave - pointer to the I2C slave structure
+** \param [in] reg_addr - register address in register map
+** \param [in] data - pointer to the first byte of a block of data to write
+** \param [in] bytes - indicates how many bytes of data to write
+** \return I2C_STATUS status of write attempt
+**/
+I2C_STATUS I2C_write(I2C_SLAVE * slave, const uint16_t reg_addr, uint8_t * data, const uint16_t bytes);
+
+/*!\brief This inline is a wrapper to I2C_write in case of contigous operations
+** \attribute inline
+** \param [in, out] slave - pointer to the I2C slave structure
+** \param [in] data - pointer to the first byte of a block of data to write
+** \param [in] bytes - indicates how many bytes of data to write
+** \return I2C_STATUS status of write attempt
+**/
+inline I2C_STATUS __attribute__((__always_inline__)) I2C_write_next(I2C_SLAVE * slave, uint8_t * data, const uint16_t bytes) {
+	return I2C_write(slave, slave->reg_addr, data, bytes); }
+
+/*!\brief This function reads data from the address specified and stores this
+ *        data in the area provided by the pointer.
+** \param [in, out] slave - pointer to the I2C slave structure
+** \param [in] reg_addr - register address in register map
+** \param [in, out] data - pointer to the first byte of a block of data to read
+** \param [in] bytes - indicates how many bytes of data to read
+** \return I2C_STATUS status of read attempt
+**/
+I2C_STATUS I2C_read(I2C_SLAVE * slave, const uint16_t reg_addr, uint8_t * data, const uint16_t bytes);
+
+/*!\brief This inline is a wrapper to I2C_read in case of contigous operations
+** \attribute inline
+** \param [in, out] slave - pointer to the I2C slave structure
+** \param [in] data - pointer to the first byte of a block of data to read
+** \param [in] bytes - indicates how many bytes of data to read
+** \return I2C_STATUS status of read attempt
+**/
+inline I2C_STATUS __attribute__((__always_inline__)) I2C_read_next(I2C_SLAVE * slave, uint8_t * data, const uint16_t bytes) {
+	return I2C_read(slave, slave->reg_addr, data, bytes); }
+
+
+/***********************************/
+/***  cI2C LOW LEVEL FUNCTIONS   ***/
+/*** THAT MAY BE USEFUL FOR DVPT ***/
+/***********************************/
+/*!\brief I2C bus reset (Release SCL and SDA lines and re-enable module)
+** \return nothing
+**/
+void I2C_reset(void);
+
+/*!\brief Send start condition
+** \return true if start condition acknowledged (false otherwise)
+**/
+bool I2C_start(void);
+
+/*!\brief Send stop condition
+** \return true if stop condition acknowledged (false otherwise)
+**/
+bool I2C_stop(void);
+
+/*!\brief Send byte on bus
+** \param [in] dat - data to be sent
+** \return true if data sent acknowledged (false otherwise)
+**/
+bool I2C_wr8(const uint8_t dat);
+
+/*!\brief Receive byte from bus
+** \param [in] ack - true if wait for ack
+** \return true if data reception acknowledged (false otherwise)
+**/
+uint8_t I2C_rd8(const bool ack);
+
+/*!\brief Send I2C address
+** \param [in] slave - pointer to the I2C slave structure
+** \param [in] rw - read/write transaction
+** \return true if I2C chip address sent acknowledged (false otherwise)
+**/
+bool I2C_sndAddr(I2C_SLAVE * slave, const I2C_RW rw);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif