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