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mirror of https://github.com/kidoman/embd synced 2024-12-22 12:50:19 +01:00

-Removed low resolution mode from bh1750fvi package

-Fixed bugs with i2c commands used for data acquisition
This commit is contained in:
Kunal Powar 2013-12-20 00:43:40 +05:30
parent 2ac61dad95
commit 898041c4ce
2 changed files with 72 additions and 76 deletions

View File

@ -14,8 +14,7 @@ func main() {
log.Panic(err)
}
lightingSensor := bh1750Fvi.New("H", bus)
lightingSensor := bh1750Fvi.New(bh1750Fvi.High, bus)
defer lightingSensor.Close()
for {
@ -23,7 +22,8 @@ func main() {
if err != nil {
log.Panic(err)
}
log.Printf("Lighting is %v", lighting, "lx")
log.Printf("Lighting is %v lx", lighting)
time.Sleep(500 * time.Millisecond)
}
}

View File

@ -1,4 +1,4 @@
// Package BH1750FVI allows interfacing with the BH1750FVI ambient light sensor through I2C protocol
// Package BH1750FVI allows interfacing with the BH1750FVI ambient light sensor through I2C protocol.
package bh1750Fvi
import (
@ -9,28 +9,34 @@ import (
"github.com/kid0m4n/go-rpi/i2c"
)
//accuracy = sensorValue/actualValue] (min = 0.96, typ = 1.2, max = 1.44
const (
measurementAcuuracy = 1.2 // [accuracy = sensorValue/actualValue] (min = 0.96, typ = 1.2, max = 1.44)
High = "H"
High2 = "H2"
highResolutionReadAddress = 0x23
highResolutionOperationCode = 0x10
measurementAcuuracy = 1.2
defReadReg = 0x00
lowResolutionReadAddress = 0x5c
lowResolutionOperationCode = 0x23
sensorI2cAddr = 0x23
highResolutionMode2ReadAddress = 0x23
highResolutionMode2OperationCode = 0x11
highResOpCode = 0x10
highResMode2OpCode = 0x11
pollDelay = 150
)
// A BH1750VI interface implements access to the sensor.
type BH1750VI interface {
Start() error
// Run starts continuous sensor data acquisition loop.
Run() error
// Lighting returns the ambient lighting in lx.
Lighting() (lighting float64, err error)
// Close.
Close()
// SetPollDelay sets the delay between run of data acquisition loop.
SetPollDelay(delay int)
}
@ -41,105 +47,89 @@ type bh1750vi struct {
lightingReadings chan float64
quit chan bool
ready bool
readRegisterAddress byte
i2cAddr byte
operationCode byte
continuousMode bool
poll int
}
var Default = New("H", i2c.Default)
// Default instance for BH1750FVI sensor
var Default = New(High, i2c.Default)
// Supports three modes:
// "H" -> High resolution mode (1lx), takes 120ms (recommended).
// "H2" -> High resolution mode 2 (0.5lx), takes 120ms (only use for low light).
// New creates a new BH1750FVI interface according to the mode passed.
func New(mode string, bus i2c.Bus) BH1750VI {
/*
Supports three modes:
"L" -> Low resolution mode (4lx), takes 16ms
"H" -> High resolution mode (1lx), takes 120ms (recommended)
"H2" -> High resolution mode 2 (0.5lx), takes 120ms (only use for low light)
*/
switch mode {
case "L":
return &bh1750vi{bus: bus, readRegisterAddress: lowResolutionReadAddress, operationCode: lowResolutionOperationCode, continuousMode: false}
case "H":
return &bh1750vi{bus: bus, readRegisterAddress: highResolutionReadAddress, operationCode: highResolutionOperationCode, continuousMode: true}
case "H2":
return &bh1750vi{bus: bus, readRegisterAddress: highResolutionMode2ReadAddress, operationCode: highResolutionMode2OperationCode, continuousMode: true}
case High:
return &bh1750vi{bus: bus, i2cAddr: sensorI2cAddr, operationCode: highResOpCode, mu: new(sync.RWMutex)}
case High2:
return &bh1750vi{bus: bus, i2cAddr: sensorI2cAddr, operationCode: highResMode2OpCode, mu: new(sync.RWMutex)}
default:
return &bh1750vi{bus: bus, readRegisterAddress: highResolutionReadAddress, operationCode: highResolutionOperationCode, continuousMode: true}
return &bh1750vi{bus: bus, i2cAddr: sensorI2cAddr, operationCode: highResOpCode, mu: new(sync.RWMutex)}
}
}
func (sensor *bh1750vi) setup() (err error) {
sensor.mu.Lock()
if sensor.ready && sensor.continuousMode { //for Low resolution mode sensor has to be initialized for every read.
sensor.mu.Unlock()
return
// NewHighMode returns a BH1750FVI inteface on high resolution mode (1lx resolution)
func NewHighMode(bus i2c.Bus) BH1750VI {
return New(High, bus)
}
defer sensor.mu.Unlock()
// NewHighMode returns a BH1750FVI inteface on high resolution mode2 (0.5lx resolution)
func NewHigh2Mode(bus i2c.Bus) BH1750VI {
return New(High2, bus)
}
err = sensor.bus.WriteByte(sensor.readRegisterAddress, sensor.operationCode)
func (d *bh1750vi) measureLighting() (lighting float64, err error) {
err = d.bus.WriteByte(d.i2cAddr, d.operationCode)
if err != nil {
log.Print("bh1750vi: Failed to initialize sensor")
return
}
time.Sleep(180 * time.Millisecond)
sensor.ready = true
var sensorReading int
if sensorReading, err = d.bus.ReadInt(d.i2cAddr, defReadReg); err != nil {
return
}
func (sensor *bh1750vi) measureLighting() (lighting float64, err error) {
if err = sensor.setup(); err != nil {
return
}
sensorData := make([]byte, 2)
if err = sensor.bus.ReadFromReg(sensor.readRegisterAddress, sensor.operationCode, sensorData); err != nil {
return
}
sensorReading := (int16(sensorData[0] << 8)) | (int16(sensorData[1]))
lighting = float64(sensorReading) / measurementAcuuracy
return
}
func (sensor *bh1750vi) Lighting() (lighting float64, err error) {
// Lighting returns the ambient lighting in lx.
func (d *bh1750vi) Lighting() (lighting float64, err error) {
select {
case lighting = <-sensor.lightingReadings:
case lighting = <-d.lightingReadings:
return
default:
return sensor.measureLighting()
return d.measureLighting()
}
}
func (sensor *bh1750vi) Start() (err error) {
// Run starts continuous sensor data acquisition loop.
func (d *bh1750vi) Run() (err error) {
go func() {
sensor.quit = make(chan bool)
d.quit = make(chan bool)
timer := time.Tick(time.Duration(sensor.poll) * time.Millisecond)
timer := time.Tick(time.Duration(d.poll) * time.Millisecond)
var lighting float64
for {
select {
case sensor.lightingReadings <- lighting:
case d.lightingReadings <- lighting:
case <-timer:
if l, err := sensor.measureLighting(); err == nil {
if l, err := d.measureLighting(); err == nil {
lighting = l
}
if err == nil && sensor.lightingReadings == nil {
sensor.lightingReadings = make(chan float64)
if err == nil && d.lightingReadings == nil {
d.lightingReadings = make(chan float64)
}
case <-sensor.quit:
sensor.lightingReadings = nil
case <-d.quit:
d.lightingReadings = nil
return
}
}
@ -147,29 +137,35 @@ func (sensor *bh1750vi) Start() (err error) {
return
}
func (sensor *bh1750vi) Close() {
if sensor.quit != nil {
sensor.quit <- true
// Close.
func (d *bh1750vi) Close() {
if d.quit != nil {
d.quit <- true
}
return
}
func (sensor *bh1750vi) SetPollDelay(delay int) {
sensor.poll = delay
// SetPollDelay sets the delay between run of data acquisition loop.
func (d *bh1750vi) SetPollDelay(delay int) {
d.poll = delay
}
// SetPollDelay sets the delay between run of data acquisition loop.
func SetPollDelay(delay int) {
Default.SetPollDelay(delay)
}
// Lighting returns the ambient lighting in lx.
func Lighting() (lighting float64, err error) {
return Default.Lighting()
}
func Start() (err error) {
return Default.Start()
// Run starts continuous sensor data acquisition loop.
func Run() (err error) {
return Default.Run()
}
// Close.
func Close() {
Default.Close()
}