188 lines
4.4 KiB
Go
188 lines
4.4 KiB
Go
package main
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import (
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"errors"
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"fmt"
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"github.com/op/go-logging"
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"golang.org/x/exp/io/i2c"
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"math"
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"time"
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)
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const (
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MODE1 byte = 0x00
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MODE2 byte = 0x01
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PRESCALE byte = 0xFE
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LED0_ON_L byte = 0x06
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LED0_ON_H byte = 0x07
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LED0_OFF_L byte = 0x08
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LED0_OFF_H byte = 0x09
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ALL_LED_ON_L byte = 0xFA
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ALL_LED_ON_H byte = 0xFB
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ALL_LED_OFF_L byte = 0xFC
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ALL_LED_OFF_H byte = 0xFD
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OUTDRV byte = 0x04
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SLEEP byte = 0x10
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WORD byte = 0xFF
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)
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type PCA9685 struct {
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i2cBus *i2c.Device
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name string
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initiated bool
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minPulse uint16
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maxPulse uint16
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log *logging.Logger
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frequency float32
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}
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type Pwm struct {
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pca *PCA9685
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pin int
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lastValue float32
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}
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func createPCA9685(i2cDevice *i2c.Device, name string, minPulse uint16, maxPulse uint16, log *logging.Logger) *PCA9685 {
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log.Info(fmt.Sprintf("Creating a new PCA9685 device. Alias: %v", name))
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return &PCA9685{
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i2cBus: i2cDevice,
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name: name,
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initiated: false,
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minPulse: minPulse,
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maxPulse: maxPulse,
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log: log,
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frequency: 1000.0,
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}
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}
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func (p *PCA9685) NewPwm(pin int) *Pwm {
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p.log.Info(fmt.Sprintf("Creating a new Pwm controler at pin %v from %v", pin, p.name))
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return &Pwm{
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pca: p,
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pin: pin,
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lastValue: 0.0,
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}
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}
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func (p *PCA9685) Init() {
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if p.initiated {
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p.log.Warning(fmt.Sprintf("Device \"%v\" already initiated!", p.name))
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} else {
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p.log.Info(fmt.Sprintf("Initiating \"%v\" PCA9685 device", p.name))
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p.setAllPwm(0, 0)
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p.i2cBus.WriteReg(MODE2, []byte{OUTDRV})
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time.Sleep(5 * time.Millisecond)
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var mode1 byte
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err := p.i2cBus.ReadReg(MODE1, []byte{mode1})
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if err != nil {
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p.log.Error("Can't read!")
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return
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}
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mode1 &= WORD
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mode1 = mode1 & ^SLEEP
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p.i2cBus.WriteReg(MODE1, []byte{mode1 & 0xFF})
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time.Sleep(5 * time.Millisecond)
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p.setPwmFreq(p.frequency)
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p.initiated = true
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}
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}
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func (p *PCA9685) SwitchOn(pwm []int) error {
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if !p.initiated {
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return errors.New(fmt.Sprintf("Device \"%v\"is not initiated!", p.name))
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}
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for i := 0; i < len(pwm); i++ {
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p.log.Info(fmt.Sprintf("Swiching on pwm #%v", pwm[i]))
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p.setPwm(pwm[i], p.minPulse, p.maxPulse)
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}
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return nil
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}
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func (p *PCA9685) SwitchOff(pwm []int) error {
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if !p.initiated {
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return errors.New(fmt.Sprintf("Device \"%v\"is not initiated!", p.name))
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}
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for i := 0; i < len(pwm); i++ {
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p.log.Info(fmt.Sprintf("Swiching off pwm #%v", pwm[i]))
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p.setPwm(pwm[i], 0, p.minPulse)
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}
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return nil
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}
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func (p *PCA9685) setPwmFreq(freqHz float32) {
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var prescaleValue float32 = 25000000.0 // 25MHz
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prescaleValue /= 4096.0
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prescaleValue /= freqHz
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prescaleValue -= 1.0
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p.log.Debug(fmt.Sprintf("Setting PWM frequency to %v Hz", freqHz))
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p.log.Debug(fmt.Sprintf("Esimated pre-scale: %v", prescaleValue))
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prescale := int(math.Floor(float64(prescaleValue + 0.5)))
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p.log.Debug(fmt.Sprintf("Final pre.scale: %v", prescale))
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var oldMode byte
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err := p.i2cBus.ReadReg(MODE1, []byte{oldMode})
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if err != nil {
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p.log.Error("Can't read!")
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}
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oldMode &= WORD
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newMode := (oldMode & 0x7F) | 0x10
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p.i2cBus.WriteReg(MODE1, []byte{newMode & WORD})
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p.i2cBus.WriteReg(PRESCALE, []byte{byte(prescale) & WORD})
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p.i2cBus.WriteReg(MODE1, []byte{oldMode & WORD})
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time.Sleep(5 * time.Millisecond)
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p.i2cBus.WriteReg(MODE1, []byte{oldMode&WORD | 0x80})
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}
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func (p *PCA9685) setAllPwm(on uint16, off uint16) {
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onB := byte(on)
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offB := byte(off)
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p.i2cBus.WriteReg(ALL_LED_ON_L, []byte{onB & WORD})
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p.i2cBus.WriteReg(ALL_LED_ON_H, []byte{onB & WORD})
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p.i2cBus.WriteReg(ALL_LED_OFF_L, []byte{offB & WORD})
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p.i2cBus.WriteReg(ALL_LED_OFF_H, []byte{offB & WORD})
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}
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func (p *PCA9685) setPwm(pwm int, on uint16, off uint16) {
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p.i2cBus.WriteReg(LED0_ON_H+byte(4)*byte(pwm), []byte{byte(on >> 8)})
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p.i2cBus.WriteReg(LED0_ON_L+byte(4)*byte(pwm), []byte{byte(on & 0x00FF)})
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p.i2cBus.WriteReg(LED0_OFF_H+byte(4)*byte(pwm), []byte{byte(off >> 8)})
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p.i2cBus.WriteReg(LED0_OFF_L+byte(4)*byte(pwm), []byte{byte(off & 0x00FF)})
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}
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func (pwm *Pwm) setPercentage(percentage float32) error {
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if percentage < 0.0 || percentage > 100.0 {
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return errors.New(fmt.Sprintf("Percentage must be between 0.0 and 100.0. Got %v.", percentage))
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}
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pwm.pca.setPwm(pwm.pin, 0, uint16((percentage/100)*float32(pwm.pca.maxPulse)))
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pwm.pca.log.Info(fmt.Sprintf("Setting pwm #%v to %v%% (%v) at \"%v\" device.", pwm.pin, percentage, uint16((percentage/100)*float32(pwm.pca.maxPulse)), pwm.pca.name))
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return nil
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}
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