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513 lines
13 KiB
Go

// Package rfm69 RFM69 Implementation in Go
package rfm69
import (
"errors"
"log"
"time"
"github.com/davecheney/gpio"
"github.com/fulr/spidev"
)
const (
spiPath = "/dev/spidev0.0"
)
var frequencies = map[string][]byte{
"433": {0x6C, 0x40, 0x00},
"868": {0xD9, 0x00, 0x00},
"915": {0xE4, 0xC0, 0x00},
}
// OnReceiveHandler is the receive callback
type OnReceiveHandler func(*RXStream)
// Device RFM69 Device
type Device struct {
spiDevice *spidev.SPIDevice
gpio gpio.Pin
mode byte
isRFM69HW bool
powerLevel byte
tx chan *Data
quit chan bool
_invert bool
OnReceive OnReceiveHandler
FreqOffset int
TXBaud int
TXFreq int
TXPower int
RXBaud int
RXFreq int
}
// Global settings
const (
CsmaLimit = -80
MaxDataLen = 66
)
// NewDevice creates a new device
func NewDevice(isRfm69HW bool) (*Device, error) {
pin, err := getPin()
if err != nil {
return nil, err
}
spi, err := spidev.NewSPIDevice(spiPath)
if err != nil {
return nil, err
}
ret := &Device{
spiDevice: spi,
gpio: pin,
isRFM69HW: isRfm69HW,
powerLevel: 31,
_invert: false,
tx: make(chan *Data, 5),
quit: make(chan bool),
FreqOffset: 0,
TXBaud: 1200,
TXFreq: 433e6,
RXBaud: 1200,
RXFreq: 433e6,
}
err = ret.setup()
if err != nil {
return nil, err
}
//go ret.loop()
return ret, nil
}
// Close cleans up
func (r *Device) Close() error {
r.quit <- true
<-r.quit
err := r.gpio.Close()
if err != nil {
return err
}
r.spiDevice.Close()
return err
}
func (r *Device) writeReg(addr, data byte) error {
tx := make([]byte, 2)
tx[0] = addr | 0x80
tx[1] = data
//log.Printf("write %x: %x", addr, data)
_, err := r.spiDevice.Xfer(tx)
if err != nil {
log.Println(err)
}
return err
}
func (r *Device) writeRegDouble(addr byte, data uint16) error {
tx := make([]byte, 3)
tx[0] = addr | 0x80
tx[1] = byte((data >> 8) & 0xFF)
tx[2] = byte(data & 0xFF)
//log.Printf("write %x: %x", addr, data)
_, err := r.spiDevice.Xfer(tx)
if err != nil {
log.Println(err)
}
return err
}
func (r *Device) WriteReg(addr, data byte) error {
return r.writeReg(addr, data)
}
func (r *Device) readReg(addr byte) (byte, error) {
tx := make([]uint8, 2)
tx[0] = addr & 0x7f
tx[1] = 0
rx, err := r.spiDevice.Xfer(tx)
if err != nil {
log.Println(err)
}
return rx[1], err
}
func (r *Device) setup() error {
config := [][]byte{
/* 0x01 */ {REG_OPMODE, RF_OPMODE_SEQUENCER_ON | RF_OPMODE_LISTEN_OFF | RF_OPMODE_STANDBY},
/* 0x02 */ {REG_DATAMODUL, RF_DATAMODUL_DATAMODE_PACKET | RF_DATAMODUL_MODULATIONTYPE_FSK | RF_DATAMODUL_MODULATIONSHAPING_00}, // no shaping
/* 0x03 */ {REG_BITRATEMSB, 0x68},
/* 0x04 */ {REG_BITRATELSB, 0x2B},
/* 0x05 */ {REG_FDEVMSB, 0x00}, // default: 5KHz, (FDEV + BitRate / 2 <= 500KHz)
/* 0x06 */ {REG_FDEVLSB, 0x4a},
/* 0x07 */ {REG_FRFMSB, RF_FRFMSB_868},
/* 0x08 */ {REG_FRFMID, RF_FRFMID_868},
/* 0x09 */ {REG_FRFLSB, RF_FRFLSB_868},
// looks like PA1 and PA2 are not implemented on RFM69W, hence the max output power is 13dBm
// +17dBm and +20dBm are possible on RFM69HW
// +13dBm formula: Pout = -18 + OutputPower (with PA0 or PA1**)
// +17dBm formula: Pout = -14 + OutputPower (with PA1 and PA2)**
// +20dBm formula: Pout = -11 + OutputPower (with PA1 and PA2)** and high power PA settings (section 3.3.7 in datasheet)
///* 0x11 */ { REG_PALEVEL, RF_PALEVEL_PA0_ON | RF_PALEVEL_PA1_OFF | RF_PALEVEL_PA2_OFF | RF_PALEVEL_OUTPUTPOWER_11111},
///* 0x13 */ { REG_OCP, RF_OCP_ON | RF_OCP_TRIM_95 }, // over current protection (default is 95mA)
// RXBW defaults are { REG_RXBW, RF_RXBW_DCCFREQ_010 | RF_RXBW_MANT_24 | RF_RXBW_EXP_5} (RxBw: 10.4KHz)
/* 0x19 */ {REG_RXBW, RF_RXBW_DCCFREQ_010 | RF_RXBW_MANT_16 | RF_RXBW_EXP_2}, // (BitRate < 2 * RxBw)
//for BR-19200: /* 0x19 */ { REG_RXBW, RF_RXBW_DCCFREQ_010 | RF_RXBW_MANT_24 | RF_RXBW_EXP_3 },
/* 0x25 */ {REG_DIOMAPPING1, RF_DIOMAPPING1_DIO0_01}, // DIO0 is the only IRQ we're using
/* 0x26 */ {REG_DIOMAPPING2, RF_DIOMAPPING2_CLKOUT_OFF }, // DIO5 ClkOut disable for power saving
/* 0x28 */ {REG_IRQFLAGS2, RF_IRQFLAGS2_FIFOOVERRUN}, // writing to this bit ensures that the FIFO & status flags are reset
/* 0x29 */ {REG_RSSITHRESH, 220}, // must be set to dBm = (-Sensitivity / 2), default is 0xE4 = 228 so -114dBm
///* 0x2D */ { REG_PREAMBLELSB, RF_PREAMBLESIZE_LSB_VALUE } // default 3 preamble bytes 0xAAAAAA
/* 0x2E */ {REG_SYNCCONFIG, RF_SYNC_ON | RF_SYNC_FIFOFILL_AUTO | RF_SYNC_SIZE_6 | RF_SYNC_TOL_0},
/* 0x2F */ {REG_SYNCVALUE1, 0xAA},
/* 0x30 */ {REG_SYNCVALUE2, 0xAA},
/* 0x30 */ {REG_SYNCVALUE3, 0xAA},
/* 0x30 */ {REG_SYNCVALUE4, 0xAA},
/* 0x30 */ {REG_SYNCVALUE5, 0xAA},
/* 0x30 */ {REG_SYNCVALUE6, 0xAA},
/* 0x37 */ {REG_PACKETCONFIG1, RF_PACKET1_FORMAT_FIXED | RF_PACKET1_DCFREE_OFF | RF_PACKET1_CRC_OFF | RF_PACKET1_CRCAUTOCLEAR_ON | RF_PACKET1_ADRSFILTERING_OFF},
/* 0x38 */ {REG_PAYLOADLENGTH, 0x00}, // in variable length mode: the max frame size, not used in TX, 0: unlimited packet format
///* 0x39 */ { REG_NODEADRS, nodeID }, // turned off because we're not using address filtering
/* 0x3C */ {REG_FIFOTHRESH, RF_FIFOTHRESH_TXSTART_FIFONOTEMPTY | RF_FIFOTHRESH_VALUE}, // TX on FIFO not empty
/* 0x3D */ {REG_PACKETCONFIG2, RF_PACKET2_RXRESTARTDELAY_2BITS | RF_PACKET2_AUTORXRESTART_ON | RF_PACKET2_AES_OFF}, // RXRESTARTDELAY must match transmitter PA ramp-down time (bitrate dependent)
/* 0x2D */ {REG_PREAMBLELSB, 0x00},
//for BR-19200: /* 0x3D */ { REG_PACKETCONFIG2, RF_PACKET2_RXRESTARTDELAY_NONE | RF_PACKET2_AUTORXRESTART_ON | RF_PACKET2_AES_OFF }, // RXRESTARTDELAY must match transmitter PA ramp-down time (bitrate dependent)
/* 0x6F */ {REG_TESTDAGC, RF_DAGC_IMPROVED_LOWBETA0}, // run DAGC continuously in RX mode for Fading Margin Improvement, recommended default for AfcLowBetaOn=0
}
for data, err := r.readReg(REG_SYNCVALUE1); err == nil && data != 0xAA; data, err = r.readReg(REG_SYNCVALUE1) {
err := r.writeReg(REG_SYNCVALUE1, 0xAA)
if err != nil {
return err
}
}
for data, err := r.readReg(REG_SYNCVALUE1); err == nil && data != 0x55; data, err = r.readReg(REG_SYNCVALUE1) {
r.writeReg(REG_SYNCVALUE1, 0x55)
if err != nil {
return err
}
}
for _, c := range config {
err := r.writeReg(c[0], c[1])
if err != nil {
return err
}
}
err := r.Encrypt([]byte{})
if err != nil {
return err
}
err = r.SetInvert(false)
if err != nil {
return err
}
err = r.setHighPower(r.isRFM69HW)
if err != nil {
return err
}
err = r.SetMode(RF_OPMODE_STANDBY)
if err != nil {
return err
}
err = r.waitForMode()
return err
}
func (r *Device) SetInvert(invert bool) error {
r._invert = invert
if (r._invert) {
r.WriteReg(REG_SYNCVALUE1, 0x55)
r.WriteReg(REG_SYNCVALUE2, 0x55)
r.WriteReg(REG_SYNCVALUE3, 0x55)
} else {
r.WriteReg(REG_SYNCVALUE1, 0xAA)
r.WriteReg(REG_SYNCVALUE2, 0xAA)
r.WriteReg(REG_SYNCVALUE3, 0xAA)
}
return nil
}
func (r *Device) waitForMode() error {
errChan := make(chan error)
go func() {
for {
reg, err := r.readReg(REG_IRQFLAGS1)
if err != nil {
errChan <- err
break
}
if reg&RF_IRQFLAGS1_MODEREADY != 0 {
errChan <- nil
break
}
}
}()
time.AfterFunc(5*time.Second, func() {
errChan <- errors.New("timeout")
})
return <-errChan
}
func (r *Device) WaitForMode() error {
return r.waitForMode();
}
// Encrypt sets the encryption key and enables AES encryption
func (r *Device) Encrypt(key []byte) error {
var turnOn byte
if len(key) == 16 {
turnOn = 1
tx := make([]byte, 17)
tx[0] = REG_AESKEY1 | 0x80
copy(tx[1:], key)
if _, err := r.spiDevice.Xfer(tx); err != nil {
return err
}
}
return r.readWriteReg(REG_PACKETCONFIG2, 0xFE, turnOn)
}
func (r *Device) SetBaudrate(rate int) error {
var divider uint16 = (uint16)(32e6 / rate) //0x4F4F
/*switch(rate) {
case 1200:
divider = 0x682B
case 2400:
divider = 0x3415
}*/
return r.writeRegDouble(REG_BITRATEMSB, divider)
}
func (r *Device) SetFrequency(freqHz, offset int) error {
//freqHz = // divide down by FSTEP to get FRF
frf := (int)((float32(freqHz) / float32(61.03515625))) + offset // offset per chip (you may have to calibrate)
if err := r.writeReg(REG_FRFMSB, byte((frf >> 16) & 0xFF)); err != nil {
return err
}
if err := r.writeReg(REG_FRFMID, byte((frf >> 8) & 0xFF)); err != nil {
return err
}
if err := r.writeReg(REG_FRFLSB, byte(frf & 0xFF)); err != nil {
return err
}
return nil
}
// SetMode sets operation mode
func (r *Device) SetMode(newMode byte) error {
if newMode == r.mode {
return nil
}
err := r.readWriteReg(REG_OPMODE, 0xE3, newMode)
if err != nil {
return err
}
if r.isRFM69HW && (newMode == RF_OPMODE_RECEIVER || newMode == RF_OPMODE_TRANSMITTER) {
err := r.setHighPowerRegs(newMode == RF_OPMODE_TRANSMITTER)
if err != nil {
return err
}
}
if r.mode == RF_OPMODE_SLEEP {
err = r.waitForMode()
if err != nil {
return err
}
}
r.mode = newMode
return nil
}
// SetModeAndWait sets the mode and waits for it
func (r *Device) SetModeAndWait(newMode byte) error {
err := r.SetMode(RF_OPMODE_STANDBY)
if err != nil {
return err
}
err = r.waitForMode()
if err != nil {
return err
}
return nil
}
func (r *Device) setHighPower(turnOn bool) error {
r.isRFM69HW = turnOn
ocp := byte(RF_OCP_ON)
if r.isRFM69HW {
ocp = RF_OCP_OFF
}
err := r.writeReg(REG_OCP, ocp)
if err != nil {
return err
}
if r.isRFM69HW {
err = r.readWriteReg(REG_PALEVEL, 0x1F, RF_PALEVEL_PA1_ON|RF_PALEVEL_PA2_ON)
} else {
err = r.readWriteReg(REG_PALEVEL, 0, RF_PALEVEL_PA0_ON|RF_PALEVEL_PA1_OFF|RF_PALEVEL_PA2_OFF|r.powerLevel)
}
return err
}
func (r *Device) setHighPowerRegs(turnOn bool) (err error) {
var (
testPa1 byte = 0x55
testPa2 byte = 0x70
)
if turnOn {
testPa1 = 0x5D
testPa2 = 0x7C
}
err = r.writeReg(REG_TESTPA1, testPa1)
if err != nil {
return
}
err = r.writeReg(REG_TESTPA2, testPa2)
return
}
// SetPowerLevel sets the TX power
func (r *Device) SetPowerLevel(powerLevel byte) error {
r.powerLevel = powerLevel
if r.powerLevel > 31 {
r.powerLevel = 31
}
return r.readWriteReg(REG_PALEVEL, 0xE0, r.powerLevel)
}
func (r *Device) canSend() (bool, error) {
// if signal stronger than -100dBm is detected assume channel activity
if r.mode == RF_OPMODE_RECEIVER {
rssi, err := r.readRSSI(false)
if err != nil {
return false, err
}
if rssi < CsmaLimit {
err = r.SetMode(RF_OPMODE_STANDBY)
return true, err
}
}
return false, nil
}
func (r *Device) readRSSI(forceTrigger bool) (rssi int, err error) {
if forceTrigger {
// RSSI trigger not needed if DAGC is in continuous mode
err = r.writeReg(REG_RSSICONFIG, RF_RSSI_START)
if err != nil {
return
}
for {
data, err := r.readReg(REG_RSSICONFIG)
if err != nil {
return 0, err
}
if data&RF_RSSI_DONE != 0 {
break
}
}
}
data, err := r.readReg(REG_RSSIVALUE)
if err != nil {
return
}
rssi = -int(data) / 2
return
}
func (r *Device) readWriteReg(reg, andMask, orMask byte) error {
regValue, err := r.readReg(reg)
if err != nil {
return err
}
regValue = (regValue & andMask) | orMask
return r.writeReg(reg, regValue)
}
func (r *Device) writeFifo(data []byte) error {
buffersize := len(data)
if buffersize > MaxDataLen {
buffersize = MaxDataLen
}
tx := make([]byte, buffersize+1)
// write to FIFO
tx[0] = REG_FIFO | 0x80
copy(tx[1:], data[:buffersize])
//log.Println("% X\n\n", tx)
_, err := r.spiDevice.Xfer(tx)
return err
}
func (r *Device) WriteFifoData(data []byte) error {
if err := r.writeFifo(data); err != nil {
return err
}
return nil
}
func (r *Device) WriteFifoDataWait() error {
errChan := make(chan error)
go func() {
for {
reg, err := r.readReg(REG_IRQFLAGS2)
if err != nil {
log.Fatal(err)
panic(err)
errChan <- err
break
}
log.Println("% X", reg)
if reg&RF_IRQFLAGS2_FIFONOTEMPTY != 0 {
errChan <- nil
break
}
}
}()
time.AfterFunc(2*time.Second, func() {
errChan <- errors.New("timeout fifowait")
})
return <-errChan
}
func (r *Device) readFifo() (Data, error) {
var err error
data := Data{}
/*data.Rssi, err = r.readRSSI(false)
if err != nil {
return data, err
}*/
tx := new([67]byte)
tx[0] = REG_FIFO & 0x7f
rx, err := r.spiDevice.Xfer(tx[:1])
if err != nil {
return data, err
}
rx, err = r.spiDevice.Xfer(tx[1:])
if err != nil {
return data, err
}
data.Data = rx[1:]
return data, nil
}
func (r *Device) PrepareTX() (error) {
if err := r.SetFrequency(r.TXFreq, r.FreqOffset); err != nil {
return err
}
if err := r.SetBaudrate(r.TXBaud); err != nil {
return err
}
return nil
}
func (r *Device) PrepareRX() (error) {
if err := r.SetFrequency(r.RXFreq, r.FreqOffset); err != nil {
return err
}
if err := r.SetBaudrate(r.RXBaud); err != nil {
return err
}
return nil
}