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Update firmata package for new gpio interface
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@zankich
zankich committed Nov 19, 2014
1 parent 66c861d commit 3efaa46
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Showing 4 changed files with 230 additions and 103 deletions.
125 changes: 78 additions & 47 deletions platforms/firmata/firmata.go
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,7 @@ package firmata

import (
"bytes"
"errors"
"fmt"
"io"
"math"
Expand Down Expand Up @@ -103,20 +104,26 @@ func newBoard(sp io.ReadWriteCloser) *board {

// connect starts connection to board.
// Queries report version until connected
func (b *board) connect() {
func (b *board) connect() (err error) {
if b.connected == false {
b.reset()
if err = b.reset(); err != nil {
return err
}
b.initBoard()

for {
b.queryReportVersion()
if err = b.queryReportVersion(); err != nil {
return err
}
<-time.After(b.initTimeInterval)
b.readAndProcess()
if err = b.readAndProcess(); err != nil {
return err
}
if b.connected == true {
break
}
}
}
return
}

// initBoard initializes board by listening for "firware_query", "capability_query"
Expand All @@ -138,23 +145,27 @@ func (b *board) initBoard() {
}

// readAndProcess reads from serial port and parses data.
func (b *board) readAndProcess() {
b.process(b.read())
func (b *board) readAndProcess() error {
buf, err := b.read()
if err != nil {
return err
}
return b.process(buf)
}

// reset writes system reset bytes.
func (b *board) reset() {
b.write([]byte{systemReset})
func (b *board) reset() error {
return b.write([]byte{systemReset})
}

// setPinMode writes pin mode bytes for specified pin.
func (b *board) setPinMode(pin byte, mode byte) {
func (b *board) setPinMode(pin byte, mode byte) error {
b.pins[pin].mode = mode
b.write([]byte{pinMode, pin, mode})
return b.write([]byte{pinMode, pin, mode})
}

// digitalWrite is used to send a digital value to a specified pin.
func (b *board) digitalWrite(pin byte, value byte) {
func (b *board) digitalWrite(pin byte, value byte) error {
port := byte(math.Floor(float64(pin) / 8))
portValue := byte(0)

Expand All @@ -165,13 +176,13 @@ func (b *board) digitalWrite(pin byte, value byte) {
portValue = portValue | (1 << i)
}
}
b.write([]byte{digitalMessage | port, portValue & 0x7F, (portValue >> 7) & 0x7F})
return b.write([]byte{digitalMessage | port, portValue & 0x7F, (portValue >> 7) & 0x7F})
}

// analogWrite writes value to specified pin
func (b *board) analogWrite(pin byte, value byte) {
func (b *board) analogWrite(pin byte, value byte) error {
b.pins[pin].value = int(value)
b.write([]byte{analogMessage | pin, value & 0x7F, (value >> 7) & 0x7F})
return b.write([]byte{analogMessage | pin, value & 0x7F, (value >> 7) & 0x7F})
}

// version returns board version following MAYOR.minor convention.
Expand All @@ -180,73 +191,74 @@ func (b *board) version() string {
}

// queryFirmware writes bytes to query firmware from board.
func (b *board) queryFirmware() {
b.write([]byte{startSysex, firmwareQuery, endSysex})
func (b *board) queryFirmware() error {
return b.write([]byte{startSysex, firmwareQuery, endSysex})
}

// queryPinState writes bytes to retrieve pin state
func (b *board) queryPinState(pin byte) {
b.write([]byte{startSysex, pinStateQuery, pin, endSysex})
func (b *board) queryPinState(pin byte) error {
return b.write([]byte{startSysex, pinStateQuery, pin, endSysex})
}

// queryReportVersion sends query for report version
func (b *board) queryReportVersion() {
b.write([]byte{reportVersion})
func (b *board) queryReportVersion() error {
return b.write([]byte{reportVersion})
}

// queryCapabilities is used to retrieve board capabilities.
func (b *board) queryCapabilities() {
b.write([]byte{startSysex, capabilityQuery, endSysex})
func (b *board) queryCapabilities() error {
return b.write([]byte{startSysex, capabilityQuery, endSysex})
}

// queryAnalogMapping returns analog mapping for board.
func (b *board) queryAnalogMapping() {
b.write([]byte{startSysex, analogMappingQuery, endSysex})
func (b *board) queryAnalogMapping() error {
return b.write([]byte{startSysex, analogMappingQuery, endSysex})
}

// togglePinReporting is used to change pin reporting mode.
func (b *board) togglePinReporting(pin byte, state byte, mode byte) {
b.write([]byte{mode | pin, state})
func (b *board) togglePinReporting(pin byte, state byte, mode byte) error {
return b.write([]byte{mode | pin, state})
}

// i2cReadRequest reads from slaveAddress.
func (b *board) i2cReadRequest(slaveAddress byte, numBytes uint) {
b.write([]byte{startSysex, i2CRequest, slaveAddress, (i2CModeRead << 3),
func (b *board) i2cReadRequest(slaveAddress byte, numBytes uint) error {
return b.write([]byte{startSysex, i2CRequest, slaveAddress, (i2CModeRead << 3),
byte(numBytes & 0x7F), byte(((numBytes >> 7) & 0x7F)), endSysex})
}

// i2cWriteRequest writes to slaveAddress.
func (b *board) i2cWriteRequest(slaveAddress byte, data []byte) {
func (b *board) i2cWriteRequest(slaveAddress byte, data []byte) error {
ret := []byte{startSysex, i2CRequest, slaveAddress, (i2CModeWrite << 3)}
for _, val := range data {
ret = append(ret, byte(val&0x7F))
ret = append(ret, byte((val>>7)&0x7F))
}
ret = append(ret, endSysex)
b.write(ret)
return b.write(ret)
}

// i2xConfig returns i2c configuration.
func (b *board) i2cConfig(data []byte) {
func (b *board) i2cConfig(data []byte) error {
ret := []byte{startSysex, i2CConfig}
for _, val := range data {
ret = append(ret, byte(val&0xFF))
ret = append(ret, byte((val>>8)&0xFF))
}
ret = append(ret, endSysex)
b.write(ret)
return b.write(ret)
}

// write is used to send commands to serial port
func (b *board) write(commands []byte) {
b.serial.Write(commands[:])
func (b *board) write(commands []byte) (err error) {
_, err = b.serial.Write(commands[:])
return
}

// read returns buffer reading from serial port (1024 bytes)
func (b *board) read() []byte {
buf := make([]byte, 1024)
b.serial.Read(buf)
return buf
func (b *board) read() (buf []byte, err error) {
buf = make([]byte, 1024)
_, err = b.serial.Read(buf)
return
}

// process uses incoming data and executes actions depending on what is received.
Expand All @@ -255,23 +267,34 @@ func (b *board) read() []byte {
// And the following responses: capability, analog mapping, pin state,
// i2c, firmwareQuery, string data.
// If neither of those messages is received, then data is treated as "bad_byte"
func (b *board) process(data []byte) {
func (b *board) process(data []byte) (err error) {
buf := bytes.NewBuffer(data)
for {
messageType, err := buf.ReadByte()
if err != nil {
// we ran out of bytes so we break out of the process loop
break
}
switch {
case reportVersion == messageType:
b.majorVersion, _ = buf.ReadByte()
b.minorVersion, _ = buf.ReadByte()
if b.majorVersion, err = buf.ReadByte(); err != nil {
return err
}
if b.minorVersion, err = buf.ReadByte(); err != nil {
return err
}
gobot.Publish(b.events["report_version"], b.version())
case analogMessageRangeStart <= messageType &&
analogMessageRangeEnd >= messageType:

leastSignificantByte, _ := buf.ReadByte()
mostSignificantByte, _ := buf.ReadByte()
leastSignificantByte, err := buf.ReadByte()
if err != nil {
return err
}
mostSignificantByte, err := buf.ReadByte()
if err != nil {
return err
}

value := uint(leastSignificantByte) | uint(mostSignificantByte)<<7
pin := (messageType & 0x0F)
Expand All @@ -289,8 +312,14 @@ func (b *board) process(data []byte) {
digitalMessageRangeEnd >= messageType:

port := messageType & 0x0F
firstBitmask, _ := buf.ReadByte()
secondBitmask, _ := buf.ReadByte()
firstBitmask, err := buf.ReadByte()
if err != nil {
return err
}
secondBitmask, err := buf.ReadByte()
if err != nil {
return err
}
portValue := firstBitmask | (secondBitmask << 7)

for i := 0; i < 8; i++ {
Expand All @@ -307,6 +336,7 @@ func (b *board) process(data []byte) {
for {
b, err := buf.ReadByte()
if err != nil {
// we ran out of bytes before we reached the endSysex so we break
break
}
currentBuffer = append(currentBuffer, b)
Expand Down Expand Up @@ -407,8 +437,9 @@ func (b *board) process(data []byte) {
str := currentBuffer[2:len(currentBuffer)]
gobot.Publish(b.events["string_data"], string(str[:len(str)]))
default:
fmt.Println("bad byte", fmt.Sprintf("0x%x", command))
return errors.New(fmt.Sprintf("bad byte: 0x%x", command))
}
}
}
return
}
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