go lint and documentation tweaks for the firmata package

platforms/firmata/doc.go

@@ -3,9 +3,9 @@ Package firmata provides the Gobot adaptor for microcontrollers that support the
 
 Installing:
 
-	go get github.com/hybridgroup/gobot/platforms/firmata
+	go get -d -u github.com/hybridgroup/gobot/... && go get github.com/hybridgroup/gobot/platforms/firmata
 
-## Example
+Example:
 
 	package main
 

platforms/firmata/firmata.go

@@ -2,7 +2,6 @@ package firmata
 
 import (
 	"bytes"
-	"errors"
 	"fmt"
 	"io"
 	"math"
@@ -51,7 +50,7 @@ const (
 	i2CModeStopReading       byte = 0x03
 )
 
-var defaultInitTimeInterval time.Duration = 1 * time.Second
+var defaultInitTimeInterval = 1 * time.Second
 
 type board struct {
 	serial           io.ReadWriteCloser
@@ -439,7 +438,7 @@ func (b *board) process(data []byte) (err error) {
 				str := currentBuffer[2:len(currentBuffer)]
 				gobot.Publish(b.events["string_data"], string(str[:len(str)]))
 			default:
-				return errors.New(fmt.Sprintf("bad byte: 0x%x", command))
+				return fmt.Errorf("bad byte: 0x%x", command)
 			}
 		}
 	}

platforms/firmata/firmata_adaptor.go

@@ -23,6 +23,7 @@ var _ gpio.ServoWriter = (*FirmataAdaptor)(nil)
 
 var _ i2c.I2c = (*FirmataAdaptor)(nil)
 
+// FirmataAdaptor is the Gobot Adaptor for Firmata based boards
 type FirmataAdaptor struct {
 	name       string
 	port       string
@@ -32,7 +33,7 @@ type FirmataAdaptor struct {
 	connect    func(string) (io.ReadWriteCloser, error)
 }
 
-// NewFirmataAdaptor returns a new firmata adaptor with specified name and optionally accepts:
+// NewFirmataAdaptor returns a new FirmataAdaptor with specified name and optionally accepts:
 //
 //	string: port the FirmataAdaptor uses to connect to a serial port with a baude rate of 57600
 //	io.ReadWriteCloser: connection the FirmataAdaptor uses to communication with the hardware
@@ -63,41 +64,43 @@ func NewFirmataAdaptor(name string, args ...interface{}) *FirmataAdaptor {
 	return f
 }
 
-// Connect returns true if connection to board is succesfull
+// Connect starts a connection to the board.
 func (f *FirmataAdaptor) Connect() (errs []error) {
 	if f.conn == nil {
-		if sp, err := f.connect(f.Port()); err != nil {
+		sp, err := f.connect(f.Port())
+		if err != nil {
 			return []error{err}
-		} else {
-			f.conn = sp
 		}
+		f.conn = sp
 	}
 	f.board = newBoard(f.conn)
 	f.board.connect()
 	return
 }
 
-// close finishes connection to serial port
-// Prints error message on error
+// Disconnect closes the io connection to the board
 func (f *FirmataAdaptor) Disconnect() (err error) {
 	if f.board != nil {
 		return f.board.serial.Close()
 	}
 	return errors.New("no board connected")
 }
 
-// Finalize disconnects firmata adaptor
+// Finalize terminates the firmata connection
 func (f *FirmataAdaptor) Finalize() (errs []error) {
 	if err := f.Disconnect(); err != nil {
 		return []error{err}
 	}
 	return
 }
 
+// Port returns the  FirmataAdaptors port
 func (f *FirmataAdaptor) Port() string { return f.port }
+
+// Name returns the  FirmataAdaptors name
 func (f *FirmataAdaptor) Name() string { return f.name }
 
-// ServoWrite sets angle form 0 to 360 to specified servo pin
+// ServoWrite writes the 0-180 degree angle to the specified pin.
 func (f *FirmataAdaptor) ServoWrite(pin string, angle byte) (err error) {
 	p, err := strconv.Atoi(pin)
 	if err != nil {
@@ -112,7 +115,7 @@ func (f *FirmataAdaptor) ServoWrite(pin string, angle byte) (err error) {
 	return
 }
 
-// PwmWrite writes analog value to specified pin
+// PwmWrite writes the 0-254 value to the specified pin
 func (f *FirmataAdaptor) PwmWrite(pin string, level byte) (err error) {
 	p, err := strconv.Atoi(pin)
 	if err != nil {
@@ -127,7 +130,7 @@ func (f *FirmataAdaptor) PwmWrite(pin string, level byte) (err error) {
 	return
 }
 
-// DigitalWrite writes digital values to specified pin
+// DigitalWrite writes a value to the pin. Acceptable values are 1 or 0.
 func (f *FirmataAdaptor) DigitalWrite(pin string, level byte) (err error) {
 	p, err := strconv.Atoi(pin)
 	if err != nil {
@@ -143,8 +146,8 @@ func (f *FirmataAdaptor) DigitalWrite(pin string, level byte) (err error) {
 	return
 }
 
-// DigitalRead retrieves digital value from specified pin
-// Returns -1 if response from board is timed out
+// DigitalRead retrieves digital value from specified pin.
+// Returns -1 if the response from the board has timed out
 func (f *FirmataAdaptor) DigitalRead(pin string) (val int, err error) {
 	ret := make(chan int)
 
@@ -175,14 +178,15 @@ func (f *FirmataAdaptor) DigitalRead(pin string) (val int, err error) {
 }
 
 // AnalogRead retrieves value from analog pin.
-// NOTE pins are numbered A0-A5, which translate to digital pins 14-19
+// Returns -1 if the response from the board has timed out
 func (f *FirmataAdaptor) AnalogRead(pin string) (val int, err error) {
 	ret := make(chan int)
 
 	p, err := strconv.Atoi(pin)
 	if err != nil {
 		return
 	}
+	// NOTE pins are numbered A0-A5, which translate to digital pins 14-19
 	p = f.digitalPin(p)
 	if err = f.board.setPinMode(byte(p), analog); err != nil {
 		return
@@ -214,14 +218,14 @@ func (f *FirmataAdaptor) digitalPin(pin int) int {
 	return pin + 14
 }
 
-// I2cStart initializes board with i2c configuration
+// I2cStart starts an i2c device at specified address
 func (f *FirmataAdaptor) I2cStart(address byte) (err error) {
 	f.i2cAddress = address
 	return f.board.i2cConfig([]byte{0})
 }
 
-// I2cRead reads from I2c specified size
-// Returns empty byte array if response is timed out
+// I2cRead returns size bytes from the i2c device
+// Returns an empty array if the response from the board has timed out
 func (f *FirmataAdaptor) I2cRead(size uint) (data []byte, err error) {
 	ret := make(chan []byte)
 	if err = f.board.i2cReadRequest(f.i2cAddress, size); err != nil {
@@ -244,7 +248,7 @@ func (f *FirmataAdaptor) I2cRead(size uint) (data []byte, err error) {
 	return []byte{}, nil
 }
 
-// I2cWrite retrieves i2c data
+// I2cWrite writes data to i2c device
 func (f *FirmataAdaptor) I2cWrite(data []byte) (err error) {
 	return f.board.i2cWriteRequest(f.i2cAddress, data)
 }

platforms/firmata/firmata_test.go

@@ -17,7 +17,7 @@ func (NullReadWriteCloser) Read(b []byte) (int, error) {
 	return len(b), nil
 }
 
-var closeErr error = nil
+var closeErr error
 
 func (NullReadWriteCloser) Close() error {
 	return closeErr
@@ -150,11 +150,11 @@ func TestProcess(t *testing.T) {
 	}
 	//i2cReply
 	gobot.Once(b.events["i2c_reply"], func(data interface{}) {
-		i2c_reply := map[string][]byte{
+		i2cReply := map[string][]byte{
 			"slave_address": []byte{9},
 			"register":      []byte{0},
 			"data":          []byte{152, 1, 154}}
-		gobot.Assert(t, data.(map[string][]byte), i2c_reply)
+		gobot.Assert(t, data.(map[string][]byte), i2cReply)
 		sem <- true
 	})
 	b.process([]byte{240, 119, 9, 0, 0, 0, 24, 1, 1, 0, 26, 1, 247})