spi: Add MCP3202, MCP3204, MCP3208, and MCP3304 drivers

Signed-off-by: deadprogram <[email protected]>

drivers/spi/mcp3002.go

@@ -7,8 +7,8 @@ import (
 	"gobot.io/x/gobot"
 )
 
-// MCP3002DriverMaxChannel is the number of channels (plus one) of this A/D converter.
-const MCP3002DriverMaxChannel = 1
+// MCP3002DriverMaxChannel is the number of channels of this A/D converter.
+const MCP3002DriverMaxChannel = 2
 
 // MCP3002Driver is a driver for the MCP3002 A/D converter.
 type MCP3002Driver struct {
@@ -59,7 +59,7 @@ func (d *MCP3002Driver) Halt() (err error) {
 
 // Read reads the current analog data for the desired channel.
 func (d *MCP3002Driver) Read(channel int) (result int, err error) {
-	if channel < 0 || channel > MCP3002DriverMaxChannel {
+	if channel < 0 || channel > MCP3002DriverMaxChannel-1 {
 		return 0, errors.New("Invalid channel for read")
 	}
 

drivers/spi/mcp3004.go

@@ -7,7 +7,7 @@ import (
 	"gobot.io/x/gobot"
 )
 
-// MCP3004DriverMaxChannel is the number of channels (plus one) of this A/D converter.
+// MCP3004DriverMaxChannel is the number of channels of this A/D converter.
 const MCP3004DriverMaxChannel = 3
 
 // MCP3004Driver is a driver for the MCP3008 A/D converter.
@@ -59,7 +59,7 @@ func (d *MCP3004Driver) Halt() (err error) {
 
 // Read reads the current analog data for the desired channel.
 func (d *MCP3004Driver) Read(channel int) (result int, err error) {
-	if channel < 0 || channel > MCP3004DriverMaxChannel {
+	if channel < 0 || channel > MCP3004DriverMaxChannel-1 {
 		return 0, errors.New("Invalid channel for read")
 	}
 

drivers/spi/mcp3008.go

@@ -7,8 +7,8 @@ import (
 	"gobot.io/x/gobot"
 )
 
-// MCP3008DriverMaxChannel is the number of channels (plus one) of this A/D converter.
-const MCP3008DriverMaxChannel = 7
+// MCP3008DriverMaxChannel is the number of channels of this A/D converter.
+const MCP3008DriverMaxChannel = 8
 
 // MCP3008Driver is a driver for the MCP3008 A/D converter.
 type MCP3008Driver struct {
@@ -59,7 +59,7 @@ func (d *MCP3008Driver) Halt() (err error) {
 
 // Read reads the current analog data for the desired channel.
 func (d *MCP3008Driver) Read(channel int) (result int, err error) {
-	if channel < 0 || channel > MCP3008DriverMaxChannel {
+	if channel < 0 || channel > MCP3008DriverMaxChannel-1 {
 		return 0, errors.New("Invalid channel for read")
 	}
 

drivers/spi/mcp3202.go

@@ -0,0 +1,90 @@
+package spi
+
+import (
+	"errors"
+	"strconv"
+
+	"gobot.io/x/gobot"
+)
+
+// MCP3202DriverMaxChannel is the number of channels of this A/D converter.
+const MCP3202DriverMaxChannel = 2
+
+// MCP3202Driver is a driver for the MCP3202 A/D converter.
+type MCP3202Driver struct {
+	name       string
+	connector  Connector
+	connection Connection
+}
+
+// NewMCP3202Driver creates a new Gobot Driver for MCP3202Driver A/D converter
+//
+// Params:
+//      a *Adaptor - the Adaptor to use with this Driver
+//
+func NewMCP3202Driver(a Connector) *MCP3202Driver {
+	d := &MCP3202Driver{
+		name:      gobot.DefaultName("MCP3202"),
+		connector: a,
+	}
+	return d
+}
+
+// Name returns the name of the device.
+func (d *MCP3202Driver) Name() string { return d.name }
+
+// SetName sets the name of the device.
+func (d *MCP3202Driver) SetName(n string) { d.name = n }
+
+// Connection returns the Connection of the device.
+func (d *MCP3202Driver) Connection() gobot.Connection { return d.connection.(gobot.Connection) }
+
+// Start initializes the driver.
+func (d *MCP3202Driver) Start() (err error) {
+	bus := d.connector.GetSpiDefaultBus()
+	mode := d.connector.GetSpiDefaultMode()
+	maxSpeed := d.connector.GetSpiDefaultMaxSpeed()
+	d.connection, err = d.connector.GetSpiConnection(bus, mode, maxSpeed)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Halt stops the driver.
+func (d *MCP3202Driver) Halt() (err error) {
+	d.connection.Close()
+	return
+}
+
+// Read reads the current analog data for the desired channel.
+func (d *MCP3202Driver) Read(channel int) (result int, err error) {
+	if channel < 0 || channel > MCP3202DriverMaxChannel-1 {
+		return 0, errors.New("Invalid channel for read")
+	}
+
+	tx := make([]byte, 3)
+	tx[0] = 0x01
+	tx[1] = 0xa0 + byte(channel)<<6
+	tx[2] = 0x00
+
+	rx := make([]byte, 3)
+
+	err = d.connection.Tx(tx, rx)
+	if err == nil && len(rx) == 3 {
+		result = int(((rx[1] & 0xf) << 8) + rx[2])
+	}
+
+	return result, err
+}
+
+// AnalogRead returns value from analog reading of specified pin, scaled to 0-1023 value.
+func (d *MCP3202Driver) AnalogRead(pin string) (value int, err error) {
+	channel, _ := strconv.Atoi(pin)
+	value, err = d.Read(channel)
+	if err != nil {
+		value = int(gobot.ToScale(gobot.FromScale(float64(value), 0, 4095), 0, 1023))
+	}
+
+	return
+}

drivers/spi/mcp3202_test.go

@@ -0,0 +1,37 @@
+package spi
+
+import (
+	"testing"
+
+	"gobot.io/x/gobot"
+	"gobot.io/x/gobot/drivers/aio"
+	"gobot.io/x/gobot/gobottest"
+)
+
+var _ gobot.Driver = (*MCP3202Driver)(nil)
+
+// must implement the AnalogReader interface
+var _ aio.AnalogReader = (*MCP3202Driver)(nil)
+
+func initTestMCP3202Driver() *MCP3202Driver {
+	d := NewMCP3202Driver(&TestConnector{})
+	return d
+}
+
+func TestMCP3202DriverStart(t *testing.T) {
+	d := initTestMCP3202Driver()
+	gobottest.Assert(t, d.Start(), nil)
+}
+
+func TestMCP3202DriverHalt(t *testing.T) {
+	d := initTestMCP3202Driver()
+	d.Start()
+	gobottest.Assert(t, d.Halt(), nil)
+}
+
+func TestMCP3202DriverRead(t *testing.T) {
+	d := initTestMCP3202Driver()
+	d.Start()
+
+	// TODO: actual read test
+}

drivers/spi/mcp3204.go

@@ -0,0 +1,90 @@
+package spi
+
+import (
+	"errors"
+	"strconv"
+
+	"gobot.io/x/gobot"
+)
+
+// MCP3204DriverMaxChannel is the number of channels of this A/D converter.
+const MCP3204DriverMaxChannel = 4
+
+// MCP3204Driver is a driver for the MCP3204 A/D converter.
+type MCP3204Driver struct {
+	name       string
+	connector  Connector
+	connection Connection
+}
+
+// NewMCP3204Driver creates a new Gobot Driver for MCP3204Driver A/D converter
+//
+// Params:
+//      a *Adaptor - the Adaptor to use with this Driver
+//
+func NewMCP3204Driver(a Connector) *MCP3204Driver {
+	d := &MCP3204Driver{
+		name:      gobot.DefaultName("MCP3204"),
+		connector: a,
+	}
+	return d
+}
+
+// Name returns the name of the device.
+func (d *MCP3204Driver) Name() string { return d.name }
+
+// SetName sets the name of the device.
+func (d *MCP3204Driver) SetName(n string) { d.name = n }
+
+// Connection returns the Connection of the device.
+func (d *MCP3204Driver) Connection() gobot.Connection { return d.connection.(gobot.Connection) }
+
+// Start initializes the driver.
+func (d *MCP3204Driver) Start() (err error) {
+	bus := d.connector.GetSpiDefaultBus()
+	mode := d.connector.GetSpiDefaultMode()
+	maxSpeed := d.connector.GetSpiDefaultMaxSpeed()
+	d.connection, err = d.connector.GetSpiConnection(bus, mode, maxSpeed)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Halt stops the driver.
+func (d *MCP3204Driver) Halt() (err error) {
+	d.connection.Close()
+	return
+}
+
+// Read reads the current analog data for the desired channel.
+func (d *MCP3204Driver) Read(channel int) (result int, err error) {
+	if channel < 0 || channel > MCP3204DriverMaxChannel-1 {
+		return 0, errors.New("Invalid channel for read")
+	}
+
+	tx := make([]byte, 3)
+	tx[0] = 0x06 + (byte(channel) >> 2)
+	tx[1] = (byte(channel) & 0x03) << 6
+	tx[2] = 0x00
+
+	rx := make([]byte, 3)
+
+	err = d.connection.Tx(tx, rx)
+	if err == nil && len(rx) == 3 {
+		result = int(((rx[1] & 0xf) << 8) + rx[2])
+	}
+
+	return result, err
+}
+
+// AnalogRead returns value from analog reading of specified pin, scaled to 0-1023 value.
+func (d *MCP3204Driver) AnalogRead(pin string) (value int, err error) {
+	channel, _ := strconv.Atoi(pin)
+	value, err = d.Read(channel)
+	if err != nil {
+		value = int(gobot.ToScale(gobot.FromScale(float64(value), 0, 4095), 0, 1023))
+	}
+
+	return
+}

drivers/spi/mcp3204_test.go

@@ -0,0 +1,37 @@
+package spi
+
+import (
+	"testing"
+
+	"gobot.io/x/gobot"
+	"gobot.io/x/gobot/drivers/aio"
+	"gobot.io/x/gobot/gobottest"
+)
+
+var _ gobot.Driver = (*MCP3204Driver)(nil)
+
+// must implement the AnalogReader interface
+var _ aio.AnalogReader = (*MCP3204Driver)(nil)
+
+func initTestMCP3204Driver() *MCP3204Driver {
+	d := NewMCP3204Driver(&TestConnector{})
+	return d
+}
+
+func TestMCP3204DriverStart(t *testing.T) {
+	d := initTestMCP3204Driver()
+	gobottest.Assert(t, d.Start(), nil)
+}
+
+func TestMCP3204DriverHalt(t *testing.T) {
+	d := initTestMCP3204Driver()
+	d.Start()
+	gobottest.Assert(t, d.Halt(), nil)
+}
+
+func TestMCP3204DriverRead(t *testing.T) {
+	d := initTestMCP3204Driver()
+	d.Start()
+
+	// TODO: actual read test
+}