i2c: refactor all i2c drivers to use Address property of Driver. Allows variations to override the default address as discussed in #14 (#30)

Signed-off-by: Ron Evans <ron@hybridgroup.com>

blinkm/blinkm.go

@@ -9,7 +9,8 @@ import (
 
 // Device wraps an I2C connection to a BlinkM device.
 type Device struct {
-	bus machine.I2C
+	bus     machine.I2C
+	Address uint16
 }
 
 // New creates a new BlinkM connection. The I2C bus must already be
@@ -17,38 +18,43 @@ type Device struct {
 //
 // This function only creates the Device object, it does not touch the device.
 func New(bus machine.I2C) Device {
-	return Device{bus}
+	return Device{bus, Address}
+}
+
+// Configure sets up the device for communication
+func (d *Device) Configure() {
+	d.bus.Tx(d.Address, []byte{'o'}, nil)
 }
 
 // Version returns the version of firmware on the BlinkM.
 func (d Device) Version() (major, minor byte, err error) {
 	version := []byte{0, 0}
-	d.bus.ReadRegister(Address, GET_FIRMWARE, version)
+	d.bus.Tx(d.Address, []byte{GET_FIRMWARE}, version)
 	return version[0], version[1], nil
 }
 
 // SetRGB sets the RGB color on the BlinkM.
 func (d Device) SetRGB(r, g, b byte) error {
-	d.bus.WriteRegister(Address, TO_RGB, []byte{r, g, b})
+	d.bus.Tx(d.Address, []byte{TO_RGB, r, g, b}, nil)
 	return nil
 }
 
 // GetRGB gets the current RGB color on the BlinkM.
 func (d Device) GetRGB() (r, g, b byte, err error) {
 	color := []byte{0, 0, 0}
-	d.bus.ReadRegister(Address, GET_RGB, color)
+	d.bus.Tx(d.Address, []byte{GET_RGB}, color)
 	return color[0], color[1], color[2], nil
 }
 
 // FadeToRGB sets the RGB color on the BlinkM by fading from the current color
 // to the new color.
 func (d Device) FadeToRGB(r, g, b byte) error {
-	d.bus.WriteRegister(Address, FADE_TO_RGB, []byte{r, g, b})
+	d.bus.Tx(d.Address, []byte{FADE_TO_RGB, r, g, b}, nil)
 	return nil
 }
 
 // StopScript stops whatever script is currently running on the BlinkM.
 func (d Device) StopScript() error {
-	d.bus.WriteRegister(Address, STOP_SCRIPT, nil)
+	d.bus.Tx(d.Address, []byte{STOP_SCRIPT}, nil)
 	return nil
 }