i2c: correct reads to use simple file reads for ads1015 adc, and incr…

…ease test coverage

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

drivers/i2c/ads1015_driver.go

@@ -141,7 +141,7 @@ func (d *ADS1015Driver) ReadADCDifference01() (val int16, err error) {
 
 	cfg |= ADS1015RegConfigMuxDiff01
 
-	if err = d.connection.WriteWordData(ADS1015RegPointerConfig, cfg); err != nil {
+	if _, err = d.connection.Write([]byte{ADS1015RegPointerConfig, byte(cfg >> 8), byte(cfg & 0xff)}); err != nil {
 		return
 	}
 
@@ -159,7 +159,7 @@ func (d *ADS1015Driver) ReadADCDifference23() (val int16, err error) {
 
 	cfg |= ADS1015RegConfigMuxDiff23
 
-	if err = d.connection.WriteWordData(ADS1015RegPointerConfig, cfg); err != nil {
+	if _, err = d.connection.Write([]byte{ADS1015RegPointerConfig, byte(cfg >> 8), byte(cfg & 0xff)}); err != nil {
 		return
 	}
 

drivers/i2c/ads1015_driver_test.go

@@ -48,6 +48,12 @@ func TestADS1015DriverOptions(t *testing.T) {
 	gobottest.Assert(t, d.gain, uint16(ADS1015RegConfigPga2048V))
 }
 
+func TestADS1015StartAndHalt(t *testing.T) {
+	d, _ := initTestADS1015DriverWithStubbedAdaptor()
+	gobottest.Assert(t, d.Start(), nil)
+	gobottest.Assert(t, d.Halt(), nil)
+}
+
 func TestADS1015StartConnectError(t *testing.T) {
 	d, adaptor := initTestADS1015DriverWithStubbedAdaptor()
 	adaptor.Testi2cConnectErr(true)
@@ -69,6 +75,18 @@ func TestADS1015DriverAnalogRead(t *testing.T) {
 	gobottest.Assert(t, val, 1584)
 	gobottest.Assert(t, err, nil)
 
+	val, err = d.AnalogRead("1")
+	gobottest.Assert(t, val, 1584)
+	gobottest.Assert(t, err, nil)
+
+	val, err = d.AnalogRead("2")
+	gobottest.Assert(t, val, 1584)
+	gobottest.Assert(t, err, nil)
+
+	val, err = d.AnalogRead("3")
+	gobottest.Assert(t, val, 1584)
+	gobottest.Assert(t, err, nil)
+
 	val, err = d.AnalogRead("0-1")
 	gobottest.Assert(t, val, 1584)
 	gobottest.Assert(t, err, nil)
@@ -96,3 +114,21 @@ func TestADS1015DriverAnalogReadInvalidPin(t *testing.T) {
 	_, err := d.AnalogRead("99")
 	gobottest.Assert(t, err, errors.New("Invalid channel."))
 }
+
+func TestADS1015DriverAnalogReadWriteError(t *testing.T) {
+	d, a := initTestADS1015DriverWithStubbedAdaptor()
+	d.Start()
+
+	a.i2cWriteImpl = func([]byte) (int, error) {
+		return 0, errors.New("write error")
+	}
+
+	_, err := d.AnalogRead("0")
+	gobottest.Assert(t, err, errors.New("write error"))
+
+	_, err = d.AnalogRead("0-1")
+	gobottest.Assert(t, err, errors.New("write error"))
+
+	_, err = d.AnalogRead("2-3")
+	gobottest.Assert(t, err, errors.New("write error"))
+}