diff --git a/platforms/intel-iot/edison/edison_adaptor.go b/platforms/intel-iot/edison/edison_adaptor.go
index 12dffba4..929f80c2 100644
--- a/platforms/intel-iot/edison/edison_adaptor.go
+++ b/platforms/intel-iot/edison/edison_adaptor.go
@@ -14,6 +14,26 @@ import (
 
 var i2cLocation = "/dev/i2c-6"
 
+// writeFile validates file existence and writes data into it
+var writeFile = func(name, data string) error {
+	if _, err := os.Stat(name); err == nil {
+		err := ioutil.WriteFile(
+			name,
+			[]byte(data),
+			0644,
+		)
+		if err != nil {
+			return err
+		}
+	} else {
+		return errors.New("File doesn't exist: " + name)
+	}
+	return nil
+}
+var readFile = func(path string) ([]byte, error) {
+	return ioutil.ReadFile(path)
+}
+
 type mux struct {
 	pin   int
 	value int
@@ -147,23 +167,6 @@ var sysfsPinMap = map[string]sysfsPin{
 	},
 }
 
-// writeFile validates file existence and writes data into it
-var writeFile = func(name, data string) error {
-	if _, err := os.Stat(name); err == nil {
-		err := ioutil.WriteFile(
-			name,
-			[]byte(data),
-			0644,
-		)
-		if err != nil {
-			return err
-		}
-	} else {
-		return errors.New("File doesn't exist: " + name)
-	}
-	return nil
-}
-
 // changePinMode writes pin mode to current_pinmux file
 func changePinMode(pin, mode string) {
 	err := writeFile(
@@ -314,7 +317,7 @@ func (e *EdisonAdaptor) PwmWrite(pin string, val byte) {
 
 // AnalogRead returns value from analog reading of specified pin
 func (e *EdisonAdaptor) AnalogRead(pin string) int {
-	buf, err := ioutil.ReadFile(
+	buf, err := readFile(
 		"/sys/bus/iio/devices/iio:device1/in_voltage" + pin + "_raw",
 	)
 	if err != nil {
diff --git a/platforms/intel-iot/edison/edison_adaptor_test.go b/platforms/intel-iot/edison/edison_adaptor_test.go
index 6235b09c..08aef957 100644
--- a/platforms/intel-iot/edison/edison_adaptor_test.go
+++ b/platforms/intel-iot/edison/edison_adaptor_test.go
@@ -17,15 +17,20 @@ func initTestEdisonAdaptor() *EdisonAdaptor {
 	writeFile = func(name, data string) error {
 		return nil
 	}
+	readFile = func(name string) ([]byte, error) {
+		return []byte("11"), nil
+	}
 	a := NewEdisonAdaptor("myAdaptor")
 	a.Connect()
-	a.DigitalWrite("3", 1)
-	a.i2cDevice = new(gobot.NullReadWriteCloser)
 	return a
 }
 
 func TestEdisonAdaptorFinalize(t *testing.T) {
-	gobot.Assert(t, initTestEdisonAdaptor().Finalize(), true)
+	a := initTestEdisonAdaptor()
+	a.DigitalWrite("3", 1)
+	a.PwmWrite("5", 100)
+	a.i2cDevice = new(gobot.NullReadWriteCloser)
+	gobot.Assert(t, a.Finalize(), true)
 }
 
 func TestEdisonAdaptorDigitalIO(t *testing.T) {
@@ -62,3 +67,35 @@ func TestEdisonAdaptorI2c(t *testing.T) {
 	a.I2cWrite([]byte{0x00, 0x01})
 	gobot.Assert(t, a.I2cRead(2), make([]byte, 2))
 }
+
+func TestEdisonAdaptorPwm(t *testing.T) {
+	a := initTestEdisonAdaptor()
+	lastWritePath := ""
+	lastReadPath := ""
+	lastWriteData := ""
+
+	writeFile = func(path, data string) (err error) {
+		lastWritePath = path
+		lastWriteData = data
+		return
+	}
+
+	readFile = func(path string) (b []byte, err error) {
+		lastReadPath = path
+		return []byte("100\n"), nil
+	}
+	a.PwmWrite("5", 100)
+	gobot.Assert(t, lastWritePath, "/sys/class/pwm/pwmchip0/pwm1/duty_cycle")
+}
+
+func TestEdisonAdaptorAnalog(t *testing.T) {
+	a := initTestEdisonAdaptor()
+	lastReadPath := ""
+	readFile = func(path string) (b []byte, err error) {
+		lastReadPath = path
+		return []byte("100\n"), nil
+	}
+	i := a.AnalogRead("0")
+	gobot.Assert(t, lastReadPath, "/sys/bus/iio/devices/iio:device1/in_voltage0_raw")
+	gobot.Assert(t, i, 100)
+}
diff --git a/platforms/intel-iot/edison/pwm_pin.go b/platforms/intel-iot/edison/pwm_pin.go
index 3fa864a5..8730c2bb 100644
--- a/platforms/intel-iot/edison/pwm_pin.go
+++ b/platforms/intel-iot/edison/pwm_pin.go
@@ -1,9 +1,6 @@
 package edison
 
-import (
-	"io/ioutil"
-	"strconv"
-)
+import "strconv"
 
 // pwmPath returns pwm base path
 func pwmPath() string {
@@ -57,7 +54,7 @@ func (p *pwmPin) enable(val string) {
 
 // period reads from pwm period path and returns value
 func (p *pwmPin) period() string {
-	buf, err := ioutil.ReadFile(pwmPeriodPath(p.pin))
+	buf, err := readFile(pwmPeriodPath(p.pin))
 	if err != nil {
 		panic(err)
 	}