diff --git a/gpio.go b/gpio.go
index 3d7baf7..e124cce 100644
--- a/gpio.go
+++ b/gpio.go
@@ -151,6 +151,13 @@ type GPIODriver interface {
 var gpioDriverInitialized bool
 var gpioDriverInstance GPIODriver
 
+// SetGpioDriver should be used only for testing purpose.It makes possible to unit test embd gpio functionality
+// it overrides the gpioDriverInstance
+func SetGpioDriver(drv GPIODriver, initialized bool) {
+	gpioDriverInstance = drv
+	gpioDriverInitialized = initialized
+}
+
 // InitGPIO initializes the GPIO driver.
 func InitGPIO() error {
 	if gpioDriverInitialized {
diff --git a/i2c.go b/i2c.go
index 6a5d1ec..9f39296 100644
--- a/i2c.go
+++ b/i2c.go
@@ -43,6 +43,13 @@ type I2CDriver interface {
 var i2cDriverInitialized bool
 var i2cDriverInstance I2CDriver
 
+// SetI2cDriver should be used only for testing purpose.It makes possible to unit test embd i2c functionality.
+// it overrides the i2cDriverInstance
+func SetI2cDriver(drv I2CDriver, initialized bool) {
+	i2cDriverInstance = drv
+	i2cDriverInitialized = initialized
+}
+
 // InitI2C initializes the I2C driver.
 func InitI2C() error {
 	if i2cDriverInitialized {
diff --git a/spi.go b/spi.go
index db5b029..365b3b1 100644
--- a/spi.go
+++ b/spi.go
@@ -56,6 +56,13 @@ type SPIDriver interface {
 var spiDriverInitialized bool
 var spiDriverInstance SPIDriver
 
+// SetSPIDriver should be used only for testing purpose.It makes possible to unit test embd spi functionality.
+// it overrides spiDriverInstance
+func SetSPIDriver(drv SPIDriver, initialized bool) {
+	spiDriverInstance = drv
+	spiDriverInitialized = initialized
+}
+
 // InitSPI initializes the SPI driver.
 func InitSPI() error {
 	if spiDriverInitialized {