diff --git a/lib/onewire_master.c b/lib/onewire_master.c
index 51f444f..186cb72 100644
--- a/lib/onewire_master.c
+++ b/lib/onewire_master.c
@@ -15,7 +15,7 @@
 /** library for 1-wire protocol as master
  *  @file
  *  @author King Kévin <kingkevin@cuvoodoo.info>
- *  @date 2017-2018
+ *  @date 2017-2020
  *  @note peripherals used: timer @ref onewire_master_timer, GPIO @ref onewire_master_gpio
  *  @note overdrive mode is not provided
  *  @implements 1-Wire protocol description from Book of iButton Standards
@@ -38,6 +38,13 @@
 #include "interrupt.h" // runtime interrupt table
 #include "onewire_master.h" // own definitions
 
+/** @defgroup onewire_master_gpio GPIO used for 1-wire signal
+ *  @note external pull-up resistor on pin is required (< 5 kOhm)
+ *  @{
+ */
+#define ONEWIRE_MASTER_PIN PC9  /**< GPIO pin */
+/** @} */
+
 /** @defgroup onewire_master_timer timer used to measure 1-wire signal timing
  *  @{
  */
@@ -83,7 +90,7 @@ void TIM_ISR(ONEWIRE_MASTER_TIMER)(void)
 			case ONEWIRE_STATE_MASTER_RESET: // reset pulse has been started
 				timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC4IF); // clear output compare flag
 				timer_enable_irq(TIM(ONEWIRE_MASTER_TIMER), TIM_DIER_CC4IE); // enable compare interrupt for presence detection
-				gpio_set(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN)); // set signal high again for slaves to respond
+				gpio_set(GPIO_PORT(ONEWIRE_MASTER_PIN),GPIO_PIN(ONEWIRE_MASTER_PIN)); // set signal high again for slaves to respond
 				onewire_master_state = ONEWIRE_STATE_SLAVE_PRESENCE; // set new state
 				break;
 			case ONEWIRE_STATE_SLAVE_PRESENCE: // waiting for slave presence but none received
@@ -93,8 +100,8 @@ void TIM_ISR(ONEWIRE_MASTER_TIMER)(void)
 				break;
 			case ONEWIRE_STATE_MASTER_READ: // end of time slot and recovery time for reading bit
 			case ONEWIRE_STATE_MASTER_WRITE: // end of time slot and recovery time for writing bit
-				if (buffer_bit<buffer_size) { // check if byte to read/write are remaining
-					gpio_clear(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN)); // pull signal low to start next slot
+				if (buffer_bit < buffer_size) { // check if byte to read/write are remaining
+					gpio_clear(GPIO_PORT(ONEWIRE_MASTER_PIN),GPIO_PIN(ONEWIRE_MASTER_PIN)); // pull signal low to start next slot
 				} else { // all bytes read/written
 					timer_disable_counter(TIM(ONEWIRE_MASTER_TIMER)); // disable timer
  					timer_disable_irq(TIM(ONEWIRE_MASTER_TIMER), TIM_DIER_CC1IE); // disable compare interrupt for master pull low
@@ -109,14 +116,14 @@ void TIM_ISR(ONEWIRE_MASTER_TIMER)(void)
  				timer_disable_irq(TIM(ONEWIRE_MASTER_TIMER), TIM_DIER_CC2IE); // disable all compare interrupt
  				timer_disable_irq(TIM(ONEWIRE_MASTER_TIMER), TIM_DIER_CC3IE); // disable all compare interrupt
  				timer_disable_irq(TIM(ONEWIRE_MASTER_TIMER), TIM_DIER_CC4IE); // disable all compare interrupt
-				gpio_set(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN)); // pull signal high (idle state)
+				gpio_set(GPIO_PORT(ONEWIRE_MASTER_PIN),GPIO_PIN(ONEWIRE_MASTER_PIN)); // pull signal high (idle state)
 				onewire_master_state = ONEWIRE_STATE_ERROR; // indicate error
 		}
 	} else if (timer_get_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC1IF)) { // compare event happened for master pull low end for read
 		timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC1IF); // clear flag
 		switch (onewire_master_state) {
 			case ONEWIRE_STATE_MASTER_READ: // master has to read a bit
-				gpio_set(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN)); // pull signal high to end time slot
+				gpio_set(GPIO_PORT(ONEWIRE_MASTER_PIN),GPIO_PIN(ONEWIRE_MASTER_PIN)); // pull signal high to end time slot
 				break;
 			default: // unknown state for this stage
 				break; // let the overflow handle the error if any
@@ -125,9 +132,9 @@ void TIM_ISR(ONEWIRE_MASTER_TIMER)(void)
 		timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC2IF); // clear flag
 		switch (onewire_master_state) {
 			case ONEWIRE_STATE_MASTER_WRITE: // master has to write a bit
-				if (buffer_bit<buffer_size) { // check if byte to send are remaining
-					if (buffer[buffer_bit/8]&(1<<(buffer_bit%8))) { // check bit (LSb first)
-						gpio_set(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN)); // set signal high again to write "1"
+				if (buffer_bit < buffer_size) { // check if byte to send are remaining
+					if (buffer[buffer_bit / 8] & (1 << (buffer_bit % 8))) { // check bit (LSb first)
+						gpio_set(GPIO_PORT(ONEWIRE_MASTER_PIN),GPIO_PIN(ONEWIRE_MASTER_PIN)); // set signal high again to write "1"
 					}
 					buffer_bit++; // got to next bit
 				} else {
@@ -137,8 +144,8 @@ void TIM_ISR(ONEWIRE_MASTER_TIMER)(void)
 				break;
 			case ONEWIRE_STATE_MASTER_READ: // master has to read a bit set by slave
 				if (buffer_bit<buffer_size) { // check if byte to send are remaining
-					if (gpio_get(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN))) { // check if the slave kept it low
-						buffer[buffer_bit/8] |= (1<<(buffer_bit%8)); // save bit "1"
+					if (gpio_get(GPIO_PORT(ONEWIRE_MASTER_PIN),GPIO_PIN(ONEWIRE_MASTER_PIN))) { // check if the slave kept it low
+						buffer[buffer_bit / 8] |= (1 << (buffer_bit % 8)); // save bit "1"
 					} else {
 						buffer[buffer_bit/8] &= ~(1<<(buffer_bit%8)); // save bit "0"
 					}
@@ -153,10 +160,10 @@ void TIM_ISR(ONEWIRE_MASTER_TIMER)(void)
 		}
 	} else if (timer_get_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC3IF)) { // compare event happened for end to time slot
 		timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC3IF); // clear flag
-		gpio_set(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN)); // pull signal high to end time slot
+		gpio_set(GPIO_PORT(ONEWIRE_MASTER_PIN),GPIO_PIN(ONEWIRE_MASTER_PIN)); // pull signal high to end time slot
 	} else if (timer_get_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC4IF)) { // compare event happened for slave presence detection
 		timer_clear_flag(TIM(ONEWIRE_MASTER_TIMER), TIM_SR_CC4IF); // clear flag
-		if (gpio_get(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN))) { // check is a slave let its presence know by pulling low
+		if (gpio_get(GPIO_PORT(ONEWIRE_MASTER_PIN),GPIO_PIN(ONEWIRE_MASTER_PIN))) { // check is a slave let its presence know by pulling low
 			slave_presence = false; // remember no slave(s) responded
 		} else {
 			slave_presence = true; // remember slave(s) responded
@@ -211,7 +218,7 @@ void onewire_master_release(void)
 	rcc_periph_clock_disable(RCC_TIM(ONEWIRE_MASTER_TIMER)); // disable clock for timer peripheral
 
 	// release GPIO
-	gpio_set_mode(GPIO(ONEWIRE_MASTER_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(ONEWIRE_MASTER_PIN)); // put back to input floating
+	gpio_set_mode(GPIO_PORT(ONEWIRE_MASTER_PIN), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO_PIN(ONEWIRE_MASTER_PIN)); // put back to input floating
 
 	// disable timer ISR
 #if defined(ONEWIRE_MASTER_TIMER_USE_INTERRUPT_TABLE) && ONEWIRE_MASTER_TIMER_USE_INTERRUPT_TABLE
@@ -234,8 +241,8 @@ bool onewire_master_reset(void)
 	slave_presence = false; // reset state
 	onewire_master_state = ONEWIRE_STATE_MASTER_RESET; // set new state
 
-	gpio_set_mode(GPIO(ONEWIRE_MASTER_PORT), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(ONEWIRE_MASTER_PIN)); // normal 1-Wire communication (only using external pull-up resistor)
-	gpio_clear(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN)); // pull signal low to start reset (it's not important if it was low in the first place since the reset pulse has no maximum time)
+	gpio_set_mode(GPIO_PORT(ONEWIRE_MASTER_PIN), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO_PIN(ONEWIRE_MASTER_PIN)); // normal 1-Wire communication (only using external pull-up resistor)
+	gpio_clear(GPIO_PORT(ONEWIRE_MASTER_PIN), GPIO_PIN(ONEWIRE_MASTER_PIN)); // pull signal low to start reset (it's not important if it was low in the first place since the reset pulse has no maximum time)
 	timer_enable_counter(TIM(ONEWIRE_MASTER_TIMER)); // start timer
 
 	while (onewire_master_state!=ONEWIRE_STATE_DONE && onewire_master_state!=ONEWIRE_STATE_ERROR) { // wait until reset procedure completed
@@ -267,8 +274,8 @@ static bool onewire_master_write(void)
 	timer_enable_irq(TIM(ONEWIRE_MASTER_TIMER), TIM_DIER_CC3IE); // enable compare interrupt for end of time slow
 
 	// start writing
-	gpio_set_mode(GPIO(ONEWIRE_MASTER_PORT), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(ONEWIRE_MASTER_PIN)); // normal 1-Wire communication (only using external pull-up resistor)
-	gpio_clear(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN)); // pull signal low to start slot
+	gpio_set_mode(GPIO_PORT(ONEWIRE_MASTER_PIN), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO_PIN(ONEWIRE_MASTER_PIN)); // normal 1-Wire communication (only using external pull-up resistor)
+	gpio_clear(GPIO_PORT(ONEWIRE_MASTER_PIN),GPIO_PIN(ONEWIRE_MASTER_PIN)); // pull signal low to start slot
 	timer_enable_counter(TIM(ONEWIRE_MASTER_TIMER)); // start timer
 	while (onewire_master_state!=ONEWIRE_STATE_DONE && onewire_master_state!=ONEWIRE_STATE_ERROR) { // wait until write procedure completed
 		__WFI(); // go to sleep
@@ -303,8 +310,8 @@ static bool onewire_master_read(void)
 	timer_enable_irq(TIM(ONEWIRE_MASTER_TIMER), TIM_DIER_CC3IE); // enable compare interrupt for end of time slow
 
 	// start reading
-	gpio_set_mode(GPIO(ONEWIRE_MASTER_PORT), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(ONEWIRE_MASTER_PIN)); // normal 1-Wire communication (only using external pull-up resistor)
-	gpio_clear(GPIO(ONEWIRE_MASTER_PORT),GPIO(ONEWIRE_MASTER_PIN)); // pull signal low to start slot
+	gpio_set_mode(GPIO_PORT(ONEWIRE_MASTER_PIN), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO_PIN(ONEWIRE_MASTER_PIN)); // normal 1-Wire communication (only using external pull-up resistor)
+	gpio_clear(GPIO_PORT(ONEWIRE_MASTER_PIN), GPIO_PIN(ONEWIRE_MASTER_PIN)); // pull signal low to start slot
 	timer_enable_counter(TIM(ONEWIRE_MASTER_TIMER)); // start timer
 	while (onewire_master_state!=ONEWIRE_STATE_DONE && onewire_master_state!=ONEWIRE_STATE_ERROR) { // wait until read procedure completed
 		__WFI(); // go to sleep
diff --git a/lib/onewire_master.h b/lib/onewire_master.h
index fc5687e..f827dda 100644
--- a/lib/onewire_master.h
+++ b/lib/onewire_master.h
@@ -15,20 +15,12 @@
 /** library for 1-wire protocol as master
  *  @file
  *  @author King Kévin <kingkevin@cuvoodoo.info>
- *  @date 2017-2018
+ *  @date 2017-2020
  *  @note peripherals used: timer @ref onewire_master_timer, GPIO @ref onewire_master_gpio
  *  @note overdrive mode is not provided
  */
 #pragma once
 
-/** @defgroup onewire_master_gpio GPIO used for 1-wire signal
- *  @note external pull-up resistor on pin is required (< 5 kOhm)
- *  @{
- */
-#define ONEWIRE_MASTER_PORT C /**< GPIO port */
-#define ONEWIRE_MASTER_PIN 9  /**< GPIO pin */
-/** @} */
-
 /** setup 1-wire peripheral
  */
 void onewire_master_setup(void);