diff --git a/boards/iot-lab_M3/Makefile.include b/boards/iot-lab_M3/Makefile.include
index eb7ac030c1..7771d42a4b 100644
--- a/boards/iot-lab_M3/Makefile.include
+++ b/boards/iot-lab_M3/Makefile.include
@@ -13,7 +13,7 @@ export AS = $(PREFIX)as
 export LINK = $(PREFIX)gcc
 export SIZE = $(PREFIX)size
 export OBJCOPY = $(PREFIX)objcopy
-export TERMPROG = $(RIOTBASE)/dist/tools/pyterm/pyterm.py
+export TERMPROG = $(RIOTBASE)/dist/tools/pyterm/pyterm -p
 export FLASHER = $(RIOTBOARD)/$(BOARD)/dist/flash.sh
 export DEBUGGER = $(RIOTBOARD)/$(BOARD)/dist/debug.sh
 
diff --git a/boards/iot-lab_M3/drivers/at86rf231_driver.c b/boards/iot-lab_M3/drivers/at86rf231_driver.c
index d4e242d173..91ab5590dd 100644
--- a/boards/iot-lab_M3/drivers/at86rf231_driver.c
+++ b/boards/iot-lab_M3/drivers/at86rf231_driver.c
@@ -46,27 +46,6 @@ GPIO
   SLEEP : PA2 : control sleep, tx & rx state
 */
 
-static inline void RESET_CLR(void)
-{
-    SPI_0_RESET_PORT->BRR = (1 << SPI_0_RESET_PIN);
-}
-static inline void RESET_SET(void)
-{
-    SPI_0_RESET_PORT->BSRR = (1 << SPI_0_RESET_PIN);
-}
-static inline void CSn_SET(void)
-{
-    SPI_0_CS_PORT->BSRR = (1 << SPI_0_CS_PIN);
-}
-static inline void CSn_CLR(void)
-{
-    SPI_0_CS_PORT->BRR = (1 << SPI_0_CS_PIN);
-}
-static inline void SLEEP_CLR(void)
-{
-    SPI_0_SLEEP_PORT->BRR = (1 << SPI_0_SLEEP_PIN);
-}
-
 uint8_t at86rf231_get_status(void)
 {
     return at86rf231_reg_read(AT86RF231_REG__TRX_STATUS)
@@ -74,12 +53,42 @@ uint8_t at86rf231_get_status(void)
 }
 
 
-static void enable_exti_interrupt(void)
+void at86rf231_spi_select(void)
+{
+    SPI_0_CS_PORT->BRR = (1 << SPI_0_CS_PIN);
+}
+
+void at86rf231_spi_unselect(void)
+{
+    SPI_0_CS_PORT->BSRR = (1 << SPI_0_CS_PIN);
+}
+
+void at86rf231_slp_set(void)
+{
+    SPI_0_SLEEP_PORT->BSRR = (1 << SPI_0_SLEEP_PIN);
+}
+
+void at86rf231_slp_clear(void)
+{
+    SPI_0_SLEEP_PORT->BRR = (1 << SPI_0_SLEEP_PIN);
+}
+
+void at86rf231_rst_set(void)
+{
+    SPI_0_RESET_PORT->BRR = (1 << SPI_0_RESET_PIN);
+}
+
+void at86rf231_rst_clear(void)
+{
+    SPI_0_RESET_PORT->BSRR = (1 << SPI_0_RESET_PIN);
+}
+
+void at86rf231_enable_interrupts(void)
 {
     gpio_irq_enable(SPI_0_IRQ0_GPIO);
 }
 
-static void disable_exti_interrupt(void)
+void at86rf231_disable_interrupts(void)
 {
     gpio_irq_disable(SPI_0_IRQ0_GPIO);
 }
@@ -102,10 +111,10 @@ void at86rf231_gpio_spi_interrupts_init(void)
 
     /* IRQ0 */
     gpio_init_in(SPI_0_IRQ0_GPIO, GPIO_NOPULL);
-    gpio_init_int(SPI_0_IRQ0_GPIO, GPIO_NOPULL, GPIO_RISING, at86rf231_rx_irq);
+    gpio_init_int(SPI_0_IRQ0_GPIO, GPIO_NOPULL, GPIO_RISING, (gpio_cb_t)at86rf231_rx_irq, NULL);
 
     /* Connect EXTI4 Line to PC4 pin */
-    enable_exti_interrupt();
+    at86rf231_enable_interrupts();
 
     /* CS */
     gpio_init_out(SPI_0_CS_GPIO, GPIO_NOPULL);
@@ -119,32 +128,28 @@ void at86rf231_gpio_spi_interrupts_init(void)
 void at86rf231_reset(void)
 {
     /* force reset */
-    RESET_CLR();
-    CSn_SET();
-    SLEEP_CLR();
+    at86rf231_rst_set();
 
-    vtimer_usleep(AT86RF231_TIMING__RESET);
+    /* put pins to default values */
+    at86rf231_spi_unselect();
+    at86rf231_slp_clear();
 
-    RESET_SET();
+    /* additional waiting to comply to min rst pulse width */
+    uint8_t delay = 50;
+    while (delay--){}
 
-    /* Wait until TRX_OFF is entered */
-    vtimer_usleep(AT86RF231_TIMING__RESET_TO_TRX_OFF);
+    at86rf231_rst_clear();
 
     /* Send a FORCE TRX OFF command */
     at86rf231_reg_write(AT86RF231_REG__TRX_STATE, AT86RF231_TRX_STATE__FORCE_TRX_OFF);
 
-    /* Wait until TRX_OFF state is entered from P_ON */
-    vtimer_usleep(AT86RF231_TIMING__SLEEP_TO_TRX_OFF);
-
     /* busy wait for TRX_OFF state */
     uint8_t status;
-    uint8_t max_wait = 100;   // TODO : move elsewhere, this is in 10us
+    uint8_t max_wait = 100;
 
     do {
         status = at86rf231_get_status();
 
-        vtimer_usleep(10);
-
         if (!--max_wait) {
             printf("at86rf231 : ERROR : could not enter TRX_OFF mode\n");
             break;
@@ -153,22 +158,14 @@ void at86rf231_reset(void)
              != AT86RF231_TRX_STATUS__TRX_OFF);
 }
 
-void at86rf231_spi_select(void)
+uint8_t at86rf231_spi_transfer_byte(uint8_t byte)
 {
-    CSn_CLR();
+    char ret;
+    spi_transfer_byte(SPI_0, byte, &ret);
+    return ret;
 }
 
-void at86rf231_spi_unselect(void)
+void at86rf231_spi_transfer(const uint8_t *data_out, uint8_t *data_in, uint16_t length)
 {
-    CSn_SET();
-}
-
-void at86rf231_enable_interrupts(void)
-{
-    enable_exti_interrupt();
-}
-
-void at86rf231_disable_interrupts(void)
-{
-    disable_exti_interrupt();
+    spi_transfer_bytes(SPI_0, (char*)data_out, (char*)data_in, length);
 }
diff --git a/boards/iot-lab_M3/drivers/at86rf231_spi1.c b/boards/iot-lab_M3/drivers/at86rf231_spi1.c
index 1b92703825..d72fd032a0 100644
--- a/boards/iot-lab_M3/drivers/at86rf231_spi1.c
+++ b/boards/iot-lab_M3/drivers/at86rf231_spi1.c
@@ -36,14 +36,3 @@ GPIO
   SLEEP : PA2 : control sleep, tx & rx state
 */
 
-uint8_t at86rf231_spi_transfer_byte(uint8_t byte)
-{
-    char ret;
-    spi_transfer_byte(SPI_0, byte, &ret);
-    return ret;
-}
-
-void at86rf231_spi_transfer(const uint8_t *data_out, uint8_t *data_in, uint16_t length)
-{
-    spi_transfer_bytes(SPI_0, (char*)data_out, (char*)data_in, length);
-}
diff --git a/cpu/stm32f1/periph/gpio.c b/cpu/stm32f1/periph/gpio.c
index 393cfc4bb0..365e0cf3a7 100644
--- a/cpu/stm32f1/periph/gpio.c
+++ b/cpu/stm32f1/periph/gpio.c
@@ -31,7 +31,8 @@
 #include "debug.h"
 
 typedef struct {
-    void (*cb)(void);
+    gpio_cb_t cb;       /**< callback called from GPIO interrupt */
+    void *arg;          /**< argument passed to the callback */
 } gpio_state_t;
 
 static gpio_state_t config[GPIO_NUMOF];
@@ -155,7 +156,6 @@ int gpio_init_out(gpio_t dev, gpio_pp_t pullup)
             break;
 #endif
 
-        case GPIO_UNDEFINED:
         default:
             return -1;
     }
@@ -292,7 +292,6 @@ int gpio_init_in(gpio_t dev, gpio_pp_t pullup)
             pin = GPIO_15_PIN;
             break;
 #endif
-        case GPIO_UNDEFINED:
         default:
             return -1;
     }
@@ -309,7 +308,7 @@ int gpio_init_in(gpio_t dev, gpio_pp_t pullup)
     return 0; /* everything alright here */
 }
 
-int gpio_init_int(gpio_t dev, gpio_pp_t pullup, gpio_flank_t flank, void (*cb)(void))
+int gpio_init_int(gpio_t dev, gpio_pp_t pullup, gpio_flank_t flank, gpio_cb_t cb, void *arg)
 {
     int res;
     uint8_t exti_line;
@@ -475,7 +474,6 @@ int gpio_init_int(gpio_t dev, gpio_pp_t pullup, gpio_flank_t flank, void (*cb)(v
             NVIC_EnableIRQ(GPIO_15_IRQ);
             break;
 #endif
-        case GPIO_UNDEFINED:
         default:
             return -1;
     }
@@ -507,7 +505,7 @@ int gpio_init_int(gpio_t dev, gpio_pp_t pullup, gpio_flank_t flank, void (*cb)(v
     return 0;
 }
 
-int gpio_irq_enable(gpio_t dev)
+void gpio_irq_enable(gpio_t dev)
 {
     uint8_t exti_line;
 
@@ -592,21 +590,17 @@ int gpio_irq_enable(gpio_t dev)
             exti_line = GPIO_15_EXTI_LINE;
             break;
 #endif
-
-        case GPIO_UNDEFINED:
-        default:
-            return -1;
     }
     /* save state */
-    int state = (EXTI->IMR & (1 << exti_line) >> exti_line);
+    // int state = (EXTI->IMR & (1 << exti_line) >> exti_line);
 
     /* unmask the pins interrupt channel */
     EXTI->IMR |= (1 << exti_line);
 
-    return state;
+    return;
 }
 
-int gpio_irq_disable(gpio_t dev)
+void gpio_irq_disable(gpio_t dev)
 {
     uint8_t exti_line;
 
@@ -691,17 +685,14 @@ int gpio_irq_disable(gpio_t dev)
             exti_line = GPIO_15_EXTI_LINE;
             break;
 #endif
-        case GPIO_UNDEFINED:
-        default:
-            return -1;
     }
-    /* save state */
-    int state = ((EXTI->IMR & (1 << exti_line)) >> exti_line);
+    // /* save state */
+    // int state = ((EXTI->IMR & (1 << exti_line)) >> exti_line);
 
     /* unmask the pins interrupt channel */
     EXTI->IMR &= ~(1 << exti_line);
 
-    return state;
+    return;
 }
 
 int gpio_read(gpio_t dev)
@@ -806,7 +797,6 @@ int gpio_read(gpio_t dev)
             pin = GPIO_15_PIN;
             break;
 #endif
-        case GPIO_UNDEFINED:
         default:
             return -1;
     }
@@ -827,7 +817,7 @@ int gpio_read(gpio_t dev)
     }
 }
 
-int gpio_set(gpio_t dev)
+void gpio_set(gpio_t dev)
 {
     switch (dev) {
 #ifdef GPIO_0_EN
@@ -910,15 +900,12 @@ int gpio_set(gpio_t dev)
             GPIO_15_PORT->ODR |= (1 << GPIO_15_PIN);
             break;
 #endif
-        case GPIO_UNDEFINED:
-        default:
-            return -1;
     }
 
-    return 0;
+    return;
 }
 
-int gpio_clear(gpio_t dev)
+void gpio_clear(gpio_t dev)
 {
     switch (dev) {
 #ifdef GPIO_0_EN
@@ -1001,32 +988,29 @@ int gpio_clear(gpio_t dev)
             GPIO_15_PORT->ODR &= ~(1 << GPIO_15_PIN);
             break;
 #endif
-        case GPIO_UNDEFINED:
-        default:
-            return -1;
     }
 
-    return 0;
+    return;
 }
 
 
-int gpio_toggle(gpio_t dev)
+void gpio_toggle(gpio_t dev)
 {
     if (gpio_read(dev)) {
-        return gpio_clear(dev);
+        gpio_clear(dev);
     }
     else {
-        return gpio_set(dev);
+        gpio_set(dev);
     }
 }
 
-int gpio_write(gpio_t dev, int value)
+void gpio_write(gpio_t dev, int value)
 {
     if (value) {
-        return gpio_set(dev);
+        gpio_set(dev);
     }
     else {
-        return gpio_clear(dev);
+        gpio_clear(dev);
     }
 }
 
@@ -1035,7 +1019,7 @@ __attribute__((naked)) void isr_exti0(void)
     ISR_ENTER();
     if (EXTI->PR & EXTI_PR_PR0) {
         EXTI->PR |= EXTI_PR_PR0;        /* clear status bit by writing a 1 to it */
-        config[GPIO_0].cb();
+        config[GPIO_0].cb(config[GPIO_0].arg);
     }
 
     if (sched_context_switch_request) {
@@ -1049,7 +1033,7 @@ __attribute__((naked)) void isr_exti1(void)
     ISR_ENTER();
     if (EXTI->PR & EXTI_PR_PR1) {
         EXTI->PR |= EXTI_PR_PR1;        /* clear status bit by writing a 1 to it */
-        config[GPIO_1].cb();
+        config[GPIO_1].cb(config[GPIO_1].arg);
     }
 
     if (sched_context_switch_request) {
@@ -1063,7 +1047,7 @@ __attribute__((naked)) void isr_exti2(void)
     ISR_ENTER();
     if (EXTI->PR & EXTI_PR_PR2) {
         EXTI->PR |= EXTI_PR_PR2;        /* clear status bit by writing a 1 to it */
-        config[GPIO_2].cb();
+        config[GPIO_2].cb(config[GPIO_2].arg);
     }
 
     if (sched_context_switch_request) {
@@ -1077,7 +1061,7 @@ __attribute__((naked)) void isr_exti3(void)
     ISR_ENTER();
     if (EXTI->PR & EXTI_PR_PR3) {
         EXTI->PR |= EXTI_PR_PR3;        /* clear status bit by writing a 1 to it */
-        config[GPIO_3].cb();
+        config[GPIO_3].cb(config[GPIO_3].arg);
     }
 
     if (sched_context_switch_request) {
@@ -1091,7 +1075,7 @@ __attribute__((naked)) void isr_exti4(void)
     ISR_ENTER();
     if (EXTI->PR & EXTI_PR_PR4) {
         EXTI->PR |= EXTI_PR_PR4;        /* clear status bit by writing a 1 to it */
-        config[GPIO_4].cb();
+        config[GPIO_4].cb(config[GPIO_4].arg);
     }
 
     if (sched_context_switch_request) {
@@ -1105,23 +1089,23 @@ __attribute__((naked)) void isr_exti9_5(void)
     ISR_ENTER();
     if (EXTI->PR & EXTI_PR_PR5) {
         EXTI->PR |= EXTI_PR_PR5;        /* clear status bit by writing a 1 to it */
-        config[GPIO_5].cb();
+        config[GPIO_5].cb(config[GPIO_5].arg);
     }
     else if (EXTI->PR & EXTI_PR_PR6) {
         EXTI->PR |= EXTI_PR_PR6;        /* clear status bit by writing a 1 to it */
-        config[GPIO_6].cb();
+        config[GPIO_6].cb(config[GPIO_6].arg);
     }
     else if (EXTI->PR & EXTI_PR_PR7) {
         EXTI->PR |= EXTI_PR_PR7;        /* clear status bit by writing a 1 to it */
-        config[GPIO_7].cb();
+        config[GPIO_7].cb(config[GPIO_7].arg);
     }
     else if (EXTI->PR & EXTI_PR_PR8) {
         EXTI->PR |= EXTI_PR_PR8;        /* clear status bit by writing a 1 to it */
-        config[GPIO_8].cb();
+        config[GPIO_8].cb(config[GPIO_8].arg);
     }
     else if (EXTI->PR & EXTI_PR_PR9) {
         EXTI->PR |= EXTI_PR_PR9;        /* clear status bit by writing a 1 to it */
-        config[GPIO_9].cb();
+        config[GPIO_9].cb(config[GPIO_9].arg);
     }
 
     if (sched_context_switch_request) {
@@ -1135,27 +1119,27 @@ __attribute__((naked)) void isr_exti15_10(void)
     ISR_ENTER();
     if (EXTI->PR & EXTI_PR_PR10) {
         EXTI->PR |= EXTI_PR_PR10;        /* clear status bit by writing a 1 to it */
-        config[GPIO_10].cb();
+        config[GPIO_10].cb(config[GPIO_10].arg);
     }
     else if (EXTI->PR & EXTI_PR_PR11) {
         EXTI->PR |= EXTI_PR_PR11;        /* clear status bit by writing a 1 to it */
-        config[GPIO_11].cb();
+        config[GPIO_11].cb(config[GPIO_11].arg);
     }
     else if (EXTI->PR & EXTI_PR_PR12) {
         EXTI->PR |= EXTI_PR_PR12;        /* clear status bit by writing a 1 to it */
-        config[GPIO_12].cb();
+        config[GPIO_12].cb(config[GPIO_12].arg);
     }
     else if (EXTI->PR & EXTI_PR_PR13) {
         EXTI->PR |= EXTI_PR_PR13;        /* clear status bit by writing a 1 to it */
-        config[GPIO_13].cb();
+        config[GPIO_13].cb(config[GPIO_13].arg);
     }
     else if (EXTI->PR & EXTI_PR_PR14) {
         EXTI->PR |= EXTI_PR_PR14;        /* clear status bit by writing a 1 to it */
-        config[GPIO_14].cb();
+        config[GPIO_14].cb(config[GPIO_14].arg);
     }
     else if (EXTI->PR & EXTI_PR_PR15) {
         EXTI->PR |= EXTI_PR_PR15;        /* clear status bit by writing a 1 to it */
-        config[GPIO_15].cb();
+        config[GPIO_15].cb(config[GPIO_15].arg);
     }
 
     if (sched_context_switch_request) {
diff --git a/cpu/stm32f1/periph/uart.c b/cpu/stm32f1/periph/uart.c
index 896906f7c5..03cabb43ec 100644
--- a/cpu/stm32f1/periph/uart.c
+++ b/cpu/stm32f1/periph/uart.c
@@ -38,8 +38,9 @@
  * @brief Each UART device has to store two callbacks.
  */
 typedef struct {
-    void (*rx_cb)(char);
-    void (*tx_cb)(void);
+    uart_rx_cb_t rx_cb;
+    uart_tx_cb_t tx_cb;
+    void *arg;
 } uart_conf_t;
 
 
@@ -58,7 +59,7 @@ static inline void irq_handler(uart_t uartnum, USART_TypeDef *uart);
 static uart_conf_t config[UART_NUMOF];
 
 
-int uart_init(uart_t uart, uint32_t baudrate, void (*rx_cb)(char), void (*tx_cb)(void))
+int uart_init(uart_t uart, uint32_t baudrate, uart_rx_cb_t rx_cb, uart_tx_cb_t tx_cb, void *arg)
 {
     int res;
 
@@ -84,7 +85,6 @@ int uart_init(uart_t uart, uint32_t baudrate, void (*rx_cb)(char), void (*tx_cb)
             UART_1_DEV->CR1 |= USART_CR1_RXNEIE;
             break;
 #endif
-        case UART_UNDEFINED:
         default:
             return -2;
     }
@@ -131,7 +131,6 @@ int uart_init_blocking(uart_t uart, uint32_t baudrate)
             UART_1_PORT_CLKEN();
             break;
 #endif
-        case UART_UNDEFINED:
         default:
             return -2;
     }
@@ -180,7 +179,6 @@ void uart_tx_begin(uart_t uart)
             UART_1_DEV->CR1 |= USART_CR1_TXEIE;
             break;
 #endif
-        case UART_UNDEFINED:
             break;
     }
 }
@@ -198,7 +196,6 @@ void uart_tx_end(uart_t uart)
             UART_1_DEV->CR1 &= ~USART_CR1_TXEIE;
             break;
 #endif
-        case UART_UNDEFINED:
             break;
     }
 }
@@ -218,7 +215,6 @@ int uart_write(uart_t uart, char data)
             dev = UART_1_DEV;
             break;
 #endif
-        case UART_UNDEFINED:
         default:
             return -1;
     }
@@ -245,7 +241,6 @@ int uart_read_blocking(uart_t uart, char *data)
             dev = UART_1_DEV;
             break;
 #endif
-        case UART_UNDEFINED:
         default:
             return -1;
     }
@@ -271,7 +266,6 @@ int uart_write_blocking(uart_t uart, char data)
             dev = UART_1_DEV;
             break;
 #endif
-        case UART_UNDEFINED:
         default:
             return -1;
     }
diff --git a/cpu/stm32f1/syscalls.c b/cpu/stm32f1/syscalls.c
index 991a0c6f39..b0883e584d 100644
--- a/cpu/stm32f1/syscalls.c
+++ b/cpu/stm32f1/syscalls.c
@@ -46,7 +46,7 @@ caddr_t heap_top = (caddr_t)&_end + 4;
 void _init(void)
 {
 #ifdef MODULE_UART0
-    uart_init(UART_0, 115200, NULL, NULL);
+    uart_init(UART_0, 115200, NULL, NULL, NULL);
 #else
     uart_init_blocking(UART_0, 115200);
 #endif
diff --git a/drivers/include/at86rf231.h b/drivers/include/at86rf231.h
index eab048373e..882633712a 100644
--- a/drivers/include/at86rf231.h
+++ b/drivers/include/at86rf231.h
@@ -31,7 +31,7 @@ typedef struct __attribute__((packed))
 }
 at86rf231_packet_t;
 
-extern int transceiver_pid;
+extern volatile kernel_pid_t transceiver_pid;
 
 #define AT_DRIVER_STATE_DEFAULT     (0)
 #define AT_DRIVER_STATE_SENDING     (1)