diff --git a/apps/drivers/blinkm/blinkm.cpp b/apps/drivers/blinkm/blinkm.cpp
index 56265995f3..3fabfd9a54 100644
--- a/apps/drivers/blinkm/blinkm.cpp
+++ b/apps/drivers/blinkm/blinkm.cpp
@@ -92,6 +92,7 @@
 
 #include <nuttx/config.h>
 
+#include <arch/board/board.h>
 #include <drivers/device/i2c.h>
 
 #include <sys/types.h>
@@ -841,7 +842,7 @@ int
 blinkm_main(int argc, char *argv[])
 {
 
-	int i2cdevice = 3;
+	int i2cdevice = PX4_I2C_BUS_EXPANSION;
 	int blinkmadr = 9;
 
 	int x;
diff --git a/apps/drivers/stm32/drv_hrt.c b/apps/drivers/stm32/drv_hrt.c
index bb67d5e6d2..cec0c49ffd 100644
--- a/apps/drivers/stm32/drv_hrt.c
+++ b/apps/drivers/stm32/drv_hrt.c
@@ -125,7 +125,7 @@
 # define HRT_TIMER_VECTOR	STM32_IRQ_TIM8CC
 # define HRT_TIMER_CLOCK	STM32_APB2_TIM8_CLKIN
 # if CONFIG_STM32_TIM8
-#  error must not set CONFIG_STM32_TIM8=y and HRT_TIMER=6
+#  error must not set CONFIG_STM32_TIM8=y and HRT_TIMER=8
 # endif
 #elif HRT_TIMER == 9
 # define HRT_TIMER_BASE		STM32_TIM9_BASE
diff --git a/apps/drivers/stm32/tone_alarm/tone_alarm.cpp b/apps/drivers/stm32/tone_alarm/tone_alarm.cpp
index baa652d8ad..ac5511e60a 100644
--- a/apps/drivers/stm32/tone_alarm/tone_alarm.cpp
+++ b/apps/drivers/stm32/tone_alarm/tone_alarm.cpp
@@ -494,7 +494,7 @@ ToneAlarm::init()
 		return ret;
 
 	/* configure the GPIO to the idle state */
-	stm32_configgpio(GPIO_TONE_ALARM);
+	stm32_configgpio(GPIO_TONE_ALARM_IDLE);
 
 	/* clock/power on our timer */
 	modifyreg32(STM32_RCC_APB1ENR, 0, TONE_ALARM_CLOCK_ENABLE);
@@ -606,6 +606,8 @@ ToneAlarm::start_note(unsigned note)
 	rEGR = GTIM_EGR_UG;	// force a reload of the period
 	rCCER |= TONE_CCER;	// enable the output
 
+	// configure the GPIO to enable timer output
+	stm32_configgpio(GPIO_TONE_ALARM);
 }
 
 void
@@ -616,10 +618,8 @@ ToneAlarm::stop_note()
 
 	/*
 	 * Make sure the GPIO is not driving the speaker.
-	 *
-	 * XXX this presumes PX4FMU and the onboard speaker driver FET.
 	 */
-	stm32_gpiowrite(GPIO_TONE_ALARM, 0);
+	stm32_configgpio(GPIO_TONE_ALARM_IDLE);
 }
 
 void
diff --git a/nuttx/configs/px4fmu/include/board.h b/nuttx/configs/px4fmu/include/board.h
index 8ad56a4c6a..0bc0b30216 100755
--- a/nuttx/configs/px4fmu/include/board.h
+++ b/nuttx/configs/px4fmu/include/board.h
@@ -326,6 +326,7 @@
  */
 #define TONE_ALARM_TIMER	3	/* timer 3 */
 #define TONE_ALARM_CHANNEL	3	/* channel 3 */
+#define GPIO_TONE_ALARM_IDLE	(GPIO_OUTPUT|GPIO_PUSHPULL|GPIO_SPEED_2MHz|GPIO_OUTPUT_CLEAR|GPIO_PORTC|GPIO_PIN8)
 #define GPIO_TONE_ALARM		(GPIO_ALT|GPIO_AF2|GPIO_SPEED_2MHz|GPIO_FLOAT|GPIO_PUSHPULL|GPIO_PORTC|GPIO_PIN8)
 
 /************************************************************************************