diff --git a/sys/arm/stm32l011x4/blink/main.c b/sys/arm/stm32l011x4/blink/main.c
index 5c6a48d7..5fa04031 100644
--- a/sys/arm/stm32l011x4/blink/main.c
+++ b/sys/arm/stm32l011x4/blink/main.c
@@ -1,4 +1,8 @@
-/* LED blink project for the STM32L031 */
+/* 
+  LED blink project for the STM32L011 
+  
+  Assumes LED at Pin 6, GPIO PA0
+*/
 
 #include "stm32l031xx.h"
 
@@ -7,10 +11,11 @@ volatile unsigned long SysTickCount = 0;
 void __attribute__ ((interrupt, used)) SysTick_Handler(void)
 {
   SysTickCount++;  
+  
   if ( SysTickCount & 1 )
-    GPIOA->BSRR = GPIO_BSRR_BS_13;		/* atomic set PA13 */
+    GPIOA->BSRR = GPIO_BSRR_BS_0;		/* atomic set PA0 */
   else
-    GPIOA->BSRR = GPIO_BSRR_BR_13;		/* atomic clr PA13 */
+    GPIOA->BSRR = GPIO_BSRR_BR_0;		/* atomic clr PA0 */
 }
 
 int main()
@@ -18,13 +23,15 @@ int main()
   RCC->IOPENR |= RCC_IOPENR_IOPAEN;		/* Enable clock for GPIO Port A */
   __NOP();
   __NOP();
-  GPIOA->MODER &= ~GPIO_MODER_MODE13;	/* clear mode for PA13 */
-  GPIOA->MODER |= GPIO_MODER_MODE13_0;	/* Output mode for PA13 */
-  GPIOA->OTYPER &= ~GPIO_OTYPER_OT_13;	/* no Push/Pull for PA13 */
-  GPIOA->OSPEEDR &= ~GPIO_OSPEEDER_OSPEED13;	/* low speed for PA13 */
-  GPIOA->PUPDR &= ~GPIO_PUPDR_PUPD13;	/* no pullup/pulldown for PA13 */
-  GPIOA->BSRR = GPIO_BSRR_BR_13;		/* atomic clr PA13 */
 
+  GPIOA->MODER &= ~GPIO_MODER_MODE0;	/* clear mode for PA0 */
+  GPIOA->MODER |= GPIO_MODER_MODE0_0;	/* Output mode for PA0 */
+  GPIOA->OTYPER &= ~GPIO_OTYPER_OT_0;	/* no Push/Pull for PA0 */
+  GPIOA->OSPEEDR &= ~GPIO_OSPEEDER_OSPEED0;	/* low speed for PA0 */
+  GPIOA->PUPDR &= ~GPIO_PUPDR_PUPD0;	/* no pullup/pulldown for PA0 */
+  GPIOA->BSRR = GPIO_BSRR_BR_0;		/* atomic clr PA0 */
+
+  
   SysTick->LOAD = 2000*500 - 1;
   SysTick->VAL = 0;
   SysTick->CTRL = 7;   /* enable, generate interrupt (SysTick_Handler), do not divide by 2 */