morse code for debugging

1 files changed, 21 insertions, 2 deletions

diff --git a/main.c b/main.c
index e4594e6..148f053 100644
--- a/main.c
+++ b/main.c
@@ -13,8 +13,14 @@ extern void delay(uint32_t count);
  *   - got to 40MHz clock

  */

 

+void pulse(uint8_t byte);

+

 int main(void)

 {

+	// prepare flash latency for 40MHz operation

+	FLASH->ACR &= ~(FLASH_ACR_LATENCY);

+	FLASH->ACR |= FLASH_ACR_LATENCY_2WS;

+

 	// turn on HSI

 	RCC->CR |= RCC_CR_HSION;

 	while ((RCC->CR & RCC_CR_HSIRDY) != RCC_CR_HSIRDY);

@@ -49,15 +55,28 @@ int main(void)
 	GPIOA->PUPDR &= ~(GPIO_PUPDR_PUPD5 | GPIO_PUPDR_PUPD0);

 	GPIOA->PUPDR |= GPIO_PUPDR_PUPD5_0 | GPIO_PUPDR_PUPD0_1; // pd for button

 

-	while (1) {

+	pulse(*((uint8_t *)0x08080000)); // 0b00100101

+

+	while (1);/* {

 		delay(500);

 		//if (GPIOA->IDR & 0x01)

 			GPIOA->BSRR |= 1 << 5;

 		delay(500);

 		//else

 			GPIOA->BRR |= 1 << 5;

-	}

+	}*/

 }

 

 void _exit(int code)

 { for (;;); }

+

+void pulse(uint8_t byte)

+{

+	int8_t i = 7;

+	do {

+		GPIOA->BSRR |= 1 << 5;

+		delay((byte & (1 << i)) ? 400 : 100);

+		GPIOA->BRR |= 1 << 5;

+		delay((byte & (1 << i)) ? 100 : 400);

+	} while (--i >= 0);

+}