Alex Mikhalev
8d24829f67
git-subtree-dir: components/u8g2 git-subtree-split: 45ac4e0edc76c6bc3d808304fccb73c543535ded
42 lines
1.0 KiB
C
42 lines
1.0 KiB
C
/*
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LED blink project for the STM32L011
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Assumes LED at Pin 6, GPIO PA0
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*/
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#include "stm32l011xx.h"
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volatile unsigned long SysTickCount = 0;
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void __attribute__ ((interrupt, used)) SysTick_Handler(void)
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{
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SysTickCount++;
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if ( SysTickCount & 1 )
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GPIOA->BSRR = GPIO_BSRR_BS_0; /* atomic set PA0 */
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else
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GPIOA->BSRR = GPIO_BSRR_BR_0; /* atomic clr PA0 */
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}
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int main()
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{
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RCC->IOPENR |= RCC_IOPENR_IOPAEN; /* Enable clock for GPIO Port A */
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__NOP();
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__NOP();
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GPIOA->MODER &= ~GPIO_MODER_MODE0; /* clear mode for PA0 */
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GPIOA->MODER |= GPIO_MODER_MODE0_0; /* Output mode for PA0 */
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GPIOA->OTYPER &= ~GPIO_OTYPER_OT_0; /* no Push/Pull for PA0 */
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GPIOA->OSPEEDR &= ~GPIO_OSPEEDER_OSPEED0; /* low speed for PA0 */
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GPIOA->PUPDR &= ~GPIO_PUPDR_PUPD0; /* no pullup/pulldown for PA0 */
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GPIOA->BSRR = GPIO_BSRR_BR_0; /* atomic clr PA0 */
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SysTick->LOAD = 2000*500 - 1;
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SysTick->VAL = 0;
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SysTick->CTRL = 7; /* enable, generate interrupt (SysTick_Handler), do not divide by 2 */
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for(;;)
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;
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}
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