begriffs open source - cmsis-driver-bare/blob - demo/gpio.c

   1 #include "Driver_GPIO.h"
   2 #include "stm32f4xx.h"
   3
   4 #include "sram_vtor.h"
   5 #include "debounce.h"
   6
   7 extern ARM_DRIVER_GPIO Driver_GPIOA, Driver_GPIOC;
   8
   9 volatile long gTicks;
  10
  11 void on_tick(void)
  12 {
  13         gTicks++;
  14 }
  15
  16 void delay(uint32_t t)
  17 {
  18         uint32_t start = gTicks;
  19         // modular subtraction is resillient against
  20         // up to a single overflow in gTicks
  21         while (gTicks - start < t)
  22                 __WFI();
  23 }
  24
  25 void init_clock(void)
  26 {
  27         SystemCoreClockUpdate();
  28         SysTick_Config(SystemCoreClock / 1000);
  29         NVIC_SetVector(SysTick_IRQn, (uintptr_t)on_tick);
  30         NVIC_EnableIRQ(SysTick_IRQn);
  31
  32         RCC->AHB1ENR |=
  33                 RCC_AHB1ENR_GPIOAEN | RCC_AHB1ENR_GPIOCEN;
  34         (void)RCC->AHB1ENR;
  35         (void)RCC->AHB1ENR;
  36 }
  37
  38 int main(void)
  39 {
  40         ARM_DRIVER_GPIO *ioa = &Driver_GPIOA, *ioc = &Driver_GPIOC;
  41
  42         NVIC_Relocate_VTOR();
  43         init_clock();
  44
  45         ioa->Setup(5, NULL);
  46         ioa->SetDirection(5, ARM_GPIO_OUTPUT);
  47         ioc->Setup(13, NULL);
  48
  49         sample_state button_samples;
  50         debounce_init(&button_samples, true, 5);
  51         bool led = true;
  52         ioa->SetOutput(5, led);
  53
  54         while (1)
  55         {
  56                 bool *stable;
  57                 stable = debounce(
  58                         &button_samples, ioc->GetInput(13));
  59                 if (stable && !*stable)
  60                 {
  61                         led = !led;
  62                         ioa->SetOutput(5, led);
  63                 }
  64                 delay(10);
  65         }
  66 }