1 #include <libopencm3/cm3/nvic.h>
2 #include <libopencm3/stm32/rcc.h>
3 #include <libopencm3/stm32/gpio.h>
4 #include <libopencm3/stm32/timer.h>
8 if (TIM_SR(TIM3) & TIM_SR_UIF) {
9 TIM_SR(TIM3) &= ~TIM_SR_UIF;
10 gpio_toggle(GPIOC, GPIO13);
16 rcc_clock_setup_in_hse_8mhz_out_72mhz();
17 rcc_periph_clock_enable(RCC_GPIOC);
18 rcc_periph_clock_enable(RCC_TIM3);
20 // PC13 = BluePill LED
21 gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
23 timer_set_prescaler(TIM3, 35999); // 72 MHz / 36000 = 2 kHz
24 timer_set_mode(TIM3, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP);
25 timer_set_period(TIM3, 199); // 200 ticks = 100 ms
26 timer_update_on_overflow(TIM3);
27 timer_enable_irq(TIM3, TIM_DIER_UIE);
28 nvic_enable_irq(NVIC_TIM3_IRQ);
29 timer_enable_counter(TIM3);