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@ -13,6 +13,6 @@ CPU_FLAGS := -mthumb -mcpu=cortex-m3 -msoft-float -mfix-cortex-m3-ldrd
arm-none-eabi-objcopy -Obinary $*.elf $*.bin
flash: main.bin
st-flash write /dev/stlinkv1_4 main.bin 0x08000000
st-flash --reset write main.bin 0x08000000
.PHONY: flash

@ -13,6 +13,7 @@
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/f1/exti.h>
#include <libopencm3/stm32/f1/nvic.h>
#include <libopencm3/stm32/f1/timer.h>
#include <stdbool.h>
//#define DELAY 8000000 // Should be a second, or maybe not (second iff 8MHz clk, 1/3second if 24MHz clk) // Too long!!
@ -22,13 +23,21 @@
volatile enum {FORWARD, BACKWARD} direction;
volatile bool running = false;
void setup (void) { // All the blackbox code
void setup_system (void) {
// Set up clock
rcc_clock_setup_in_hse_8mhz_out_24mhz();
}
// Enable the two GPIOs
void setup_gpio_out (void) {
// Enable clock for GPIO C
rcc_periph_clock_enable(RCC_GPIOC);
// GPIO C8 amd C9 are the two LEDs
gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO8 | GPIO9);
}
void setup_exti0_in (void) {
// Enable clock for GPIO A
rcc_periph_clock_enable(RCC_GPIOA);
// Enable AFIO (we need that to map GPIO to EXTI)
@ -39,8 +48,6 @@ void setup (void) { // All the blackbox code
// This one is for EXTI0 ~~ GPIOx0 pins
nvic_enable_irq(NVIC_EXTI0_IRQ);
// GPIO C8 amd C9 are the two LEDs
gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO8 | GPIO9);
// GPIO A0 is the push button
// And we set it as a regular button and enable its interrupts in the next block
@ -55,6 +62,32 @@ void setup (void) { // All the blackbox code
exti_enable_request(EXTI0);
}
void setup_tim6_periodic_irq (void) {
// Enable clock
rcc_periph_clock_enable(RCC_TIM6);
// Config:
// Set prescaler
timer_set_prescaler(TIM6, 65535);
// Set counter value
timer_set_period(TIM6, 183);
// Enable interrupts in NVIC
nvic_enable_irq(NVIC_TIM6_IRQ);
// Enable sending interrupts from the timer
timer_enable_irq(TIM6, TIM_DIER_UIE);
// Finally, enable the counter
timer_enable_counter(TIM6);
}
void setup (void) {
setup_system();
setup_gpio_out();
setup_exti0_in();
setup_tim6_periodic_irq();
}
// libopencm3 has a pre-declared interrupt handlers, so it needs to have this name
void exti0_isr (void) {
// Clear the interrupt
@ -70,12 +103,25 @@ void exti0_isr (void) {
running = true;
}
void tim6_isr (void) {
timer_clear_flag(TIM6, TIM_SR_UIF);
// Just change value of GPIO C9 (green LED)
uint16_t cur = gpio_get(GPIOC, GPIO9);
if (cur) {
gpio_clear(GPIOC, GPIO9);
} else {
gpio_set(GPIOC, GPIO9);
}
}
int main (void) {
setup();
while (true) __asm ("wfi");
#ifdef NOT_ACTUALLY_DEFINED
// Array of what leds should be on
uint16_t states[4] = {0, GPIO9, GPIO8, GPIO9 | GPIO8};
uint16_t states[4] = {0, 0, GPIO8, GPIO8};
char state = 0;
int i;
@ -90,8 +136,9 @@ int main (void) {
state = (direction == FORWARD ? (state + 1)%4 : (/*state+4-1*/ state+3)%4 ); // New state
gpio_set(GPIOC, states[state]);
gpio_clear(GPIOC, (GPIO8 | GPIO9) ^ states[state]);
gpio_clear(GPIOC, (GPIO8) ^ states[state]);
}
#endif
return 0;
}

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