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stm32-better-blink/main.c

59 lines
1.8 KiB
C

/*
* My first project
*
* It blinks LEDs like counting in binary, when the button is pressed, it reverses the order
*
* Build on top of libopenocm3, blackbox parts of code (setup()) copied from
* libopencm3-examples/examples/stm32/f1/stm32vl-discovery/button project
*
* Open source licence, let's say Artistic Licence, although it doesn't matter, as it is local only
*/
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/gpio.h>
#include <stdbool.h>
#define DELAY 8000000 // Should be a second, or maybe not (second iff 8MHz clk, 1/3second if 24MHz clk)
#define STM32F1 1 // Needed for libopencm3
void setup (void) { // All the blackbox code
rcc_clock_setup_in_hse_8mhz_out_24mhz();
rcc_periph_clock_enable(RCC_GPIOC);
rcc_periph_clock_enable(RCC_GPIOA);
gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO8 | GPIO9);
gpio_set_mode(GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO0);
}
void inline wait (int ticks) { // This works in libopenocm3 examples
int i;
for (i=0;i<ticks;i++) __asm__("nop");
return;
}
int main (void) {
setup();
gpio_unset(GPIOC, GPIO8 | GPIO9);
while (gpio_get(GPIOA, GPIO0) == 0);
// Array of what leds should be on
uint16_t states[4] = {0, GPIO9, GPIO8, GPIO9 | GPIO8};
enum {FORWARD, BACKWARD} direction = FORWARD;
bool pressed = true;
char state;
while (true) {
if (/*Button pressed, but was not*/ gpio_get(GPIOA, GPIO0) && (pressed == false) ) {
pressed = true;
direction = (direction == FORWARD ? BACKWARD : FORWARD); // Switch direction
} else /*Button not pressed, possibly released*/ {
pressed = false;
}
state = (direction == FORWARD ? (state + 1)%4 : (/*state+4-1*/ state+3)%4 );
gpio_set(GPIOC, states[state]); //FIXME: This doesn't work, as it does not write 0s to unmentioned pins!!
wait(DELAY);
}
return 0;
}