rp2040/example/peripherals/gpio/gpio_led/main.c

#include "resets.h"
#include "timer.h"
#include "gpio.h"
#include "uart.h"
#include "stdio.h"

#define LED_PIN  (25)
#define LED_TIME (500 * 1000) /* 500ms */

int main(void)
{
    reset_unreset_blocks_wait(RESETS_BLOCK_IO_BANK0 | RESETS_BLOCK_UART0 | RESETS_BLOCK_TIMER);
    gpio_init(0, GPIO_FUNC_UART | GPIO_PULL_UP | GPIO_DRIVE_4MA); /* UART_TX pin */
    gpio_init(1, GPIO_FUNC_UART | GPIO_PULL_UP | GPIO_SCHMITT | GPIO_PAD_IE | GPIO_PAD_OD); /* UART_RX pin */
    uart_init(uart0_hw, 6 * 1000 * 1000, UART_DATABITS_8 | UART_PARITY_NONE | UART_STOPBITS_1);
    printf("gpio_led example\r\n");

    timer_count_write(0);
    gpio_init(LED_PIN, GPIO_FUNC_NULL | GPIO_OVER_OUT_HIGH | GPIO_OVER_OE_ENABLE | GPIO_PULL_UP | GPIO_DRIVE_4MA); /* LED pin */

    while (1) {
        static int flag = 0;
        static uint64_t tick_led = 0;
        uint64_t tick_now;

        tick_now = timer_count_read();
        if (tick_now >= (tick_led + LED_TIME)) {
            if (flag & 1) {
                gpio_set(LED_PIN);
            } else {
                gpio_clear(LED_PIN);
            }
            flag ^= 1;
            tick_led = tick_now;
            printf("tick_led = %llu\r\n", tick_led);
        }
    }

    return 0;
}