mirror of
https://github.com/mytechnotalent/Embedded-Hacking.git
synced 2026-07-11 14:46:36 +02:00
Kevin Thomas
105 lines
2.6 KiB
C
105 lines
2.6 KiB
C
/**
|
|
******************************************************************************
|
|
* @file main.c
|
|
* @author Kevin Thomas
|
|
* @brief PWM demonstration: LED breathing effect via duty-cycle sweep.
|
|
*
|
|
* Demonstrates PWM output using the PWM driver. A signal on
|
|
* GPIO 25 (onboard LED) sweeps its duty cycle from 0% to 100%
|
|
* and back to produce a smooth breathing effect. The current
|
|
* duty is reported over UART.
|
|
*
|
|
* Wiring:
|
|
* GPIO0 -> UART TX (USB-to-UART adapter RX)
|
|
* GPIO1 -> UART RX (USB-to-UART adapter TX)
|
|
* GPIO25 -> Onboard LED (no external wiring needed)
|
|
*
|
|
******************************************************************************
|
|
* @attention
|
|
*
|
|
* Copyright (c) 2026 Kevin Thomas.
|
|
* All rights reserved.
|
|
*
|
|
* This software is licensed under terms that can be found in the LICENSE file
|
|
* in the root directory of this software component.
|
|
* If no LICENSE file comes with this software, it is provided AS-IS.
|
|
*
|
|
******************************************************************************
|
|
*/
|
|
|
|
#include "rp2350_pwm.h"
|
|
#include "rp2350_uart.h"
|
|
#include "rp2350_delay.h"
|
|
|
|
#define SWEEP_STEP 5
|
|
#define SWEEP_DELAY_MS 50
|
|
|
|
/**
|
|
* @brief Convert a uint8_t to a decimal string.
|
|
* @param value number to convert (0-255)
|
|
* @param buf output buffer (at least 4 bytes)
|
|
* @retval None
|
|
*/
|
|
static void _uint8_to_str(uint8_t value, char *buf)
|
|
{
|
|
uint8_t idx = 0;
|
|
if (value >= 100)
|
|
buf[idx++] = (char)('0' + value / 100);
|
|
if (value >= 10)
|
|
buf[idx++] = (char)('0' + (value / 10) % 10);
|
|
buf[idx++] = (char)('0' + value % 10);
|
|
buf[idx] = '\0';
|
|
}
|
|
|
|
/**
|
|
* @brief Print a duty percentage value as a decimal string over UART.
|
|
* @param duty duty cycle value (0-100)
|
|
* @retval None
|
|
*/
|
|
static void _print_duty(uint8_t duty)
|
|
{
|
|
char buf[4];
|
|
_uint8_to_str(duty, buf);
|
|
uart_puts("Duty: ");
|
|
uart_puts(buf);
|
|
uart_puts("%\r\n");
|
|
}
|
|
|
|
/**
|
|
* @brief Sweep duty cycle upward from 0 to 100 percent.
|
|
* @retval None
|
|
*/
|
|
static void _sweep_up(void)
|
|
{
|
|
for (uint8_t duty = 0; duty <= 100; duty += SWEEP_STEP)
|
|
{
|
|
pwm_set_duty(duty);
|
|
_print_duty(duty);
|
|
delay_ms(SWEEP_DELAY_MS);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @brief Sweep duty cycle downward from 100 to 0 percent.
|
|
* @retval None
|
|
*/
|
|
static void _sweep_down(void)
|
|
{
|
|
for (int8_t duty = 100; duty >= 0; duty -= SWEEP_STEP)
|
|
{
|
|
pwm_set_duty((uint8_t)duty);
|
|
_print_duty((uint8_t)duty);
|
|
delay_ms(SWEEP_DELAY_MS);
|
|
}
|
|
}
|
|
|
|
int main(void)
|
|
{
|
|
uart_puts("PWM initialized: GPIO25\r\n");
|
|
while (1)
|
|
{
|
|
_sweep_up();
|
|
_sweep_down();
|
|
}
|
|
}
|