Files
Embedded-Hacking/0x0008_uninitialized-variables-b/0x0008_uninitialized-variables-b.c
T
Kevin Thomas 6a9090915b Initial commit
2026-07-06 21:23:12 -04:00

81 lines
2.6 KiB
C

/**
* @file 0x0008_uninitialized-variables-b.c
* @brief Blink LED using gpioc coprocessor bit-level functions
* @author Kevin Thomas
* @date 2025
*
* MIT License
*
* Copyright (c) 2025 Kevin Thomas
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* -----------------------------------------------------------------------------
*
* Blinks an LED on GPIO16 using the RP2350 gpioc coprocessor bit-level
* functions (gpioc_bit_oe_put / gpioc_bit_out_put) instead of the standard
* gpio_init / gpio_put SDK calls.
*
* Wiring:
* GPIO16 -> LED anode (with current-limiting resistor to GND)
*/
#include <stdio.h>
#include "pico/stdlib.h"
/** @brief GPIO pin number for the LED */
#define LED_PIN 16
/**
* @brief Initialize GPIO16 for output using coprocessor bit functions
*
* @details Configures the pad for SIO, sets direction to input first,
* clears the output, selects SIO function, then enables output.
*
* @retval None
*/
static void gpio_coprocessor_init(void) {
gpio_set_dir(LED_PIN, GPIO_IN);
gpio_put(LED_PIN, 0);
gpio_set_function(LED_PIN, GPIO_FUNC_SIO);
gpioc_bit_oe_put(LED_PIN, GPIO_OUT);
}
/**
* @brief Blink LED using coprocessor bit output functions
*
* @details Toggles the LED on and off with 500ms delays using
* gpioc_bit_out_put and sleep_us.
*
* @retval None
*/
static void blink_cycle(void) {
gpioc_bit_out_put(LED_PIN, 1);
sleep_us(500 * 1000ull);
gpioc_bit_out_put(LED_PIN, 0);
sleep_us(500 * 1000ull);
}
int main(void) {
gpio_coprocessor_init();
while (true) {
blink_cycle();
}
}