mirror of
https://github.com/mytechnotalent/Embedded-Hacking.git
synced 2026-05-19 14:28:06 +02:00
Kevin Thomas
120 lines
3.4 KiB
C
120 lines
3.4 KiB
C
/**
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* @file main.c
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* @brief ADC demonstration: potentiometer voltage and chip temperature.
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* @author Kevin Thomas
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* @date 2026
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*
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* Demonstrates 12-bit ADC using the bare-metal ADC driver. Reads
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* ADC channel 0 (GPIO26) and reports the voltage in millivolts
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* alongside the on-chip temperature sensor reading every 500 ms
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* over UART.
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*
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* Wiring:
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* GPIO0 -> UART TX (USB-to-UART adapter RX)
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* GPIO1 -> UART RX (USB-to-UART adapter TX)
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* GPIO26 -> Wiper of a 10 kohm potentiometer
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* 3.3V -> One end of the potentiometer
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* GND -> Other end of the potentiometer
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*
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* MIT License
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*
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* Copyright (c) 2026 Kevin Thomas
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#include "rp2350_adc.h"
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#include "rp2350_uart.h"
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#include "rp2350_xosc.h"
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#include "rp2350_delay.h"
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/** @brief Delay between ADC samples in milliseconds */
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#define SAMPLE_DELAY_MS 500
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/**
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* @brief Reverse a character buffer in place.
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* @param buf pointer to the buffer
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* @param len number of characters to reverse
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* @retval None
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*/
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static void reverse(char *buf, uint8_t len)
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{
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for (uint8_t i = 0; i < len / 2; i++)
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{
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char tmp = buf[i];
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buf[i] = buf[len - 1 - i];
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buf[len - 1 - i] = tmp;
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}
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}
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/**
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* @brief Print an unsigned 32-bit integer as a decimal string over UART.
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* @param val value to print
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* @retval None
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*/
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static void print_uint32(uint32_t val)
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{
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char buf[11];
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uint8_t len = 0;
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do { buf[len++] = (char)('0' + val % 10); val /= 10; } while (val > 0);
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reverse(buf, len);
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buf[len] = '\0';
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uart_puts(buf);
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}
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/**
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* @brief Print a signed temperature in tenths of degrees as XX.X over UART.
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* @param tenths temperature in tenths of degrees Celsius
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* @retval None
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*/
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static void print_temp(int32_t tenths)
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{
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if (tenths < 0) { uart_puts("-"); tenths = -tenths; }
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print_uint32((uint32_t)(tenths / 10));
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char frac[2] = { (char)('0' + tenths % 10), '\0' };
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uart_puts(".");
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uart_puts(frac);
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}
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/**
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* @brief Print ADC voltage and chip temperature readings over UART.
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* @retval None
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*/
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static void print_readings(void)
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{
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uint32_t mv = adc_read_mv();
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int32_t temp = adc_read_temp_tenths();
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uart_puts("ADC0: ");
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print_uint32(mv);
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uart_puts(" mV | Chip temp: ");
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print_temp(temp);
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uart_puts(" C\r\n");
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}
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int main(void)
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{
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xosc_enable_adc_clk();
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adc_release_reset();
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adc_init();
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while (1)
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{
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print_readings();
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delay_ms(SAMPLE_DELAY_MS);
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}
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}
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