mirror of
https://github.com/mytechnotalent/Embedded-Hacking.git
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Kevin Thomas
80 lines
2.8 KiB
C
80 lines
2.8 KiB
C
/**
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* @file 0x09_dht11.c
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* @brief DHT11 temperature and humidity sensor driver for the Raspberry Pi Pico 2
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* @author Kevin Thomas
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* @date 2025
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*
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* MIT License
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*
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* Copyright (c) 2025 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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* -----------------------------------------------------------------------------
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*
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* This driver demonstrates how to read temperature and humidity from a DHT11
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* sensor using the dht11.c/dht11.h driver. The sensor is polled every 2
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* seconds (the minimum safe interval for the DHT11) and the results are
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* printed over UART. A failed read is reported so wiring issues are visible.
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*
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* Wiring:
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* GPIO4 -> DHT11 DATA pin (10 kohm pull-up to 3.3 V recommended)
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* 3.3V -> DHT11 VCC
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* GND -> DHT11 GND
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*/
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#include <stdio.h>
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#include "pico/stdlib.h"
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#include "dht11.h"
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#define DHT11_GPIO 4
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/**
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* @brief Read the DHT11 sensor and print the result over UART
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*
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* Attempts a single read. On success prints humidity and temperature;
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* on failure prints a wiring-check message. Waits 2 s before returning
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* to respect the DHT11 minimum polling interval.
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*/
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static void _print_reading(void) {
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float humidity = 0.0f;
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float temperature = 0.0f;
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if (dht11_read(&humidity, &temperature))
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printf("Humidity: %.1f%% Temperature: %.1f C\r\n", humidity, temperature);
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else
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printf("DHT11 read failed - check wiring on GPIO %d\r\n", DHT11_GPIO);
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sleep_ms(2000);
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}
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/**
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* @brief Application entry point for the DHT11 sensor demo
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*
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* Initializes the DHT11 on GPIO4 and continuously reads temperature
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* and humidity, printing results over UART every 2 seconds.
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*
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* @return int Does not return
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*/
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int main(void) {
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stdio_init_all();
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dht11_init(DHT11_GPIO);
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printf("DHT11 driver initialized on GPIO %d\r\n", DHT11_GPIO);
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while (true)
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_print_reading();
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}
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