Added example for the DS18B20

components/ds18b20/examples/ds18b20-read/CMakeLists.txt

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+# The following five lines of boilerplate have to be in your project's
+# CMakeLists in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.16)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+set(COMPONENTS main)
+project(ds18b20-read)

components/ds18b20/examples/ds18b20-read/README.md

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+# DS18B20 sensor example
+
+This example shows how to use the DS18B20 component.
+
+## How to use the example
+
+### Hardware Required
+
+* An ESP development board
+* An DS18B20 sensor connected to GPIO 18. To use a different pin, modify `EXAMPLE_ONEWIRE_BUS_GPIO` in ds18b20-read.c.
+* An USB cable for power supply and programming
+
+### Example Output
+
+```bash
+...
+I (336) DS18B20: Device iterator created, start searching...
+I (456) DS18B20: Found a DS18B20[0], address: 990417C1D080FF28
+I (456) DS18B20: Searching done, 1 DS18B20 device(s) found
+I (456) main_task: Returned from app_main()
+I (1266) DS18B20: temperature read from DS18B20[0]: 27.94C
+I (4076) DS18B20: temperature read from DS18B20[0]: 27.81C
+I (6886) DS18B20: temperature read from DS18B20[0]: 27.75C
+I (9696) DS18B20: temperature read from DS18B20[0]: 27.69C
+I (12506) DS18B20: temperature read from DS18B20[0]: 27.62C
+I (15316) DS18B20: temperature read from DS18B20[0]: 27.56C
+I (18126) DS18B20: temperature read from DS18B20[0]: 27.44C
+I (20936) DS18B20: temperature read from DS18B20[0]: 27.38C
+I (23746) DS18B20: temperature read from DS18B20[0]: 27.31C
+...
+```

components/ds18b20/examples/ds18b20-read/main/CMakeLists.txt

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+idf_component_register(SRCS "ds18b20-read.c"
+                    INCLUDE_DIRS ".")

components/ds18b20/examples/ds18b20-read/main/ds18b20-read.c

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+/*
+ * SPDX-FileCopyrightText: 2022-2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+
+#include <stdio.h>
+#include "esp_log.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "ds18b20.h"
+#include "onewire_bus.h"
+
+#define EXAMPLE_ONEWIRE_BUS_GPIO    18
+#define EXAMPLE_ONEWIRE_MAX_DS18B20 2
+
+static int s_ds18b20_device_num = 0;
+static float s_temperature = 0.0;
+static ds18b20_device_handle_t s_ds18b20s[EXAMPLE_ONEWIRE_MAX_DS18B20];
+
+static const char *TAG = "DS18B20";
+
+static void sensor_detect(void)
+{
+    // install 1-wire bus
+    onewire_bus_handle_t bus = NULL;
+    onewire_bus_config_t bus_config = {
+        .bus_gpio_num = EXAMPLE_ONEWIRE_BUS_GPIO,
+    };
+    onewire_bus_rmt_config_t rmt_config = {
+        .max_rx_bytes = 10, // 1byte ROM command + 8byte ROM number + 1byte device command
+    };
+    ESP_ERROR_CHECK(onewire_new_bus_rmt(&bus_config, &rmt_config, &bus));
+
+    onewire_device_iter_handle_t iter = NULL;
+    onewire_device_t next_onewire_device;
+    esp_err_t search_result = ESP_OK;
+
+    // create 1-wire device iterator, which is used for device search
+    ESP_ERROR_CHECK(onewire_new_device_iter(bus, &iter));
+    ESP_LOGI(TAG, "Device iterator created, start searching...");
+    do {
+        search_result = onewire_device_iter_get_next(iter, &next_onewire_device);
+        if (search_result == ESP_OK) { // found a new device, let's check if we can upgrade it to a DS18B20
+            ds18b20_config_t ds_cfg = {};
+            // check if the device is a DS18B20, if so, return the ds18b20 handle
+            if (ds18b20_new_device(&next_onewire_device, &ds_cfg, &ds18b20s[ds18b20_device_num]) == ESP_OK) {
+                ESP_LOGI(TAG, "Found a DS18B20[%d], address: %016llX", ds18b20_device_num, next_onewire_device.address);
+                ds18b20_device_num++;
+            } else {
+                ESP_LOGI(TAG, "Found an unknown device, address: %016llX", next_onewire_device.address);
+            }
+        }
+    } while (search_result != ESP_ERR_NOT_FOUND);
+    ESP_ERROR_CHECK(onewire_del_device_iter(iter));
+    ESP_LOGI(TAG, "Searching done, %d DS18B20 device(s) found", ds18b20_device_num);
+}
+
+void readSensor(void)
+{
+    for (int i = 0; i < ds18b20_device_num; i ++) {
+        ESP_ERROR_CHECK(ds18b20_trigger_temperature_conversion(ds18b20s[i]));
+        ESP_ERROR_CHECK(ds18b20_get_temperature(ds18b20s[i], &temperature));
+        ESP_LOGI(TAG, "temperature read from DS18B20[%d]: %.2fC", i, temperature);
+    }
+}
+
+void readSensorTask(void *pvParameters)
+{
+    while (1) {
+        readSensor();
+        vTaskDelay(2000 / portTICK_PERIOD_MS);
+    }
+}
+
+void app_main(void)
+{
+    // Detect the DS18B20 sensor in the bus
+    sensorDetect();
+    // Start task to read the temperature from DS18B20 sensor
+    xTaskCreate(&readSensorTask, "readSensorTask", 4096, NULL, 5, NULL);
+}

components/ds18b20/examples/ds18b20-read/main/idf_component.yml

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+dependencies:
+  espressif/ds18b20:
+    version: "*"
+    override_path: '../../../'