Add support for DS18B20 sensors (#907)

Add support for DS18B20 sensors.

This supports multiple sensors chained onto the same pin.

platformio.ini

@@ -106,6 +106,10 @@ lib_deps =
   beegee-tokyo/DHT sensor library for ESPx@^1.18
   sparkfun/SparkFun SGP30 Arduino Library@^1.0.5
   sensirion/arduino-sht@^1.2.2
+  paulstoffregen/OneWire@^2.3.7
+  milesburton/DallasTemperature@^3.11.0
+
+
 
 [env:esp32]
 extends = esp32

src/DS18B20.cpp

@@ -0,0 +1,163 @@
+#ifdef SENSORS
+#include "DS18B20.h"
+
+#include "globals.h"
+#include "mqtt.h"
+#include "defaults.h"
+#include <AsyncWiFiSettings.h>
+#include <AsyncMqttClient.h>
+#include "string_utils.h"
+
+#include <DallasTemperature.h>
+#include <OneWire.h>
+#include <Ticker.h>
+
+
+namespace DS18B20 
+{
+    int ds18b20Pin = -1;
+    float dsTempOffset;
+    int numSensors = 0;
+
+    /** Initialize onewire and Dallas Temperature*/
+    OneWire oneWire;
+    DallasTemperature sensors;
+
+    /** Task handle for the light value read task */
+    TaskHandle_t DSTempTaskHandle = NULL;
+
+    /** Ticker for temperature reading */
+    Ticker tempTicker;
+
+    /** Flags for temperature readings finished */
+    bool gotNewTemperature = false;
+
+    /* Flag if main loop is running */
+    bool dsTasksEnabled = false;
+
+    /* update every 10 seconds */
+    int dsUpdateTime = 10;
+
+    /**
+     * Task to reads temperature from DS18B20 sensor
+     * @param pvParameters
+     *		pointer to task parameters
+     */
+    void tempTask(void *pvParameters)
+    {
+        while (1) // tempTask loop
+        {
+            if (dsTasksEnabled && !gotNewTemperature)
+            {
+                // Read temperature only if old data was processed already
+                sensors.requestTemperatures();
+                gotNewTemperature = true;
+            }
+            vTaskSuspend(NULL);
+        }
+    }
+
+    /**
+     * triggerGetTemp
+     * Sets flag dhtUpdated to true for handling in loop()
+     * called by Ticker tempTicker
+     */
+    void triggerGetTemp()
+    {
+        if (DSTempTaskHandle != NULL)
+        {
+            xTaskResumeFromISR(DSTempTaskHandle);
+        }
+    }
+
+    void Setup()
+    {
+        if (ds18b20Pin>=0) {
+            oneWire.begin(ds18b20Pin);
+            sensors.setOneWire(&oneWire);
+            sensors.begin();
+            //Need to begin twice for some reason to get the sensors to start
+            sensors.begin();
+
+            numSensors = sensors.getDeviceCount();
+
+            // Start task to get temperature
+            xTaskCreatePinnedToCore(
+                    tempTask,           /* Function to implement the task */
+                    "DS",              /* Name of the task */
+                    1024,               /* Stack size in words */
+                    NULL,               /* Task input parameter */
+                    5,                  /* Priority of the task */
+                    &DSTempTaskHandle, /* Task handle. */
+                    1);                 /* Core where the task should run */
+
+            if (DSTempTaskHandle == NULL)
+            {
+                Serial.println("[ERROR] Failed to start task for temperature update");
+            }
+            else
+            {
+                // Start update of environment data every 10 seconds
+                tempTicker.attach(dsUpdateTime, triggerGetTemp);
+            }
+
+            // Signal end of setup() to tasks
+            dsTasksEnabled = true;
+        }
+    }
+
+    void ConnectToWifi()
+    {
+        AsyncWiFiSettings.html("h4", "DS18B20:");
+        ds18b20Pin = AsyncWiFiSettings.integer("ds18b20_pin", -1, "DS18B20 sensor pin (-1 for disable)");
+        dsTempOffset = AsyncWiFiSettings.floating("dsTemp_offset", -40, 125, 0.0, "DS18B20 temperature offset");
+    }
+
+    void SerialReport()
+    {
+        if (ds18b20Pin<0) return;
+        Serial.print("DS18B20 Sensor: ");
+        Serial.println((ds18b20Pin>=0 ? "pin " + String(ds18b20Pin) : "disabled").c_str());
+        Serial.print("DS18B20 Offset:   ");
+        Serial.println(dsTempOffset);
+    }
+
+    void Loop()
+    {
+        if (ds18b20Pin<0) return;
+
+        if (gotNewTemperature)
+        {
+            for (int i = 0; i < numSensors; i++){
+                float temperature = sensors.getTempCByIndex(i) + dsTempOffset;
+                Serial.println("DS18B20 Temp_"+ String(i+1) + ": " + String(temperature, 1) + "'C");
+
+                pub((roomsTopic + "/ds18b20_temperature_" + String(i+1)).c_str(), 0, 1, String(temperature, 1).c_str());
+            }
+
+            gotNewTemperature = false;
+        }
+    }
+
+    bool SendDiscovery()
+    {
+        if (ds18b20Pin<0) return true;
+        bool returnVal = true;
+
+        for (int i = 0; i < numSensors; i++){
+            returnVal = sendSensorDiscovery("DS18B20 Temperature " + String(i+1), EC_NONE, "temperature", "°C") && returnVal;
+        }
+        return returnVal;
+    }
+
+    bool Command(String& command, String& pay)
+    {
+        return false;
+    }
+
+    bool SendOnline()
+    {
+        return true;
+    }
+}
+#endif

src/DS18B20.h

@@ -0,0 +1,15 @@
+#pragma once
+#ifdef SENSORS
+#include <ArduinoJson.h>
+
+namespace DS18B20 
+{
+    void Setup();
+    void ConnectToWifi();
+    void SerialReport();
+    void Loop();
+    bool SendDiscovery();
+    bool SendOnline();
+    bool Command(String& command, String& pay);
+}
+#endif

src/main.cpp

@@ -54,6 +54,7 @@ bool sendTelemetry(unsigned int totalSeen, unsigned int totalFpSeen, int unsigne
             && TSL2561::SendDiscovery()
             && SensirionSGP30::SendDiscovery()
             && HX711::SendDiscovery()
+            && DS18B20::SendDiscovery()
 #endif
         ) {
             sentDiscovery = true;
@@ -188,6 +189,7 @@ void setupNetwork() {
     TSL2561::ConnectToWifi();
     SensirionSGP30::ConnectToWifi();
     HX711::ConnectToWifi();
+    DS18B20::ConnectToWifi();
 
 #endif
 
@@ -248,6 +250,7 @@ void setupNetwork() {
     TSL2561::SerialReport();
     SensirionSGP30::SerialReport();
     HX711::SerialReport();
+    DS18B20::SerialReport();
 
 #endif
     Serial.print("Query:        ");
@@ -527,6 +530,7 @@ void setup() {
     TSL2561::Setup();
     SensirionSGP30::Setup();
     HX711::Setup();
+    DS18B20::Setup();
 #endif
     xTaskCreatePinnedToCore(scanTask, "scanTask", SCAN_TASK_STACK_SIZE, nullptr, 1, &scanTaskHandle, CONFIG_BT_NIMBLE_PINNED_TO_CORE);
     reportSetup();
@@ -561,5 +565,6 @@ void loop() {
     TSL2561::Loop();
     SensirionSGP30::Loop();
     HX711::Loop();
+    DS18B20::Loop();
 #endif
 }

src/main.h

@@ -41,6 +41,7 @@
 #include "SHT.h"
 #include "SensirionSGP30.h"
 #include "TSL2561.h"
+#include "DS18B20.h"
 #endif
 
 TimerHandle_t reconnectTimer;