Add DS18B20 temperature sensor support

firmware/esp32/xterra-controller/sensors.cpp

@@ -1,10 +1,87 @@
+#include <Arduino.h>
+#include <OneWire.h>
+#include <DallasTemperature.h>
+
+#include "config.h"
 #include "sensors.h"
 
 SensorData sensors;
 
+OneWire oneWire(ONEWIRE_PIN);
+DallasTemperature ds18b20(&oneWire);
+
+DeviceAddress sensorAddresses[4];
+int sensorCount = 0;
+
+float cToF(float c) {
+    return (c * 9.0 / 5.0) + 32.0;
+}
+
+bool validTempC(float tempC) {
+    return tempC != DEVICE_DISCONNECTED_C && tempC > -55 && tempC < 125;
+}
+
+void printAddress(DeviceAddress address) {
+    for (uint8_t i = 0; i < 8; i++) {
+        if (address[i] < 16) Serial.print("0");
+        Serial.print(address[i], HEX);
+        if (i < 7) Serial.print(":");
+    }
+}
+
+void printSensorAddresses() {
+    Serial.println("DS18B20 Sensors Found:");
+
+    for (int i = 0; i < sensorCount; i++) {
+        Serial.print("Sensor ");
+        Serial.print(i);
+        Serial.print(": ");
+        printAddress(sensorAddresses[i]);
+        Serial.println();
+    }
+
+    if (sensorCount == 0) {
+        Serial.println("No DS18B20 sensors found.");
+    }
+}
+
 void initSensors() {
+    ds18b20.begin();
+    sensorCount = ds18b20.getDeviceCount();
+
+    if (sensorCount > 4) {
+        sensorCount = 4;
+    }
+
+    for (int i = 0; i < sensorCount; i++) {
+        ds18b20.getAddress(sensorAddresses[i], i);
+    }
+
+    printSensorAddresses();
 }
 
 void updateSensors() {
-    // Placeholder until DS18B20 support is added
+    ds18b20.requestTemperatures();
+
+    float tempsF[4] = {-127, -127, -127, -127};
+    bool online[4] = {false, false, false, false};
+
+    for (int i = 0; i < sensorCount; i++) {
+        float tempC = ds18b20.getTempC(sensorAddresses[i]);
+
+        if (validTempC(tempC)) {
+            tempsF[i] = cToF(tempC);
+            online[i] = true;
+        }
+    }
+
+    sensors.fridgeZone1 = tempsF[0];
+    sensors.fridgeZone2 = tempsF[1];
+    sensors.rearSeat = tempsF[2];
+    sensors.outsideAir = tempsF[3];
+
+    sensors.fridgeZone1Online = online[0];
+    sensors.fridgeZone2Online = online[1];
+    sensors.rearSeatOnline = online[2];
+    sensors.outsideAirOnline = online[3];
 }

firmware/esp32/xterra-controller/sensors.h

@@ -1,13 +1,19 @@
 #pragma once
 
 struct SensorData {
-    float fridgeZone1 = 36.0;
-    float fridgeZone2 = 12.0;
-    float rearSeat = 78.0;
-    float outsideAir = 88.0;
+    float fridgeZone1 = -127.0;
+    float fridgeZone2 = -127.0;
+    float rearSeat = -127.0;
+    float outsideAir = -127.0;
+
+    bool fridgeZone1Online = false;
+    bool fridgeZone2Online = false;
+    bool rearSeatOnline = false;
+    bool outsideAirOnline = false;
 };
 
 extern SensorData sensors;
 
 void initSensors();
 void updateSensors();
+void printSensorAddresses();

firmware/esp32/xterra-controller/xterra-controller.ino

@@ -30,10 +30,16 @@ void handleStatus() {
     battery["temperature_f"] = batteryTemp;
 
     JsonObject temps = doc.createNestedObject("temps");
-    temps["fridge_zone_1"] = sensors.fridgeZone1;
-    temps["fridge_zone_2"] = sensors.fridgeZone2;
-    temps["rear_seat"] = sensors.rearSeat;
-    temps["outside"] = sensors.outsideAir;
+    temps["fridge_zone_1"] = sensors.fridgeZone1Online ? sensors.fridgeZone1 : nullptr;
+    temps["fridge_zone_2"] = sensors.fridgeZone2Online ? sensors.fridgeZone2 : nullptr;
+    temps["rear_seat"] = sensors.rearSeatOnline ? sensors.rearSeat : nullptr;
+    temps["outside"] = sensors.outsideAirOnline ? sensors.outsideAir : nullptr;
+
+    JsonObject sensorHealth = doc.createNestedObject("sensor_health");
+    sensorHealth["fridge_zone_1"] = sensors.fridgeZone1Online;
+    sensorHealth["fridge_zone_2"] = sensors.fridgeZone2Online;
+    sensorHealth["rear_seat"] = sensors.rearSeatOnline;
+    sensorHealth["outside"] = sensors.outsideAirOnline;
 
     JsonObject relayObj = doc.createNestedObject("relays");
     relayObj["starlink"] = relays.starlink;