Integrate JBD BMS telemetry into ESP32 status

firmware/esp32/xterra-controller/bms/bms.cpp

@@ -0,0 +1,204 @@
+#include "bms.h"
+
+#include <Arduino.h>
+#include <NimBLEDevice.h>
+
+static const char* BMS_ADDRESS = "a5:c2:37:2c:05:dc";
+static const char* BMS_SERVICE_UUID = "ff00";
+static const char* BMS_NOTIFY_UUID = "ff01";
+static const char* BMS_WRITE_UUID = "ff02";
+
+static NimBLEClient* client = nullptr;
+static NimBLERemoteCharacteristic* notifyChar = nullptr;
+static NimBLERemoteCharacteristic* writeChar = nullptr;
+
+static uint8_t responseBuffer[128];
+static size_t responseLength = 0;
+static bool responseReady = false;
+
+static unsigned long lastReadAttempt = 0;
+static const unsigned long READ_INTERVAL_MS = 5000;
+
+BmsData bmsData;
+
+static uint8_t JBD_STATUS_REQUEST[] = {
+    0xDD, 0xA5, 0x03, 0x00, 0xFF, 0xFD, 0x77
+};
+
+static uint16_t readU16(const uint8_t* data, int index) {
+    return ((uint16_t)data[index] << 8) | data[index + 1];
+}
+
+static int16_t readS16(const uint8_t* data, int index) {
+    return (int16_t)readU16(data, index);
+}
+
+static void resetResponseBuffer() {
+    responseLength = 0;
+    responseReady = false;
+}
+
+static void handleNotify(
+    NimBLERemoteCharacteristic* characteristic,
+    uint8_t* data,
+    size_t length,
+    bool isNotify
+) {
+    if (responseLength + length > sizeof(responseBuffer)) {
+        resetResponseBuffer();
+        return;
+    }
+
+    memcpy(responseBuffer + responseLength, data, length);
+    responseLength += length;
+
+    if (responseLength > 0 && responseBuffer[responseLength - 1] == 0x77) {
+        responseReady = true;
+    }
+}
+
+static bool connectBms() {
+    if (client && client->isConnected()) {
+        return true;
+    }
+
+    Serial.println("BMS: Connecting...");
+
+    NimBLEAddress address(std::string(BMS_ADDRESS), BLE_ADDR_PUBLIC);
+
+    client = NimBLEDevice::createClient();
+
+    if (!client->connect(address)) {
+        Serial.println("BMS: Connect failed");
+        bmsData.connected = false;
+        return false;
+    }
+
+    NimBLERemoteService* service = client->getService(BMS_SERVICE_UUID);
+    if (!service) {
+        Serial.println("BMS: Service ff00 not found");
+        client->disconnect();
+        bmsData.connected = false;
+        return false;
+    }
+
+    notifyChar = service->getCharacteristic(BMS_NOTIFY_UUID);
+    writeChar = service->getCharacteristic(BMS_WRITE_UUID);
+
+    if (!notifyChar || !writeChar) {
+        Serial.println("BMS: Characteristics not found");
+        client->disconnect();
+        bmsData.connected = false;
+        return false;
+    }
+
+    if (!notifyChar->subscribe(true, handleNotify)) {
+        Serial.println("BMS: Notify subscribe failed");
+        client->disconnect();
+        bmsData.connected = false;
+        return false;
+    }
+
+    Serial.println("BMS: Connected");
+    bmsData.connected = true;
+    return true;
+}
+
+static bool parseBasicInfo() {
+    if (responseLength < 40) {
+        Serial.println("BMS: Response too short");
+        return false;
+    }
+
+    if (responseBuffer[0] != 0xDD || responseBuffer[1] != 0x03) {
+        Serial.println("BMS: Unexpected response header");
+        return false;
+    }
+
+    uint16_t voltageRaw = readU16(responseBuffer, 4);
+    int16_t currentRaw = readS16(responseBuffer, 6);
+    uint16_t remainingRaw = readU16(responseBuffer, 8);
+    uint16_t capacityRaw = readU16(responseBuffer, 10);
+    uint16_t cyclesRaw = readU16(responseBuffer, 12);
+
+    uint8_t socRaw = responseBuffer[23];
+    uint8_t mosTempAndCellOffset = 24;
+
+    uint8_t cellCount = responseBuffer[mosTempAndCellOffset + 1];
+    uint8_t ntcCount = responseBuffer[mosTempAndCellOffset + 2];
+
+    int tempOffset = mosTempAndCellOffset + 3;
+    float tempF = 0;
+
+    if (ntcCount > 0 && responseLength > (size_t)(tempOffset + 1)) {
+        uint16_t tempRaw = readU16(responseBuffer, tempOffset);
+        float tempC = (tempRaw - 2731) / 10.0;
+        tempF = tempC * 9.0 / 5.0 + 32.0;
+    }
+
+    bmsData.voltage = voltageRaw / 100.0;
+    bmsData.current = currentRaw / 100.0;
+    bmsData.remainingAh = remainingRaw / 100.0;
+    bmsData.capacityAh = capacityRaw / 100.0;
+    bmsData.cycleCount = cyclesRaw;
+    bmsData.soc = socRaw;
+    bmsData.cellCount = cellCount;
+    bmsData.ntcCount = ntcCount;
+    bmsData.temperatureF = tempF;
+    bmsData.valid = true;
+
+    Serial.print("BMS: SOC ");
+    Serial.print(bmsData.soc);
+    Serial.print("%, V ");
+    Serial.print(bmsData.voltage);
+    Serial.print(", A ");
+    Serial.print(bmsData.current);
+    Serial.print(", Ah ");
+    Serial.println(bmsData.remainingAh);
+
+    return true;
+}
+
+void initBms() {
+    NimBLEDevice::init("XterraESP32");
+    NimBLEDevice::setPower(ESP_PWR_LVL_P9);
+    resetResponseBuffer();
+}
+
+void updateBms() {
+    if (millis() - lastReadAttempt < READ_INTERVAL_MS) {
+        return;
+    }
+
+    lastReadAttempt = millis();
+
+    if (!connectBms()) {
+        return;
+    }
+
+    resetResponseBuffer();
+
+    bool ok = writeChar->writeValue(
+        JBD_STATUS_REQUEST,
+        sizeof(JBD_STATUS_REQUEST),
+        false
+    );
+
+    if (!ok) {
+        Serial.println("BMS: Write failed");
+        bmsData.connected = false;
+        return;
+    }
+
+    unsigned long start = millis();
+    while (!responseReady && millis() - start < 2000) {
+        delay(10);
+    }
+
+    if (!responseReady) {
+        Serial.println("BMS: Read timeout");
+        return;
+    }
+
+    parseBasicInfo();
+}

firmware/esp32/xterra-controller/bms/bms.h

@@ -0,0 +1,22 @@
+#pragma once
+
+struct BmsData {
+    bool connected = false;
+    bool valid = false;
+
+    float soc = 0;
+    float voltage = 0;
+    float current = 0;
+    float remainingAh = 0;
+    float capacityAh = 0;
+    float temperatureF = 0;
+
+    int cycleCount = 0;
+    int cellCount = 0;
+    int ntcCount = 0;
+};
+
+extern BmsData bmsData;
+
+void initBms();
+void updateBms();

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

@@ -6,30 +6,59 @@
 #include "protocol.h"
 #include "relays.h"
 #include "sensors.h"
+#include "bms/bms.h"
 
 WebServer server(80);
 HardwareSerial DashboardSerial(2);
 
 String uartLineBuffer;
 
-float batterySOC = 82.0;
-float batteryVoltage = 13.2;
-float batteryCurrent = -6.4;
-float batteryRemainingAh = 82.0;
-float batteryRuntimeHours = 12.0;
-float batteryTemp = 76.0;
+float calculateRuntimeHours() {
+    if (!bmsData.valid || bmsData.current >= 0) {
+        return 0;
+    }
+
+    float dischargeAmps = -bmsData.current;
+    if (dischargeAmps <= 0.1) {
+        return 0;
+    }
+
+    return bmsData.remainingAh / dischargeAmps;
+}
 
 void buildStatusDocument(JsonDocument& doc) {
     doc["type"] = MSG_STATUS_RESPONSE;
     doc["timestamp"] = millis();
 
     JsonObject battery = doc.createNestedObject("battery");
-    battery["soc"] = batterySOC;
-    battery["voltage"] = batteryVoltage;
-    battery["current"] = batteryCurrent;
-    battery["remaining_ah"] = batteryRemainingAh;
-    battery["runtime_hours"] = batteryRuntimeHours;
-    battery["temperature_f"] = batteryTemp;
+
+    if (bmsData.valid) {
+        battery["source"] = "jbd_bms";
+        battery["connected"] = bmsData.connected;
+        battery["soc"] = bmsData.soc;
+        battery["voltage"] = bmsData.voltage;
+        battery["current"] = bmsData.current;
+        battery["remaining_ah"] = bmsData.remainingAh;
+        battery["capacity_ah"] = bmsData.capacityAh;
+        battery["runtime_hours"] = calculateRuntimeHours();
+        battery["temperature_f"] = bmsData.temperatureF;
+        battery["cycle_count"] = bmsData.cycleCount;
+        battery["cell_count"] = bmsData.cellCount;
+        battery["ntc_count"] = bmsData.ntcCount;
+    } else {
+        battery["source"] = "placeholder";
+        battery["connected"] = false;
+        battery["soc"] = 0;
+        battery["voltage"] = 0;
+        battery["current"] = 0;
+        battery["remaining_ah"] = 0;
+        battery["capacity_ah"] = 150;
+        battery["runtime_hours"] = 0;
+        battery["temperature_f"] = 0;
+        battery["cycle_count"] = 0;
+        battery["cell_count"] = 0;
+        battery["ntc_count"] = 0;
+    }
 
     JsonObject temps = doc.createNestedObject("temps");
 
@@ -237,6 +266,7 @@ void setup() {
 
     initRelays();
     initSensors();
+    initBms();
 
     WiFi.mode(WIFI_AP);
 
@@ -264,6 +294,7 @@ void setup() {
 
 void loop() {
     server.handleClient();
+    updateBms();
     pollDashboardUart();
 
     static unsigned long lastSensorUpdate = 0;