Feature/mqtt on main

Software/Software.ino

@@ -148,6 +148,9 @@ void loop() {
 #ifdef WEBSERVER
   // Over-the-air updates by ElegantOTA
   ElegantOTA.loop();
+#ifdef MQTT
+  mqtt_loop();
+#endif
 #endif
 
   // Input

Software/USER_SETTINGS.cpp

@@ -15,6 +15,12 @@ volatile uint16_t MAXCHARGEAMP =
 volatile uint16_t MAXDISCHARGEAMP =
     300;  //30.0A , BYD CAN specific setting, Max discharge speed in Amp (Some inverters needs to be artificially limited)
 
+// MQTT
+// For more detailed settings, see mqtt.h
+#ifdef MQTT
+const char* mqtt_user = "REDACTED";
+const char* mqtt_password = "REDACTED";
+#endif  // USE_MQTT
 /* Charger settings */
 volatile float CHARGER_SET_HV = 384;      // Reasonably appropriate 4.0v per cell charging of a 96s pack
 volatile float CHARGER_MAX_HV = 420;      // Max permissible output (VDC) of charger

Software/USER_SETTINGS.h

@@ -21,23 +21,24 @@
 
 /* Select inverter communication protocol. See Wiki for which to use with your inverter: https://github.com/dalathegreat/BYD-Battery-Emulator-For-Gen24/wiki */
 //#define BYD_CAN          //Enable this line to emulate a "BYD Battery-Box Premium HVS" over CAN Bus
-//#define BYD_MODBUS       //Enable this line to emulate a "BYD 11kWh HVM battery" over Modbus RTU
+//#define BYD_MODBUS  //Enable this line to emulate a "BYD 11kWh HVM battery" over Modbus RTU
 //#define LUNA2000_MODBUS  //Enable this line to emulate a "Luna2000 battery" over Modbus RTU
 //#define PYLON_CAN        //Enable this line to emulate a "Pylontech battery" over CAN bus
 //#define SMA_CAN          //Enable this line to emulate a "BYD Battery-Box H 8.9kWh, 7 mod" over CAN bus
 //#define SOFAR_CAN        //Enable this line to emulate a "Sofar Energy Storage Inverter High Voltage BMS General Protocol (Extended Frame)" over CAN bus
 //#define SOLAX_CAN        //Enable this line to emulate a "SolaX Triple Power LFP" over CAN bus
 
 /* Other options */
-#define DEBUG_VIA_USB  //Enable this line to have the USB port output serial diagnostic data while program runs
-//define INTERLOCK_REQUIRED //Nissan LEAF specific setting, if enabled requires both high voltage conenctors to be seated before starting
+//#define DEBUG_VIA_USB  //Enable this line to have the USB port output serial diagnostic data while program runs
+//#define INTERLOCK_REQUIRED  //Nissan LEAF specific setting, if enabled requires both high voltage conenctors to be seated before starting
 //#define CONTACTOR_CONTROL     //Enable this line to have pins 25,32,33 handle automatic precharge/contactor+/contactor- closing sequence
 //#define PWM_CONTACTOR_CONTROL //Enable this line to use PWM logic for contactors, which lower power consumption and heat generation
 //#define DUAL_CAN              //Enable this line to activate an isolated secondary CAN Bus using add-on MCP2515 controller (Needed for FoxESS inverters)
 //#define SERIAL_LINK_RECEIVER  //Enable this line to receive battery data over RS485 pins from another Lilygo (This LilyGo interfaces with inverter)
 //#define SERIAL_LINK_TRANSMITTER  //Enable this line to send battery data over RS485 pins to another Lilygo (This LilyGo interfaces with battery)
-#define WEBSERVER  //Enable this line to enable WiFi, and to run the webserver. See USER_SETTINGS.cpp for the Wifi settings.
-#define LOAD_SAVED_SETTINGS_ON_BOOT  //Enable this line to read settings stored via the webserver on boot
+//#define WEBSERVER  //Enable this line to enable WiFi, and to run the webserver. See USER_SETTINGS.cpp for the Wifi settings.
+//#define MQTT       // Enable this line to enable MQTT
+//#define LOAD_SAVED_SETTINGS_ON_BOOT  //Enable this line to read settings stored via the webserver on boot
 
 /* Select charger used (Optional) */
 //#define CHEVYVOLT_CHARGER //Enable this line to control a Chevrolet Volt charger connected to battery - for example, when generator charging or using an inverter without a charging function.

Software/src/battery/NISSAN-LEAF-BATTERY.cpp

@@ -1,4 +1,7 @@
 #include "NISSAN-LEAF-BATTERY.h"
+#ifdef MQTT
+#include "../devboard/mqtt/mqtt.h"
+#endif
 #include "../lib/miwagner-ESP32-Arduino-CAN/CAN_config.h"
 #include "../lib/miwagner-ESP32-Arduino-CAN/ESP32CAN.h"
 
@@ -17,6 +20,10 @@ static uint8_t mprun10r = 0;                 //counter 0-20 for 0x1F2 message
 static uint8_t mprun10 = 0;                  //counter 0-3
 static uint8_t mprun100 = 0;                 //counter 0-3
 
+#ifdef MQTT
+bool mqtt_first_transmission = true;
+#endif
+
 CAN_frame_t LEAF_1F2 = {.FIR = {.B =
                                     {
                                         .DLC = 8,
@@ -155,6 +162,10 @@ static uint16_t temp_raw_min = 0;
 static int16_t temp_polled_max = 0;
 static int16_t temp_polled_min = 0;
 
+#ifdef MQTT
+void publish_data(void);
+#endif
+
 void print_with_units(char* header, int value, char* units) {
   Serial.print(header);
   Serial.print(value);
@@ -402,6 +413,9 @@ void update_values_leaf_battery() { /* This function maps all the values fetched
   }
 
 #endif
+#ifdef MQTT
+  publish_data();
+#endif
 }
 
 void receive_can_leaf_battery(CAN_frame_t rx_frame) {
@@ -917,3 +931,70 @@ uint16_t Temp_fromRAW_to_F(uint16_t temperature) {  //This function feels horrib
   }
   return static_cast<uint16_t>(1094 + (309 - temperature) * 2.5714285714285715);
 }
+
+#ifdef MQTT
+void publish_data(void) {
+
+  // At startup, re-post the discovery message for home assistant
+  if (mqtt_first_transmission == true) {
+    mqtt_first_transmission = false;
+
+    // Base topic for any cell voltage "sensor"
+    // TODO: make the discovery topic configurable centrally... but this is fine
+    String topic = "homeassistant/sensor/battery-emulator/cell_voltage";
+    for (int i = 0; i < 96; i++) {
+      // Build JSON message with device configuration for each cell voltage
+      // Probably shouldn't be BatteryEmulator here, instead "LeafBattery"
+      // or similar but hey, it works.
+      // mqtt_msg is a global buffer, should be fine since we run too much
+      // in a single thread :)
+      snprintf(mqtt_msg, sizeof(mqtt_msg),
+               "{"
+               "\"device\": {"
+               "\"identifiers\": ["
+               "\"battery-emulator\""
+               "],"
+               "\"manufacturer\": \"DalaTech\","
+               "\"model\": \"BatteryEmulator\","
+               "\"name\": \"BatteryEmulator\""
+               "},"
+               "\"device_class\": \"voltage\","
+               "\"enabled_by_default\": true,"
+               "\"object_id\": \"sensor_battery_voltage_cell%d\","
+               "\"origin\": {"
+               "\"name\": \"BatteryEmulator\","
+               "\"sw\": \"4.4.0-mqtt\","
+               "\"url\": \"https://github.com/dalathegreat/Battery-Emulator\""
+               "},"
+               "\"state_class\": \"measurement\","
+               "\"name\": \"Battery Cell Voltage %d\","
+               "\"state_topic\": \"battery/spec_data\","
+               "\"unique_id\": \"battery-emulator_battery_voltage_cell%d\","
+               "\"unit_of_measurement\": \"V\","
+               "\"value_template\": \"{{ value_json.cell_voltages[%d] }}\""
+               "}",
+               i + 1, i + 1, i + 1, i);
+      // End each discovery topic with cell number and '/config'
+      String cell_topic = topic + String(i + 1) + "/config";
+      mqtt_publish_retain(cell_topic.c_str());
+    }
+  }
+
+  // Every 5-ish seconds, build the JSON payload for the state topic. This requires
+  // some annoying formatting due to C++ not having nice Python-like string formatting.
+  // msg_length is a cumulative variable to track start position (param 1) and for
+  // modifying the maxiumum amount of characters to write (param 2). The third parameter
+  // is the string content
+  size_t msg_length = snprintf(mqtt_msg, sizeof(mqtt_msg), "{\n\"cell_voltages\":[");
+  for (size_t i = 0; i < 97; ++i) {
+    msg_length +=
+        snprintf(mqtt_msg + msg_length, sizeof(mqtt_msg) - msg_length, "%s%d", (i == 0) ? "" : ", ", cell_voltages[i]);
+  }
+  snprintf(mqtt_msg + msg_length, sizeof(mqtt_msg) - msg_length, "]\n}\n");
+
+  // Publish and print error if not OK
+  if (mqtt_publish_retain("battery/spec_data") == false) {
+    Serial.println("Nissan MQTT msg could not be sent");
+  }
+}
+#endif

Software/src/devboard/mqtt/mqtt.cpp

@@ -0,0 +1,102 @@
+#include "mqtt.h"
+#include <Arduino.h>
+#include <WiFi.h>
+#include <freertos/FreeRTOS.h>
+#include "../../../USER_SETTINGS.h"
+#include "../../lib/knolleary-pubsubclient/PubSubClient.h"
+#include "../utils/timer.h"
+
+const char* mqtt_subscriptions[] = MQTT_SUBSCRIPTIONS;
+const size_t mqtt_nof_subscriptions = sizeof(mqtt_subscriptions) / sizeof(mqtt_subscriptions[0]);
+
+WiFiClient espClient;
+PubSubClient client(espClient);
+char mqtt_msg[MSG_BUFFER_SIZE];
+int value = 0;
+static unsigned long previousMillisUpdateVal;
+MyTimer publish_global_timer(5000);
+
+/** Publish global values and call callbacks for specific modules */
+static void publish_values(void) {
+
+  snprintf(mqtt_msg, sizeof(mqtt_msg),
+           "{\n"
+           "  \"SOC\": %.3f,\n"
+           "  \"StateOfHealth\": %.3f,\n"
+           "  \"temperature_min\": %.3f,\n"
+           "  \"temperature_max\": %.3f,\n"
+           "  \"cell_max_voltage\": %d,\n"
+           "  \"cell_min_voltage\": %d\n"
+           "}\n",
+           ((float)SOC) / 100.0, ((float)StateOfHealth) / 100.0, ((float)((int16_t)temperature_min)) / 10.0,
+           ((float)((int16_t)temperature_max)) / 10.0, cell_max_voltage, cell_min_voltage);
+  bool result = client.publish("battery/info", mqtt_msg, true);
+  Serial.println(mqtt_msg);  // Uncomment to print the payload on serial
+}
+
+/* This is called whenever a subscribed topic changes (hopefully) */
+static void callback(char* topic, byte* payload, unsigned int length) {
+  Serial.print("Message arrived [");
+  Serial.print(topic);
+  Serial.print("] ");
+  for (unsigned int i = 0; i < length; i++) {
+    Serial.print((char)payload[i]);
+  }
+  Serial.println();
+}
+
+/* If we lose the connection, get it back and re-sub */
+static void reconnect() {
+  // attempt one reconnection
+  Serial.print("Attempting MQTT connection... ");
+  // Create a random client ID
+  String clientId = "LilyGoClient-";
+  clientId += String(random(0xffff), HEX);
+  // Attempt to connect
+  if (client.connect(clientId.c_str(), mqtt_user, mqtt_password)) {
+    Serial.println("connected");
+
+    for (int i = 0; i < mqtt_nof_subscriptions; i++) {
+      client.subscribe(mqtt_subscriptions[i]);
+      Serial.print("Subscribed to: ");
+      Serial.println(mqtt_subscriptions[i]);
+    }
+  } else {
+    Serial.print("failed, rc=");
+    Serial.print(client.state());
+    Serial.println(" try again in 5 seconds");
+    // Wait 5 seconds before retrying
+  }
+}
+
+void init_mqtt(void) {
+  client.setServer(MQTT_SERVER, MQTT_PORT);
+  client.setCallback(callback);
+  Serial.println("MQTT initialized");
+
+  previousMillisUpdateVal = millis();
+  reconnect();
+}
+
+void mqtt_loop(void) {
+  if (client.connected()) {
+    client.loop();
+    if (publish_global_timer.elapsed() == true)  // Every 5s
+    {
+      publish_values();  // Update values heading towards inverter. Prepare for sending on CAN, or write directly to Modbus.
+    }
+  } else {
+    if (millis() - previousMillisUpdateVal >= 5000)  // Every 5s
+    {
+      previousMillisUpdateVal = millis();
+      reconnect();  // Update values heading towards inverter. Prepare for sending on CAN, or write directly to Modbus.
+    }
+  }
+}
+
+bool mqtt_publish_retain(const char* topic) {
+  if (client.connected() == true) {
+    return client.publish(topic, mqtt_msg, true);
+  }
+  return false;
+}

Software/src/devboard/mqtt/mqtt.h

@@ -0,0 +1,62 @@
+/**
+ * MQTT add-on for the battery emulator
+ * 
+ * Usage:
+ * 
+ * Subscription - Add topics to MQTT_SUBSCRIPTIONS in USER_SETTINGS.h and handle the messages in mqtt.cpp:callback()
+ * 
+ * Publishing - See example in mqtt.cpp:publish_values() for constructing the payload
+ * 
+ * Home assistant - See below for an example, and the official documentation is quite good (https://www.home-assistant.io/integrations/sensor.mqtt/)
+ * in configuration.yaml:
+ * mqtt: !include mqtt.yaml
+ * 
+ * in mqtt.yaml:
+ * sensor:
+ *   - name: "Cell max"
+ *       state_topic: "battery/info"
+ *       unit_of_measurement: "mV"
+ *       value_template: "{{ value_json.cell_max_voltage | int }}"
+ *   - name: "Cell min"
+ *       state_topic: "battery/info"
+ *       unit_of_measurement: "mV"
+ *       value_template: "{{ value_json.cell_min_voltage | int }}"
+ *   - name: "Temperature max"
+ *       state_topic: "battery/info"
+ *       unit_of_measurement: "C"
+ *       value_template: "{{ value_json.temperature_max | float }}"
+ *   - name: "Temperature min"
+ *       state_topic: "battery/info"
+ *       unit_of_measurement: "C"
+ *       value_template: "{{ value_json.temperature_min | float }}"
+ */
+
+#ifndef __MQTT_H__
+#define __MQTT_H__
+
+#include <Arduino.h>
+#include "../../../USER_SETTINGS.h"
+
+#define MSG_BUFFER_SIZE (1024)
+#define MQTT_SUBSCRIPTIONS \
+  { "my/topic/abc", "my/other/topic" }
+#define MQTT_SERVER "192.168.xxx.yyy"
+#define MQTT_PORT 1883
+
+extern uint16_t SOC;
+extern uint16_t StateOfHealth;
+extern uint16_t temperature_min;   //C+1,  Goes thru convert2unsignedint16 function (15.0C = 150, -15.0C =  65385)
+extern uint16_t temperature_max;   //C+1,  Goes thru convert2unsignedint16 function (15.0C = 150, -15.0C =  65385)
+extern uint16_t cell_max_voltage;  //mV,   0-4350
+extern uint16_t cell_min_voltage;  //mV,   0-4350
+
+extern const char* mqtt_user;
+extern const char* mqtt_password;
+
+extern char mqtt_msg[MSG_BUFFER_SIZE];
+
+void init_mqtt(void);
+void mqtt_loop(void);
+bool mqtt_publish_retain(const char* topic);
+
+#endif

Software/src/devboard/utils/timer.cpp

@@ -0,0 +1,12 @@
+#include "timer.h"
+
+MyTimer::MyTimer(unsigned long interval) : interval(interval), previousMillis(0) {}
+
+bool MyTimer::elapsed() {
+  unsigned long currentMillis = millis();
+  if (currentMillis - previousMillis >= interval) {
+    previousMillis = currentMillis;
+    return true;
+  }
+  return false;
+}

Software/src/devboard/utils/timer.h

@@ -0,0 +1,18 @@
+#ifndef __MYTIMER_H__
+#define __MYTIMER_H__
+
+#include <Arduino.h>
+
+class MyTimer {
+ public:
+  /** interval in ms */
+  MyTimer(unsigned long interval);
+  /** Returns true and resets the timer if it has elapsed */
+  bool elapsed();
+
+ private:
+  unsigned long interval;
+  unsigned long previousMillis;
+};
+
+#endif  // __MYTIMER_H__

Software/src/devboard/webserver/webserver.cpp

@@ -219,6 +219,11 @@ void init_webserver() {
 
   // Start server
   server.begin();
+
+#ifdef MQTT
+  // Init MQTT
+  init_mqtt();
+#endif
 }
 
 void init_WiFi_AP() {

Software/src/devboard/webserver/webserver.h

@@ -5,10 +5,16 @@
 #include <WiFi.h>
 #include "../../../USER_SETTINGS.h"  // Needed for WiFi ssid and password
 #include "../../lib/ayushsharma82-ElegantOTA/src/ElegantOTA.h"
+#ifdef MQTT
+#include "../../lib/knolleary-pubsubclient/PubSubClient.h"
+#endif
 #include "../../lib/me-no-dev-AsyncTCP/src/AsyncTCP.h"
 #include "../../lib/me-no-dev-ESPAsyncWebServer/src/ESPAsyncWebServer.h"
 #include "../../lib/miwagner-ESP32-Arduino-CAN/ESP32CAN.h"
 #include "../config.h"  // Needed for LED defines
+#ifdef MQTT
+#include "../mqtt/mqtt.h"
+#endif
 
 extern uint16_t SOC;                         //SOC%, 0-100.00 (0-10000)
 extern uint16_t StateOfHealth;               //SOH%, 0-100.00 (0-10000)