Add cellvoltage reading for BMW i3

Software/src/battery/BMW-I3-BATTERY.cpp

@@ -27,7 +27,7 @@ unsigned long turnOnTime;                    // Variables to store timestamps
 enum State { POWERON, STATE_ON, STATE_OFF };
 static State WUPState = POWERON;
 
-enum CmdState { SOH, CELL_VOLTAGE, SOC, CELL_VOLTAGE_AVG };
+enum CmdState { SOH, CELL_VOLTAGE_MINMAX, SOC, CELL_VOLTAGE_AVG, CELL_VOLTAGE_CELLNO };
 static CmdState cmdState = SOH;
 
 const unsigned char crc8_table[256] =
@@ -302,6 +302,13 @@ CAN_frame_t BMW_6F1_CELL_VOLTAGE_AVG = {.FIR = {.B =
                                                     }},
                                         .MsgID = 0x6F1,
                                         .data = {0x07, 0x03, 0x22, 0xDF, 0xA0}};
+CAN_frame_t BMW_6F1_CELL_VOLTAGE_CELLNO = {.FIR = {.B =
+                                                       {
+                                                           .DLC = 7,
+                                                           .FF = CAN_frame_std,
+                                                       }},
+                                           .MsgID = 0x6F1,
+                                           .data = {0x07, 0x05, 0x31, 0x01, 0xAD, 0x6E, 0x01}};
 
 CAN_frame_t BMW_6F1_CONTINUE = {.FIR = {.B =
                                             {
@@ -310,6 +317,13 @@ CAN_frame_t BMW_6F1_CONTINUE = {.FIR = {.B =
                                             }},
                                 .MsgID = 0x6F1,
                                 .data = {0x07, 0x30, 0x00, 0x02}};
+CAN_frame_t BMW_6F1_CELL_CONTINUE = {.FIR = {.B =
+                                                 {
+                                                     .DLC = 6,
+                                                     .FF = CAN_frame_std,
+                                                 }},
+                                     .MsgID = 0x6F1,
+                                     .data = {0x07, 0x04, 0x31, 0x03, 0xAD, 0x6E}};
 //The above CAN messages need to be sent towards the battery to keep it alive
 
 static uint8_t startup_counter_contactor = 0;
@@ -397,6 +411,7 @@ static uint8_t battery_soh = 99;
 
 static uint8_t message_data[50];
 static uint8_t next_data = 0;
+static uint8_t current_cell_polled = 1;
 
 static uint8_t calculateCRC(CAN_frame_t rx_frame, uint8_t length, uint8_t initial_value) {
   uint8_t crc = initial_value;
@@ -441,11 +456,6 @@ void update_values_battery() {  //This function maps all the values fetched via
 
   datalayer.battery.status.temperature_max_dC = battery_temperature_max * 10;  // Add a decimal
 
-  if (datalayer.battery.status.cell_voltages_mV[0] > 0 && datalayer.battery.status.cell_voltages_mV[2] > 0) {
-    datalayer.battery.status.cell_min_voltage_mV = datalayer.battery.status.cell_voltages_mV[0];
-    datalayer.battery.status.cell_max_voltage_mV = datalayer.battery.status.cell_voltages_mV[2];
-  }
-
   if (battery_info_available) {
     // Start checking safeties. First up, cellvoltages!
     if (detectedBattery == BATTERY_60AH) {
@@ -631,6 +641,16 @@ void receive_can_battery(CAN_frame_t rx_frame) {
       battery_ID2 = rx_frame.data.u8[0];
       break;
     case 0x607:  //BMS - responses to message requests on 0x615
+      if ((cmdState == CELL_VOLTAGE_CELLNO) && (rx_frame.data.u8[0] == 0xF4)) {
+        if (rx_frame.FIR.B.DLC == 6) {
+          ESP32Can.CANWriteFrame(&BMW_6F1_CELL_CONTINUE);  // tell battery to send the cellvoltage
+        }
+        if (rx_frame.FIR.B.DLC == 8) {  // We have the full value, map it
+          datalayer.battery.status.cell_voltages_mV[current_cell_polled - 1] =
+              (rx_frame.data.u8[6] << 8 | rx_frame.data.u8[7]);
+        }
+      }
+
       if (rx_frame.FIR.B.DLC > 6 && next_data == 0 && rx_frame.data.u8[0] == 0xf1) {
         uint8_t count = 6;
         while (count < rx_frame.FIR.B.DLC && next_data < 49) {
@@ -646,15 +666,15 @@ void receive_can_battery(CAN_frame_t rx_frame) {
         }
 
         switch (cmdState) {
-          case CELL_VOLTAGE:
+          case CELL_VOLTAGE_MINMAX:
             if (next_data >= 4) {
-              datalayer.battery.status.cell_voltages_mV[0] = (message_data[0] << 8 | message_data[1]);
+              datalayer.battery.status.cell_min_voltage_mV = (message_data[0] << 8 | message_data[1]);
-              datalayer.battery.status.cell_voltages_mV[2] = (message_data[2] << 8 | message_data[3]);
+              datalayer.battery.status.cell_max_voltage_mV = (message_data[2] << 8 | message_data[3]);
             }
             break;
           case CELL_VOLTAGE_AVG:
-            if (next_data >= 30) {
+            if (next_data >= 30) {  //AVG not used
-              datalayer.battery.status.cell_voltages_mV[1] = (message_data[10] << 8 | message_data[11]) / 10;
+              //datalayer.battery.status.cell_voltages_mV[1] = (message_data[10] << 8 | message_data[11]) / 10;
               battery_capacity_cah = (message_data[4] << 8 | message_data[5]);
             }
             break;
@@ -800,9 +820,9 @@ void send_can_battery() {
       switch (cmdState) {
         case SOC:
           ESP32Can.CANWriteFrame(&BMW_6F1_CELL);
-          cmdState = CELL_VOLTAGE;
+          cmdState = CELL_VOLTAGE_MINMAX;
           break;
-        case CELL_VOLTAGE:
+        case CELL_VOLTAGE_MINMAX:
           ESP32Can.CANWriteFrame(&BMW_6F1_SOH);
           cmdState = SOH;
           break;
@@ -811,6 +831,15 @@ void send_can_battery() {
           cmdState = CELL_VOLTAGE_AVG;
           break;
         case CELL_VOLTAGE_AVG:
+          ESP32Can.CANWriteFrame(&BMW_6F1_CELL_VOLTAGE_CELLNO);
+          cmdState = CELL_VOLTAGE_CELLNO;
+          current_cell_polled++;
+          if (current_cell_polled > 96) {
+            current_cell_polled = 1;
+          }
+          BMW_6F1_CELL_VOLTAGE_CELLNO.data.u8[6] = current_cell_polled;
+          break;
+        case CELL_VOLTAGE_CELLNO:
           ESP32Can.CANWriteFrame(&BMW_6F1_SOC);
           cmdState = SOC;
           break;