How does this work with COMMAND_CELL_INFO and COMMAND_DEVICE_INFO?

[peff74]

I have the problem that the ESP Home version does not run stably with 2 BMS.
That's why I'm trying an Android version, but I can't get any data for the life of me.
BLE connects and when I send the two arrays, the BMS beeps.
However, no data is received and the LED does not flicker quickly, as it does when transmitting

The Arduino sketches that are available always contain the same arrays

byte getdeviceInfo[20] = {0xaa, 0x55, 0x90, 0xeb, 0x97, 0x00, 0xdf, 0x52, 0x88, 0x67, 0x9d, 0x0a, 0x09, 0x6b, 0x9a, 0xf6, 0x70, 0x9a, 0x17, 0xfd}; 
byte getInfo[20]       = {0xaa, 0x55, 0x90, 0xeb, 0x96, 0x00, 0x79, 0x62, 0x96, 0xed, 0xe3, 0xd0, 0x82, 0xa1, 0x9b, 0x5b, 0x3c, 0x9c, 0x4b, 0x5d}; 

Is it possible that these do not work for all BMS?
I want to use this one.

Then I saw that you generate the arrays completely differently.

bool JkBmsBle::write_register(uint8_t address, uint32_t value, uint8_t length) {
  uint8_t frame[20];
  frame[0] = 0xAA;     // start sequence
  frame[1] = 0x55;     // start sequence
  frame[2] = 0x90;     // start sequence
  frame[3] = 0xEB;     // start sequence
  frame[4] = address;  // holding register
  frame[5] = length;   // size of the value in byte
  frame[6] = value >> 0;
  frame[7] = value >> 8;
  frame[8] = value >> 16;
  frame[9] = value >> 24;
  frame[10] = 0x00;
  frame[11] = 0x00;
  frame[12] = 0x00;
  frame[13] = 0x00;
  frame[14] = 0x00;
  frame[15] = 0x00;
  frame[16] = 0x00;
  frame[17] = 0x00;
  frame[18] = 0x00;
  frame[19] = crc(frame, sizeof(frame) - 1);

  ESP_LOGD(TAG, "Write register: %s", format_hex_pretty(frame, sizeof(frame)).c_str());
  auto status =
      esp_ble_gattc_write_char(this->parent_->get_gattc_if(), this->parent_->get_conn_id(), this->char_handle_,
                               sizeof(frame), frame, ESP_GATT_WRITE_TYPE_NO_RSP, ESP_GATT_AUTH_REQ_NONE);

  if (status) {
    ESP_LOGW(TAG, "[%s] esp_ble_gattc_write_char failed, status=%d", this->parent_->address_str().c_str(), status);
  }

  return (status == 0);
}

the first bytes are identical but then you have many zero values.
The BMS works with your version, can you perhaps explain what has changed?
Because I don't really like the idea of taking everything apart first with btsnoop or something, and on the other hand I don't understand your code 100% :-)

[syssi]

Byte 10 upto 18 are random bytes. The content of the first 5 bytes is important to request the cell info frame or the device info frame

https://github.com/syssi/esphome-jk-bms/blob/main/components/jk_bms_ble/jk_bms_ble.cpp#L20-L21
https://github.com/syssi/esphome-jk-bms/blob/main/components/jk_bms_ble/jk_bms_ble.cpp#L246

You have to make sure the last byte (pos. 19) is a valid checksum of the payload.

Did you subscribe to the BLE notification stream?

https://github.com/syssi/esphome-jk-bms/blob/main/components/jk_bms_ble/jk_bms_ble.cpp#L205-L206

[peff74]

Thank you for your quick feedback!
OK, that clarifies why the bytes 10-18 and 19 are different.

In the Arduino versions, a previously known variant is simply used and so the CRC fits and you calculate it.

In the Arduino, the reaction for a BLE notification is slightly different, but is implemented.

static void notifyCallback(BLERemoteCharacteristic* pBLERemoteCharacteristic, uint8_t* pData, size_t length, bool isNotify) {

  if (debug_flg_full_log) {
    Serial.print("Notify callback for characteristic ");
    Serial.print(pBLERemoteCharacteristic->getUUID().toString().c_str());
    Serial.print(" of data length ");
    Serial.println(length);
    Serial.print("data: ");
    for (int i = 0; i < length; i++)  {
      Serial.print(pData[i], HEX);
      Serial.print(", ");
    }
    Serial.println("");
  }
  if (pData[0] == 0x55 && pData[1] == 0xAA && pData[2] == 0xEB && pData[3] == 0x90 && pData[4] == 0x02) {
    Serial.println("Daten anerkannt !");
    received_start = true;
    received_start_frame = true;
    received_complete = false;
    frame = 0;
    for (int i = 0; i < length; i++)  {
      receivedBytes_main[frame] = pData[i];
      frame++;
    }
  }

  if (received_start && !received_start_frame && !received_complete) {
    //     Serial.println("Daten erweitert !");
    for (int i = 0; i < length; i++)  {
      receivedBytes_main[frame] = pData[i];
      frame++;
    }

    if (frame == 300) {
      Serial.println("New Data for Analyse Complete...");
      received_complete = true;
      received_start = false;
      new_data = true;
      BLE_Scan_counter = 0;
    }
    if ((frame > 300)) {

      Serial.println("Fehlerhafte Daten !!");
      frame = 0;
      received_start = false;
      new_data = false;
    }

  }

But somehow it is not triggered.
It is also strange that the led does not flash as quickly as when data is being sent.

The LED has 3 types,
Very slow flashing --> not connected
slow flashing --> connected
fast flashing --> communication

[syssi]

Could you show your complete implementation and provide the debug output?

[peff74]

of cousre, it is a smal one from the akkudoctor-forum.
BLE_client_523.zip

debug output

Connected to server
Found our service
Found our characteristic
Sending device Info
We are now connected to the BLE Server.
gesendet!

I have tried to compile it with different core versions.
From 1.06 to 3.10.
Always the same result, except that with the newer cores
String value = pRemoteCharacteristic->readValue();
instead of
std::string value = pRemoteCharacteristic->readValue();
must be used.
I even try to use the old 1.8 IDE ^^

[syssi]

Did you update line 16:

const char* Geraetename = "JK_BD6A17S6P";  //JK-B2A24S20P JK-B2A24S15P

to the BLE name of your device? The attached code did work out of the box on my side:

data: 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, D0, DD, 6, 0, 8, 0, 0, 0, 0, 7C, F8, FF, FF, 1F, D, 0, 0, 0, 0, 0, 0, DC, 
Notify callback for characteristic 0000ffe1-0000-1000-8000-00805f9b34fb of data length 20
data: AA, 55, 90, EB, C8, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 44, 
Notify callback for characteristic 0000ffe1-0000-1000-8000-00805f9b34fb of data length 150
data: 55, AA, EB, 90, 2, 0, A2, D, A2, D, A2, D, E4, D, DE, D, E4, D, E5, D, 5, E, 5, E, E, E, 4, E, C0, C, A4, D, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, FF, 1F, 0, 0, C4, D, 4E, 1, 9, B, A1, 0, A3, 0, A4, 0, A3, 0, A2, 0, A4, 0, A3, 0, A6, 0, A4, 0, A3, 0, A3, 0, BF, 0, BF, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, C0, 0, 0, 0, 0, 0, 
Daten anerkannt !
Notify callback for characteristic 0000ffe1-0000-1000-8000-00805f9b34fb of data length 150
data: EF, B2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, BF, 0, C2, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 40, 9C, 0, 0, 0, 0, 0, 0, EA, 3, 0, 0, 64, 0, 0, 0, CB, 78, 7, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, FF, 0, 1, 0, 0, 0, 50, 3, 0, 0, 0, 0, 27, 65, 3F, 40, 0, 0, 0, 0, E4, 11, 47, 15, 0, 1, 0, 1, 0, 5, 0, 0, F2, 2, 0, 0, 0, 0, 0, 0, C0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, FE, FF, 7F, DC, F, 1, 0, 0, 0, 0, 0, 0, 22, 
New Data for Analyse Complete...
Cell Voltages = 3.490V, 3.490V, 3.490V, 3.556V, 3.550V, 3.556V, 3.557V, 3.589V, 3.589V, 3.598V, 3.588V, 3.264V, 3.492V, 0.000V, 0.000V, 0.000V
Average Cell Voltage = 3.524V, 
Delta Cell Voltage = 0.334V, 
Battery Voltage = 45.807V, 
Battery Power = 0.000W, 
Charge Current = 0.000A, 
Battery T1 = 19.100°C, 
Battery T2 = 19.400°C, 
MOS Temp = 19.200°C, 
Balance_Curr = 0.000A, 
Percent Remain = 0%, 
Capacity Remain = 0.000, 
Nominal Capacity = 40.000, 
Cycle Count = 0, 
Capacity Cycle = 0.000, 
Tage: 5 Stunden: 16 Minuten: 1 Sekunden: 15
Charge on? = on, 
Discharge on? = on, 

[peff74]

Yes, I pasted my BMS name in Line 16:

And if the name doesn't fit... then it doesn't connect either

That's crazy. Which IDE and core did you use?

Could you post the debug since the start of the ESP here.

[peff74]

I have now compiled your version for the BMS mentioned above, which makes the connection work.
Funny.
Something must be working differently.
Right at the beginning.
With the Arduino version, the BLE LED of the BMS flashes much more slowly.
Even at the first beep, i.e. after transferring the array with the 97.

[peff74]

I have now converted the whole thing to NimBLE Arduino.
By adapting the NinBLE example a little and implementing the data analysis of the script from the Akkudoktor forum, it now works.
I already thought I was crazy.

The question that remains unanswered is why the BD4A20S4P version of the JK-BMS does not work with the standard BLE library from Arduino, but many other JK-BMS versions apparently do.

Maybe it is due to specific IDE or core versions?
@syssi
Which versions did you compile with? Because it worked for you