Connect to BMS using Bluetooth UART

[23900]

I'm trying to connect to BMS directly with BLE UART.

                UART-TTL
┌──────────┐                ┌─────────────┐                ┌──────────┐
│          │<----- RX ------│tx1       rx2│<----- RX ------│          │
│  JK-BMS  │------ TX ----->│rx1 ESP32 tx2│------ TX ----->│ JK-BMS   │
│          │<----BLE_EN ----│             │<----BLE_STA----│ Bluetooth│
│          │------ 3.3v---->│             │------ 3.3v---->│ module   │
│          │<----- GND ---->│             │<----- GND----->│          │
│          │                │             │                │          │
└──────────┘                └─────────────┘                └──────────┘

Use ESP32 to bridge two uarts.

https://github.com/ssieb/esphome_components/tree/master/components/uart_mitm

  ble_sta_pin: GPIO15
  ble_en_pin: GPIO2

  rx_pin_uart_0: GPIO3
  tx_pin_uart_0: GPIO1
  rx_pin_uart_1: GPIO4 #mcu tx
  tx_pin_uart_1: GPIO15 #mcu rx
  rx_pin_uart_2: GPIO2 #ble tx > rx
  tx_pin_uart_2: GPIO17 #ble rx < tx


uart:
  - id: uart_1
    baud_rate: 115200
    #rx_buffer_size: 384
    tx_pin: ${tx_pin_uart_1}
    rx_pin: ${rx_pin_uart_1}

  - id: uart_2
    baud_rate: 115200
    #stop_bits: 1
    #rx_buffer_size: 384
    tx_pin: ${tx_pin_uart_2}
    rx_pin: ${rx_pin_uart_2}


uart_mitm:
  uart1: uart_1
  uart2: uart_2

binary_sensor:
  - platform: gpio
    name: "Bluetooth STA"
    pin: ${ble_sta_pin}
    id: ble_sta
  #Manually enable BLE_EN,
   # on_press:
   #   then:
   #     - switch.turn_on: ble_en
    on_release:
      then:
        - switch.turn_off: ble_en

switch:
  - platform: gpio
    name: "Bluetooth enabled"
    pin: ${ble_en_pin}
    id: ble_en

Hi @syssi , do you happen to have a code branch that incorporates UART and BLE protocols?
Apologies for my English proficiency.

[23900]

I attempted to establish a BLE UART connection without the need for AT commands after the device was powered on.

[23900]

After reviewing the logs again, following the BLE connection, there's a "BLE connected" indication with a high pin. The BLE tx sends "CONNECT OK" (hex: 434f4e4e454354204f4b0d0a), and the MCU tx sends the section for password settings. In fact, it matches the data in your JBK-ble connection.

[syssi]

If you start the BMS without powering the BLE module the BMS won't boot properly?

[23900]

If BLE is not powered, starting the BMS produces three "beeps," followed by ten more "beeps." Subsequently, connecting BLE power enables a regular connection. However, in my earlier tests without connecting individual battery cells, the BMS sent an error signal. Hence, I should conduct a thorough test, encompassing charging, discharging, and balancing.

[23900]

Hi @syssi , after starting the BMS without connecting the Bluetooth module, I tested all functions, and everything is working fine. The BMS startup time is 16 seconds. When including AT command responses, the startup time is 5 seconds. AT commands are only used to configure the Bluetooth module.

AT commands excluding BLE.csv
AT commands including BLE.csv

[23900]

Available AT commands, I don’t know if they will affect performance.
JK-BMS-AT.yaml.txt

[syssi]

do you happen to have a code branch that incorporates UART and BLE protocols?

Not yet, unfortunately.

[23900]

To establish a safe connection with the battery pack, I am re-securing the ESP32 module.