I see no readings, how to eliminate hardware issues or find out what is wrong?

[Svanberg1]

Hi everyone,

Super excited about this project and my JK BMS which is working like a charm, but it would be awsome if I could control it remotely since my array is way off grid out at the family cabin and I won't be there always when its used.

After a long wait for a JST 1.25mm pitch it finally arrived today, I am struggling to get it to work. My ESP32 is up and running after some overstack issues that I could solve (removing unnecessary sensors) -- but I don't get any readings. The log just shows an endless line of:
[01:13:34][D][uart_debug:114]: >>> 4E:57:00:13:00:00:00:00:06:03:00:00:00:00:00:00:68:00:00:01:29

Does anyone have any tips for how to find out what is wrong? One alternative is of course a hardware issue. The JST is darn small and the connection from the pins of the ESP 32 to the cable could be default (although it would surprise me). Is there any way to check this? Anyone have any other ideas?

[syssi]

Which JK-BMS model and version do you own? Old BMS versions are using another protocol. Could you provide a photo of your wiring? Do you own a multimeter to measure continuity?

[syssi]

We should name the sensors / entities properly. Could you try something like this:

substitutions:
  name: jk-bms
  name_bms0: "${name} bms0"
  name_bms1: "${name} bms1"
  device_description: "Monitor and control a JK-BMS via UART-TTL"
  external_components_source: github://syssi/esphome-jk-bms@main
  tx_pin: GPIO1
  rx_pin: GPIO3
  tx_pin2: GPIO4
  rx_pin2: GPIO5

esphome:
  name: ${name}
  comment: ${device_description}
  project:
    name: "syssi.esphome-jk-bms"
    version: 1.2.0

esp8266:
  board: d1_mini

external_components:
  - source: ${external_components_source}
    refresh: 0s

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

ota:
logger:
  baud_rate: 0

mqtt:
  broker: !secret mqtt_host
  username: !secret mqtt_username
  password: !secret mqtt_password
  id: mqtt_client

uart:
  - id: uart0
    baud_rate: 115200
    rx_buffer_size: 384
    tx_pin: ${tx_pin}
    rx_pin: ${rx_pin}
  - id: uart1
    baud_rate: 115200
    rx_buffer_size: 384
    tx_pin: ${tx_pin2}
    rx_pin: ${rx_pin2}

jk_modbus:
  - id: modbus0
    uart_id: uart0
  - id: modbus1
    uart_id: uart1

jk_bms:
  - id: bms0
    jk_modbus_id: modbus0
  - id: bms1
    jk_modbus_id: modbus1

binary_sensor:
  - platform: jk_bms
    jk_bms_id: bms0
    balancing:
      name: "${name_bms0} balancing"
    charging:
      name: "${name_bms0} charging"
    # ...

  - platform: jk_bms
    jk_bms_id: bms1
    balancing:
      name: "${name_bms1} balancing"
    charging:
      name: "${name_bms1} charging"
    # ...

sensor:
  - platform: jk_bms
    jk_bms_id: bms0
    total_voltage:
      name: "${name_bms0} total voltage"
    current:
      name: "${name_bms0} current"
    power:
      name: "${name_bms0} power"
    # ...

  - platform: jk_bms
    jk_bms_id: bms1
    total_voltage:
      name: "${name_bms1} total voltage"
    current:
      name: "${name_bms1} current"
    power:
      name: "${name_bms1} power"
    # ...

[vrabi-cv]

this one is perfect. Now I can see both of them, each has got its own name.
Thanks a lot!

[filippomasoni]

Hello, I'm having the same issue and I have the same version of the BMS as @vrabi-cv and using the same 8266 a wemos d1 mini and wiring on the GPS port. I checked VBAT with the multimeter to be on the left, like the image above posted by @syssi, so I think I have everything wired correctly, as you can see in the photos below. On the display port I have the momentary switch with a diode to turn on and off the bms, which works.

What an I doing wrong?

YAML code:

substitutions:
  name: jk-bms-d1
  device_description: "Monitor a JK-BMS using the GPS port (UART-TTL)"
  external_components_source: github://syssi/esphome-jk-bms@main
  tx_pin: GPIO1
  rx_pin: GPIO3

esphome:
  name: ${name}
  friendly_name: ${name}
  comment: ${device_description}
  min_version: 2024.6.0
  project:
    name: "syssi.esphome-jk-bms"
    version: 2.1.0

esp8266:
  board: d1_mini

external_components:
  - source: ${external_components_source}
    refresh: 0s

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

ota:
  - platform: esphome
    password: "***"

# Enable logging
logger:
  baud_rate: 0
  level: DEBUG

# Enable Home Assistant API
api:
  encryption:
    key: "***"


uart:
  - id: uart_0
    baud_rate: 115200
    rx_buffer_size: 384
    tx_pin: ${tx_pin}
    rx_pin: ${rx_pin}
    debug:
      direction: BOTH

jk_modbus:
  - id: modbus0
    uart_id: uart_0
    rx_timeout: 50ms

jk_bms:
  - id: bms0
    jk_modbus_id: modbus0
    update_interval: 5s

binary_sensor:
  - platform: jk_bms
    balancing:
      name: "${name} balancing"
    balancing_switch:
      name: "${name} balancing switch"
    charging:
      name: "${name} charging"
    discharging:
      name: "${name} discharging"
    dedicated_charger_switch:
      name: "${name} dedicated charger switch"
    online_status:
      name: "${name} online status"

And here is the log:

INFO ESPHome 2024.11.3
INFO Reading configuration /config/esphome/jk-bms-d1.yaml...
INFO Updating https://github.com/syssi/esphome-jk-bms.git@main
INFO Starting log output from 192.168.178.84 using esphome API
INFO Successfully connected to jk-bms-d1 @ 192.168.178.84 in 0.003s
INFO Successful handshake with jk-bms-d1 @ 192.168.178.84 in 2.706s
[11:43:37][I][app:100]: ESPHome version 2024.11.3 compiled on Dec 17 2024, 11:25:06
[11:43:37][I][app:102]: Project syssi.esphome-jk-bms version 2.1.0
[11:43:37][C][wifi:600]: WiFi:
[11:43:37][C][wifi:428]:   Local MAC: C4:5B:BE:DE:3B:78
[11:43:37][C][wifi:433]:   SSID: [redacted]
[11:43:37][C][wifi:436]:   IP Address: 192.168.178.84
[11:43:37][C][wifi:439]:   BSSID: [redacted]
[11:43:37][C][wifi:441]:   Hostname: 'jk-bms-d1'
[11:43:37][C][wifi:443]:   Signal strength: -56 dB ▂▄▆█
[11:43:37][C][wifi:447]:   Channel: 6
[11:43:37][C][wifi:448]:   Subnet: 255.255.255.0
[11:43:37][C][wifi:449]:   Gateway: 192.168.178.1
[11:43:37][C][wifi:450]:   DNS1: 192.168.178.1
[11:43:37][C][wifi:451]:   DNS2: 0.0.0.0
[11:43:37][C][logger:185]: Logger:
[11:43:37][C][logger:186]:   Level: DEBUG
[11:43:37][C][logger:188]:   Log Baud Rate: 0
[11:43:37][C][logger:189]:   Hardware UART: UART0
[11:43:37][C][uart.arduino_esp8266:118]: UART Bus:
[11:43:37][C][uart.arduino_esp8266:119]:   TX Pin: GPIO1
[11:43:37][C][uart.arduino_esp8266:120]:   RX Pin: GPIO3
[11:43:37][C][uart.arduino_esp8266:122]:   RX Buffer Size: 384
[11:43:37][C][uart.arduino_esp8266:124]:   Baud Rate: 115200 baud
[11:43:37][C][uart.arduino_esp8266:125]:   Data Bits: 8
[11:43:37][C][uart.arduino_esp8266:126]:   Parity: NONE
[11:43:37][C][uart.arduino_esp8266:127]:   Stop bits: 1
[11:43:37][C][uart.arduino_esp8266:129]:   Using hardware serial interface.
[11:43:37][C][jk_modbus:113]: JkModbus:
[11:43:37][C][jk_modbus:114]:   RX timeout: 50 ms
[11:43:37][C][jk_bms:545]: JkBms:
[11:43:37][C][jk_bms:546]:   Address: 0x4E
[11:43:37][C][jk_bms:634]: Balancing 'jk-bms-d1 balancing'
[11:43:37][C][jk_bms:635]: Balancing Switch 'jk-bms-d1 balancing switch'
[11:43:37][C][jk_bms:636]: Charging 'jk-bms-d1 charging'
[11:43:37][C][jk_bms:638]: Discharging 'jk-bms-d1 discharging'
[11:43:37][C][jk_bms:640]: Dedicated Charger Switch 'jk-bms-d1 dedicated charger switch'
[11:43:37][C][mdns:116]: mDNS:
[11:43:37][C][mdns:117]:   Hostname: jk-bms-d1
[11:43:37][C][esphome.ota:073]: Over-The-Air updates:
[11:43:37][C][esphome.ota:074]:   Address: jk-bms-d1.local:8266
[11:43:37][C][esphome.ota:075]:   Version: 2
[11:43:37][C][esphome.ota:078]:   Password configured
[11:43:37][C][safe_mode:018]: Safe Mode:
[11:43:37][C][safe_mode:019]:   Boot considered successful after 60 seconds
[11:43:37][C][safe_mode:021]:   Invoke after 10 boot attempts
[11:43:37][C][safe_mode:022]:   Remain in safe mode for 300 seconds
[11:43:37][C][api:140]: API Server:
[11:43:37][C][api:141]:   Address: jk-bms-d1.local:6053
[11:43:37][C][api:143]:   Using noise encryption: YES
[11:43:42][D][uart_debug:114]: >>> 4E:57:00:13:00:00:00:00:06:02:00:00:00:00:00:00:68:00:00:01:28
[11:43:46][D][uart_debug:114]: >>> 4E:57:00:13:00:00:00:00:06:02:00:00:00:00:00:00:68:00:00:01:28
[11:43:51][D][uart_debug:114]: >>> 4E:57:00:13:00:00:00:00:06:02:00:00:00:00:00:00:68:00:00:01:28
[11:43:56][D][uart_debug:114]: >>> 4E:57:00:13:00:00:00:00:06:02:00:00:00:00:00:00:68:00:00:01:28
[11:44:02][D][uart_debug:114]: >>> 4E:57:00:13:00:00:00:00:06:02:00:00:00:00:00:00:68:00:00:01:28
[11:44:07][D][uart_debug:114]: >>> 4E:57:00:13:00:00:00:00:06:02:00:00:00:00:00:00:68:00:00:01:28

[syssi]

GPIO1/GPIO3 are attached to a USB-to-TTL converter. The JK-BMS is pretty picky and doesn't like to share a GPIO with other components. Please try to use a floating GPIO f.e. GPIO4/GPIO5. The ESP8266 is pretty limited because the hardware UART is wired to specific GPIOs. I recommend to use an ESP32 because of the GPIO matrix. The hardware UART can be configured to any GPIO and SoftwareSerial isn't required.

[filippomasoni]

Thank you so much for the quick reply. I switched to GPIO4/GPIO5 and that worked! I knew about the hardware uart issue but since the example yaml specified GPIO1/GPIO3 for the d1 mini I though that was correct. I also saw that in the log I had hardware UART, not it says software UART, so basically every other regular pin can be used as software but as the hardware are already used it can be problematic.

I actually tried an ESP32 C3 mini by lolin before the 8266 because of the recommendation, but that would not even connect to the wifi once I started to use the hardware UART on GPIO20/21. Does that mean I also need to use different pins on the ESP32 C3? This is the pinout