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syssi / esphome-jk-bms

ESPHome component to monitor and control a Jikong Battery Management System (JK-BMS) via UART-TTL or BLE
Apache License 2.0
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UART (non BLE) version appears to not be able to control switches #130

Closed derekyle closed 2 years ago

derekyle commented 2 years ago

I don't see any mention in the readme, and in fact, the readme seems to focus solely on the uart method of connection, but I can't seem to get the switches to show up in Home Assistant. I am using the api method rather than mqtt.

Is this a limitation of the uart protocol? Do I need to use an esp32 and use bluetooth in order to control the charge/dischange/balance switches from within home assistant?

syssi commented 2 years ago

This is a limitation of the UART protocol if we trust the seller & manufacturer. It's read-only. May be new software versions will allow write operations some day. You have to use an ESP32 + BLE if you want to control the BMS.

This is my idea for a future release of this component:

  1. Turn off the BLE module by pulling to RST pin to GND: https://github.com/syssi/esphome-jk-bms/issues/107
  2. Add wires to RX, TX, GND, P11 and P12 of the bluetooth module: https://github.com/syssi/esphome-jk-bms/issues/108
  3. Rewrite the JK02/04 protocol implementation to skip BLE as transport layer and use UART-TTL to talk directly to the BMS (using the JK02/04 protocol)
derekyle commented 2 years ago

Interesting. Do most jkbms units have a separate Bluetooth module? Or is this something that needs to be accessed on the internal board?

syssi commented 2 years ago

You have to open the case to access the pins. It's always internal:

https://raw.githubusercontent.com/syssi/esphome-jk-bms/main/images/jk-bd6a17s6p/004.jpg https://raw.githubusercontent.com/syssi/esphome-jk-bms/main/images/jk-bd6a17s6p/005-labeled.jpg

derekyle commented 2 years ago

I see. Thank you very much for your work on this project. It has been very helpful to be able to easily connect my BMS into my Home Assistant.

syssi commented 2 years ago

Thanks for your feedback! If you have no further questions feel free to close the issue. :-)

paulsteigel commented 8 months ago

Hi @syssi and all, I have recently purchased a JKBD6A20S10P and I built an esphome interface using your esp32-example.yaml with esp32lolin. However, the JKBMS does not response to query command via UAR TTL. This happened with my friends' version too (11.28 and 11.36, mine is 11.42). I think JK has changed the protocol. Can you advice on this?

The response code to the "4E:57:00:13:00:00:00:00:06:02:00:00:00:00:00:00:68:00:00:01:28" command is nothing and time out happened Please help with thanks. Best!