Sebastian Muszynski

Summary: Please be careful!! If you send random data to the BMS it's possible to destroy the device. The bootloader of the ESP outputs some debug messages on bootup (`TXD`)....

@amagr0 Yes it is. See https://randomnerdtutorials.com/esp32-pinout-reference-gpios/ GPIO16 and GPIO17 aren't in use per default.

Does the TX led of the rs485 module blink periodically? Please make sure the TX led is blinking and not the RX led. Did you try to swap the RS485...

Could you try to swap the GPIOs at the yaml once. Does the RX led blink this time? I want to make sure the GPIOs are connected properly. You have...

> Can i just change the code in esphome? Pin4 14 Yes. This is the idea! So we can be sure the GPIOs are properly connected (without re-wiring).

This is super strange. I talked to some aliexpress seller of the BMS. He told me something like: Every BMS with firmware version `6 (f.e. 7.x and 8.x) should use...

How many cables did you connect to the BMS?

A side note: If your BMS doesn't provide VBAT the original RS485 adapter won't be powered properly and cannot work.

Yes. It's the same protocol. The is the command to query the current status: https://github.com/Louisvdw/dbus-serialbattery/blob/master/etc/dbus-serialbattery/jkbms.py#L19 This component does the same here: https://github.com/syssi/esphome-jk-bms/blob/main/components/jk_modbus/jk_modbus.cpp#L126-L147

Could you try to use the python implementation by connecting the BMS to a TTL-to-USB adapter?