Could it work with new JK BMS's communication board's RS232 port?

[txubelaxu]

This is the new JK BMS: https://www.jkbms.com/product/jk-pb2a16s15p-jk-pb2a16s-15p/

It has a comms board with 5 ports:

• 1 RS485 ((RJ45) to be connected to Inverter
• 1 CAN (RJ45) to be connected to Inverter
• 1 RS232 (RJ11)
• 2 RS485 (RJ45) for paralling other (same) BMS

I have given a try to RS232 port but ESP uses modbus protocol.

Is any way to use serial protocol instead?

More info about HW:

[txubelaxu]

I have tested with no success. ESP32 (Serial2) connected directly to RS232 RJ11 connector. ESP32 RX pin in a pull-up input config. I send: byte bytesToSend[] = {0x4E, 0x57, 0x00, 0x13, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x68, 0x00, 0x00, 0x01, 0x29}; and... there is no response at all. I send: byte bytesToSend[] = {0x4E, 0x57, 0x00, 0x13, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x68, 0x00, 0x00, 0x01, 0x29, 0x13, 0x10}; and... no response at all.

I think it is because JK-BMS UART protocol is fixed to a kind of "GPS INPUT" and it cannot be changed from app:

If you try to change the setting, BMS responses that the new setting can not be saved.

[syssi]

@txubelaxu How many items / protocols are available at the drop-down?

[txubelaxu]

Hi syssi,

There are 3 lines in the settings menu item (status/settings/control) regarding to protocols: UART1 and CAN have "OK" button. UART2 has not. Anyway, "OK" button of UART1 does not work with all values, so any selection cannot be saved at this firmware/app version.

UART1 Protocol No.: has the next list inside: Some of the items are disabled in the list. The other ones are enabled, so you can select from the list but when applying the change using "OK" button a "Sending failure" message can appears. If you reload the screen you can see that the old setting (000 - 4G...) is the active value. So:

• 000 - 4G-GPS Remote module.... is selectable & activable (and default)
• 001 - JK BMS 485 Modbus v1.0... is selectable BUT NOT activable
• 002 - NIU U SERIES... is selectable & activable
• 003 - China tower shared battery cabinet... is selectable & activable
• 004 - PACE_RS485_Modbus_v1.3... is NOT selectable because is disabled
• 005 - PYLON_Low_voltage_Protocol_RS4... is NOT selectable because is disabled
• 006 - Growatt_BMS_RS485_Protocol... is selectable & activable
• 007 - Voltronic_inverter_and_BMS_485... is selectable & activable
• 008 - China tower shared battery cabinet... is selectable & activable
• 009 - WOW_RS485_Modbus_V1.3... is selectable & activable
• 010 - Protocol 10... is NOT selectable because is disabled

UART2 Protocol No.: 1 is fixed and has not a list.

CAN Protocol No. has the next list (I have not tested what values are selectable at this moment):

[txubelaxu]

See --> https://github.com/txubelaxu/esphome-jk-bms/blob/main/components/jk_rs485_bms/README.md

[txubelaxu]

See --> https://github.com/txubelaxu/esphome-jk-bms/blob/main/components/jk_rs485_bms/README.md

[kptkip]

The given link describes RS485 not RS232 definition

[gianfrdp]

I also am interested in RS232. I tried to connect PC App BMS Monitor w/o success. Could 00 protocol be same as old JK TTL one?