[BK7231N] Generic Smart Wi-Fi IR Remote Control from Temu

Photos:


Bought the device from Temu.

The product image shows a model number of IRC02. The manual in box was for SRW-001, but the schematic looks like a different product. Although the chassis seems to be the same as Aubess WiFi Smart IR Controller, the internals are quite different.

There are four tabs holding the two pieces of outer shell together. Once opened, the board can be taken out directly. The chip used is CB3S which is a BK7231N. The TXD, RXD, GND, and 3V3 pins are easily accessible.

For the flashing, I repurposed a ESP-12E development board by grounding the EN pin and then connecting TXD, RXD, GND, and 3V3 directly to the testpins on the IR remote board (Note: TXD to TXD and RXD to RXD. Not the other way around). The onboard USB to TTL chip was a CP2102 and requires drivers from Silicon Labs to work. The firmware used is OpenBK7231N_QIO_1.15.384.bin



The Pin layout is as follows:

Pin	Setting
6	Btn
7	LEN or WifiLED
24	IRRecv
26	IRSend

Note: After saving pin settings, a reboot is required before the IR will work.

IMHO, the most difficult part of getting this device to work was figuring out the pin layout. Even though the number of pins is limited, setting IRRecv/Send does require reboot which lengthens the process. I was able to figure out the button and LED pins, but the IR pins were difficult to brute-force. In the end, I tried the profile building script from the tuya-wirecutter repo on the backed up original firmware dump, and was able to get the user_param_key.json file which provided the hint I needed.



Hope this helps. Happy tinkering!