Picked my KW902 apart today to see what’s inside. It features probably a SN65HVDA1050A CAN tranciever (ISO 11898-2 high speed up tp 1 Mbps) a BK3231S SoC for Bluetooth 3.0 and 4.0 programmable via JTAG/FLASH both controlled by a PIC18F25K80 (cheapest of the family, also up to 1Mbps bit rate, comforms to CAN 2.0B) programmable via ICSP.
![](http://duke.famkos.net/wp-content/uploads/2019/04/IMG_20190317_192845-1024x768.jpg)
The pins for ICSP may be exposed on the cable for the LED and RST button but since I don’t have the equipment to read out the firmware I didn’t look too closely and called it a day – for now. This cheap IC costs ~2 EUR btw and is well documented.