I have a Bluetooth ELM327 adapter that I am using with my car's OBD2 port. I have an Arduino UNO compatible Magpie (Little Bird Electronics) which I would like to use to interface with this adapter.
My current idea is to solder two wires onto the RX/TX lines (If they exist/can be found) or to connect to another component.
The PCB, from what I can find has:
- A Beken BK3231 bluetooth chip (Appears to be QFN36?), running off a 16MHz crystal (Best guess from text on top - P16 00M N FAB C)
- An unnamed 8 pin chip which connects to OBD2 pins 3 and 11, GND and another two pins off to the processor (Which I suspect might be TX/RX?). From what I can tell the rest of the pins go either to ground or power.
- An ELM327 processor under a heatsink blob (At least that's what I think those big black circles are?), which is not accessible for soldering.
- A chip labelled 8A825 which I suspect is a voltage regulator.
From this, what what would appear to be the best option for attempting to allow the Arduino to hook into this PCB and/or if anyone has any suggestions as to which pins might be a good place to start for TX/RX or other data protocols (UART/SPI/I2C)? I'm just starting out and wanting an opinion before I go and solder to something I shouldn't or completely stuff the PCB.
EDIT - The board
Bottom right is 8A825, top right is BK3231, middle is the serial converter?