The next project is a set of car gauges. I’ve taken apart an ELM327 mini obd2 adapter, and removed the bluetooth board. For testing I have this hooked up to a cp2102 usb to serial breakout and am talking to it with a serial terminal. Power is soldered on to the board and provided by a 12V wall wart. The next step is to hook it up to an esp8266 (esp-12) that can drive a bunch of oled displays. (see the previous post). I won’t be using the wifi on the esp board, but the module is just so handy that it seems a logical choice. I get 3.3v off of the ELM327 dongle, so it it just four wires from the dongle to the gauges.
The dongle talks at 38400, eg:
>01 SEARCHING... UNABLE TO CONNECT >ATZ ELM327 v1.5 >atrv 11.9