Here is an example on how I build my dongle prototype. Note that this is not fitted in a real dongle case. It’s slightly too big for it and at the moment this my only ESP32 board and I want it removable. Also, I do like the RJ45 connectors (see this post) I use to hook up to the ZOE’s different CAN buses. In a follow up post I’ll show a more neatly “dongle-ized” evolution, with added LEDs, and maybe even able to access that second CANbus without any replugging.
The development board is plugged into two pin headers. When removed it reveals the DC-DC converter set to about 5.5 volt and the CANbus transceiver.