this project should get you going for usb:
see thread here: Pi_dash - automotive (rally) dash written in Elixir and React that runs on Raspberry Pi - #2 by akoutmos
I’ve been meaning to get that project going over ble (cheap ELM327) with blue_heron - but haven’t had time…
Either way having an rpi0w for ble/nerves seems recommended at present…
A great trick is to use this special firmware on the rpi0w (Bluetooth with Nerves notes · GitHub) - which means you can plug it in to your main host and do the development on your main computer (mac in my case) and have rapid iterations etc. in figuring out the ble part…
