Documentation Errors/Confusion


I would like to suggest moving the external expansion connector information to the PINOUTS section. Or atleast fill out the expansion connector pinouts in the PINOUTS section to match as it is very confusing as is. You have to find the pins in the Automotive area and then find them in the pinouts area where they are spread out. Would be nicer to have it all in the same place and more professional.

Couple questions about the pinouts as documented for the expansion port.

Is there an error in the notes for pin 7?
It states ‘’‘K-LINE or LIN channel 1’’’.

But the schematics show K-LINE on pins PA10 & PA11 which is UART1, and L-LINE on pins PA12 & PA13 which is UART2.
They also show PD4 and PD5 going out to the external UART3 which would be correct and not showing them going anywhere else?

I am assuming the UART pins support 3.3v only.

Also for the following four supply voltage pins there are no amperage limitations listed, 19, 20, 23, 24.

Do they follow the total amperage limit of 1amp for the whole device? Or are they less? Also would the 5 volt and 3.3 volt outputs be limited to 1 amp as well since they might actually be able to serve a little higher amperage otherwise while keeping under the 1 amp at 12 volts. (Assuming the whole Volts * Amps = Wattage formula)

I have looked at the documentation for the external port as I consider wiring my Nextion 4.3" display to my M2’s to give me some feedback when I put them in car and not need the laptop to communicate.

The Nextion display only needs 250ma at 100% brightness at 5 volts. (Which would be more like 100ma at 12 volts plus any loss due to the voltage regulation used.). It appears it will also communicate at 3.3volts just fine so I should be able to just connect it to my M2 and drive it directly.


This is great feedback. Very much appreciated. We’ll be doing another documentation push here in the coming weeks and all of these points will be addressed, along with suggestions here:

If anyone else has any suggestions, feel free to post here, submit an issue/pull request on the documentation repo here:


Would be nice to see the ESP32 programming configurations for both Arduino IDE and the ESP-IDF shown in the docs as well.