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Freematics OBDII is unable to upload.

Posted: Wed Dec 27, 2023 1:48 pm
by pensionsuey
Hi everyone!

After checking, I was unable to locate a special topic for introductions, etc. I love cars, but I'm also a tech geek. I bought the Freematics OBDII adapter with motion sensor a few years ago; based on the unpluggable cord, I think it is version 2.1. I recall testing it out a few times back to see if it could read and show the RPM and other data on my Nextion touch screen. It did function with a basic user interface.

My problem is that I am currently unable to communicate in any way with the Freematics. I see "USB-SERIAL CH340" listed in the device manager, but no matter what I tried—AVR Dudes, Arduino IDE, Freematics builder—it would always crash (through a USB connection). I'm attempting to figure out how to perhaps use USBasp to flash the Freematics, but I'm not sure what the board's connection pins are for. Can anyone help me with this?

Re: Freematics OBDII is unable to upload.

Posted: Wed Feb 28, 2024 8:53 am
by extremerotary
I don't believe you are able to update or access the firmware in that model at all. In the past, I have used a secondary chip (Arduino in my case), hooked it up via a UART connection, and then programmed the Arduino to communicate with the OBD chipset. That is my experience with both the OBD2UARTv1 and v2.1.
However, the FreematicsOne or plus or whatever actually has an Arduino chip on the board itself. So with that model you can plug it in to your computer and play around with the programming in the Arduino. I suspect/assume that the firmware for the ELM and CAN chips are still on the board, but likely stored in from PROM that we still cannot access. Hope that makes sense!