Reading/writing SBEC3

[deadunitos-netizen]

Hi Daniel. Do you have a diagram of how to connect Arduino Mega2560 to OBD2 port, to read SBEC3 via SCI? I don't need diagnostics, just flash reading/writing. Thanks in advance.

[laszlodaniel]

Hi, check out this gist for a simple wiring and code example:
https://gist.github.com/laszlodaniel/9086006abcb726d0cee8bfde396f3de3

Ignore the logic inverter chip.
SBEC3 has normal UART logic and you can connect OBD2 SCI-bus pins directly to RX1/TX1 pins.
Additionally, add a 4.7k pullup resistor (to +5V) and a 100pF capacitor (to GND) for TX1.

Flash reading:
Use SCI 26 command in normal key-on mode.
More about this command and its parameter here:
https://chryslerccdsci.wordpress.com/sci-bus/

Flash writing requires putting the controller is bootstrap mode, generating a flash strobe voltage (+20V), and orchestrating flash block uploads to controller RAM, which I did not implement for ATmega2560.
More info:
https://chryslerccdsci.wordpress.com/2022/03/30/introduction-to-the-bootstrap-mode-of-the-sbec3-pcm/

You can find an early bootstrap implementation in the V1 scanner firmware:
https://github.com/laszlodaniel/ChryslerScanner/blob/master/Arduino/ChryslerCCDSCIScanner/ChryslerCCDSCIScanner.ino

[deadunitos-netizen]

Thank you very much.
"and orchestrating flash block uploads to controller RAM" - can you elaborate on this?

[laszlodaniel]

That's correct, flash writing sessions were never implemented in the Arduino framework.
I eventually moved on to the ESP32, where flashing works reliably (with Windows GUI and Android app).
If you'd rather not spend too much time figuring this out, I still have a few old V2.1.0 scanners I could let go for cheap.
But if you'd prefer to work it out yourself in Arduino, that's perfectly fine too.

[deadunitos-netizen]

I would love to buy it. But I'm from Russia. And shipping is difficult now. That's why I'm figuring out Arduino

[deadunitos-netizen]

Will I be able to build everything on ESP32 myself?

[laszlodaniel]

It's quite complicated to be honest. I see that you contacted Dino about his simpler implementation. Maybe you'll have better luck there. The ST M28F220 flash chip is generally supported by available worker functions.

[deadunitos-netizen]

Thank you for your help. I'll try his version. Maybe it will work) Soldering a flash drive from an ECU is not easy enough)