Automatic Load mode (SM mode)
Posted: Thu Oct 25, 2012 12:57 am
I had a thought about the whole firmware loading process. Having to set a jumper or flip a switch to get into SM mode and load firmware can be a bit of a hassle, especially when you either have a lot of wires between you and your switch/jumper, or the ECU is in an inconvenient location. I haven't gotten around to putting wires and a switch on the header pins for mine, so it is still a hassle. Why not take the Arduino approach? The FTDI chip allows for full control of the DTR line, so instead of tying the SM pin to high via a jumper or switch to enter SM mode, you tie it to DTR. Then your appropriate loader application would:
* While running in firmware mode...
* Set DTR high
* Send a FW reset command (Assuming this does a full reset, and allows it to check for the SM pin)
* Now in SM mode, load firmware
* Set DTR low
* Send SM reset command
* New firmware loaded!
What do you all think? This totally eliminates the "oops, I accidentally left it in SM mode again, gotta unbolt my ECU to unset the jumper" issue that some of us may encounter at some point in the future, or have encountered before.
* While running in firmware mode...
* Set DTR high
* Send a FW reset command (Assuming this does a full reset, and allows it to check for the SM pin)
* Now in SM mode, load firmware
* Set DTR low
* Send SM reset command
* New firmware loaded!
What do you all think? This totally eliminates the "oops, I accidentally left it in SM mode again, gotta unbolt my ECU to unset the jumper" issue that some of us may encounter at some point in the future, or have encountered before.