Automatic Load mode (SM mode)

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malcom2073
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Automatic Load mode (SM mode)

Post by malcom2073 »

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.
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Fred
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Re: Automatic Load mode (SM mode)

Post by Fred »

You're far from the first to suggest it, and definitely won't be the last. It's easy enough to hack this into a bench setup, where it's useful, or for a hacker to hack it onto their car, however I'll cut off my dick before I endorse any software or hardware that allows this functionality to be used mainstream. It's simply not appropriate to allow that interaction to occur in the general case for safety reasons.

As for convenience, we're not too far away from the time when you load up one fw version, tune it, and forget it. This is the common case. Most people put on a version and roll with it. Even now. I have to beg to get people to upgrade, otherwise they just keep driving around. And no, it's not because of a jumper/switch. It's the whole hassle of getting a computer, attaching a cable, finding files, verifying tune, etc etc. Plus the fact that the firmware that they already have "just works", which is the point.

Just for example, I had a pre-alpha 2.0 MS2Extra version on my truck for ~4 years and never upgraded it. Well, until I sold it and put a superior system in its place, that is :-)

In other words, it's dangerous, only useful to devs/hackers/testers, and firmware upload should stay a very deliberate thing.

Arduino is a toy, this is real life.

Fred.
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