"Hybrid Hand Throttle/Cruise Control" would be a more accurate title, but I didn't want to imply hybrid
vehicle involvement.
Basically, I'm contemplating a device that would primarily be an electronic hand throttle, but which would also have aspects of a cruise control. The intent is DWL with limits, so one's speed will stay above a set minimum for highway travel for example. It will
not be a traditional cruise control; speed would be set by a control on the unit, not with the accelerator and a SET button.
Normally I wouldn't bring this up until I had something to show, but I wanted to gauge interest. That's because I'd typically do something like this in 8051 assembly language, or even on a PIC processor given sufficient horsepower. But it seems like Arduino is the preferred DIY platform these days, so I'm thinking maybe I should go that way. It doesn't matter to me which I use, but if open sourcing it on a common platform might give others a building block or starting point to work from, why not?
So: Would anyone be interested in such a thing? No promises: I have no idea how long this will take or if I'll even do it; I'm just evaluating right now. But to show it's not purely a mental exercise, here's a snapshot showing the VSS signal from the CARDIS at 55 MPH:
Image by Rick Rae on Flickr
Clearly, I'm at least serious enough about this to have found and tapped the VSS signal, rigged up my scope on an inverter, and done a quick test drive to gather some data. (Sorry for the blurry image; a cruddy cell phone camera plus taking photos while driving at speed rarely equals high quality! I was taking snapshots because mine isn't a storage scope, and pictures were faster than setting up the data acquisition system on the laptop. Sharing an image with fellow EMers was purely an afterthought.)
Thoughts invited, and thanks!
Rick
P.S. To any engineer types reading this, don't let the grungy waveform concern you. I was using a distant ground so the scope was showing all manner of noise that wasn't really there. All I cared about was getting the pulse timing for a few different speeds.