Hmm, thanks for trying guys, but you're turning up the same kinda stuff that I am. What I want
(demanding aren't I?) is a prepackaged unit with I2C or some other serial communication just like the LidarLite, but with radio technology. A lot to ask? I don't think so.
This is likely an "Accurate, Range, Cheap: pick one" situation.
I disagree. Why?
Because radar sensors that easily fit this application are out there mass produced in commercial products. Check this guy out:
https://buy.garmin.com/en-US/US/into-sp ... html#/home
$200 USD, 140m, and works with cars out doors (varying environmental conditions, surface shapes, etc). Plus, I assume a good chunk of that $200 isn't in the radar sensor itself and is in the packaging, marketing, indication, and electronics interpreting the signal. I'm only asking for 30% of that distance, and of course cost relative to sensing distance is exponential, so it's likely possible to make a sensor much cheaper. And even the HB100 unit, which is just a dumb sensor, works 20m with similar technology and only costs $5. I don't think its a matter of the cost of the technology, and for my application accuracy isn't super critical. Even cost I'm willing to spend +$200. It's just a 'doesn't exist' issue.
I guess the issue is there just isn't demand enough for somebody to make a DIY radar sensor, which is probably true, but I don't see the demand for a LIDAR unit either and there's a whole tone of DIY LIDAR sensors.
I guess hacking an automotive unit is likely my best option, it's just not an easy job and I don't have a car with adaptive cruise control to reverse engineer the technology. I've read this thread:
http://diydrones.com/forum/topics/repur ... or-uav-ugv
And essentially I'd have to invest a lot of time into listening in on the communication between a car and the ACC unit to understand what commands to send. Something I'm willing to do if I had a car to mess with. Maybe one of my next rental cars will have ACC.