My son’s surgery went very well. He is recovering nicely at home. He is doing well enough that we actually worked together on the AVC entry. Even with his jaw wired closed, he was a great help.
The temporary processor in the car is an Arduino Mini. I have added a LiPo boost converter to get the 5V and a mini SD memory card for data logging. I have attached an encoder to the transmission (12 counts per wheel rotation) and spliced into the electronic speed control signal to get throttle position.
We took this to the school parking lot and let the car rip. What we found is that the car can do just over 20 MPH and can accelerate to that speed in just over 2 seconds giving us a 1/3G acceleration. On the other hand, we can pull over 1G for a panic stop (full reverse throttle).
My son has a GoPro camera we mounted to the front of the car. Great fun to see the action from the car’s point of view. Including an interlude with a half curious and half scared dog. Here is a YouTube video (http://www.youtube.com/watch?v=ZQjqkYw-C7c).
At this point, my next goal is to ditch the Arduino. It just does not have the horsepower I want. I was finding that I could only get about 200ms polling loops when I started to use the “PulseIn” routine to log the signal from the electronic speed control. With the crazy turn rate of this car, 200ms is about 190 too much for tight control. Need to switch back to figuring out the whole Eclipse-Arm tool chain ‘thing’.
I also need to order a new 3 channel transmitter to have a spare channel for a servo mux. This will allow me to take over control from the processor should/when it does crazy.
I also started work on a Python based mission planning software package. Have the ability to put up a map of the area. I have a good car simulation and will now merge that into the GUI. Later I will add the telemetry from the car and the ability to replay log files.