I've updated the GeoCrawler 2 (Lego UAV) instruction page. It now has a list of steps and parts necessary to complete the compass-sensor version of the UAV. The GPS version software is still in development. That should be ready later this summer.
I've switched GeoCrawler 1 (Picopilot UAV) to a more appropriate airframe. It's now flying on a Mini-Telemaster (shown), which is an inherently stable 3-channel trainer. We may someday move back to the Predator airframe, but we need to ensure the autopilot is rock-solid before putting it in a more challenging airframe.
Development on GeoCrawler 3 (cellphone-based UAV) is now in the alpha software stage. The code is able to control the servo and read the GPS coordinates from the phone. Now working on parsing the SMS command set and turning heading information into rudder commands. At a later stage we'll incorporate a GPS-based altitude hold by using the phone to control the throttle as well. Yes, I know GPS altitude readings are pretty approximate, but if you average them over time it's good enough for the +-10m that we need.
I'm working on a new pan-tilt gimbal for GeoCrawler 1. Because the plane is smaller than GeoCrawler 2, it will be made out of aluminum and modeled after this simple Lynxmotion design (but for micro servos, not standard size)
We lost our flying field at the Alameda airfield due to environmental remediation. Now scouting new airfields in the Bay Area.