Twice this year I walked around for more than an hour flying a kite-lofted camera that I thought was taking photos, when in fact it was just fooling me into getting exercise. On the first occasion the shutter controller battery died, and the other time the camera just got confused and stopped shooting. I think I sent radio commands to shoot too frequently and it decided to take a nap. This happened another time as well but I happened to reel everything down after only 20 minutes of not taking photos while I was jogging here and there. I have modified the controller so the battery lasts much longer, and I have learned to be patient when sending radio commands, but I am certain that the rather fragile KAP rig electronics will surprise me again with their unexpected inactivity. So I have been looking for a way to monitor the camera operation from the ground. I have been brainstorming with some friends about how to do this, and Don Blair, a physics graduate student at UMass has been prototyping an alert system based on a $20 pair of walkie-talkies. I couldn’t stand hearing about all the fun he was having in Amherst using MOSFETs to remotely push the walkie-talkie PTT button, so I decided to build my own solution. Continue reading “Downlink”