The design files for the tracker board and more details on the design are in the later steps. This means that it can be fabricated on some incredibly cheap PCB fab' sites. The tracker is designed on a custom PCB which is 5 x 5 cm in size.
That means that we can't clock the '328 up to its full 16MHz but it will run happily at 8MHz on 3v3, and that's plenty for our purposes. Because the GPS module and SD card both require 3.3v and we have plenty of computing power, we may as well make the whole tracker run on 3v3.
We are going to make an "Arduino Compatible" board which we can program using the Arduino IDE.
The tracker is based upon the Atmel ATMeag328 Microcontroller which forms the heart of many of the popular "Arduino" boards. The guys at UKHAS are fantastically helpful. If you live elsewhere or you are doing this significantly after I write this instructable, please check the rules that apply to you. The approach I will use in this instructable is suitable for the UK under the rules prevailing in 2013. There are plenty of rules and regulations regarding what you can fly and which parts of the radio spectrum you can use for various tasks. That is what I will outline in this instructable. In order to take advantage of this wonderful network of helpers, we need to build a tracker that will communicate with their equipment. Fortunately, at least in the UK and increasingly across Europe, the very helpful guys at the UK High Altitude Society () have developed a distributed network of trackers who will receive a signal from your balloon, upload the data to a server and plot the position for you on a Google Maps based page (/tracker/). In order to see the photos that you have taken, you then need to find the camera afterwards. low pressure at the edge of the atmosphere) and then it will fall back to earth. This is easy enough: you attach it to a massive balloon, let it rise until the balloon bursts (due to the v. Ours went 38Km (124,000 feet) straight up. In order to take this kind of photo you need to send a camera up to the stratosphere. I'm having trouble embedding it so the link is here The Flickr set with the photos from our first launch is here: This is a quick-fire slideshow of the photos from the balloon, formatted as a 2.5 frames/sec video. That's not quite into space itself (100Km+) but so high that the sky looks black and you can start to see the curvature of the earth as the globe rolls away below you. One of the coolest projects I have done so-far with my kids is a "near-space" balloon.