Author: Jacob Smith -
Welcome back to my balloon blog. You’ll be glad to hear I have been very busy with this project over the last couple of months - testing the cameras, finalising and testing the tracking device, and modifying a polystyrene box to house all the components…a lot of things to talk about! I’ll split this up into two posts – up first is the tracker and cameras.
There’s no going back now
Having designed and successfully tested the electronic circuit for the tracking system, it was time to transfer the components to a stripboard and solder them in position. On a stripboard, parallel copper tracks run along the width on the underside of the board. Current will flow along a track and may be stopped at certain points by cutting the copper track, allowing flexibility in the creation of circuits. The point of this is to create a more robust circuit by soldering wires giving them less chance of coming loose during flight, which could result in the tracker not working. Also, by including a row of ‘header pins’ along the two lengths of the board I would be able to simply plug the circuit into the Arduino.
It took a few weeks to get the components all positioned in a way that I thought would work, after which time I took the brave step to start soldering knowing that it would be difficult to go back if there were big errors in my judgement. Having never used a stripboard before this was highly likely! Unsurprisingly I had a few issues when it came to providing power to my circuit…a short circuit, the smell of burning...but thankfully nothing that I couldn’t quickly fix without having to start again. Below is the finished circuit.
Camera set-up and testing
In my last post I introduced the cameras that I would be using, a Lightdow action camera for taking video, and a Canon PowerShot for stills. Finding a power bank to power the action camera was a challenge in balancing battery capacity with mass, as throughout the design of a balloon payload it is important to minimise mass wherever possible. The one that I settled on performed extremely well as you will see in the video below, as did the Energizer Ultimate Lithium batteries used to power the camera and tracker.
I have successfully added the Canon Hack Development Kit to the SD card in the Canon camera, which allows the camera to run various scripts to add more functionality. I will run the basic ‘take a picture every 5 seconds’ script. The Canon and video camera will both use the same size and class SD card - 32GB size as I want to store a lot of data, and Type 10 class which is fastest data writing speed for an SD card.
Testing is a vital part of any engineering - it allows you to see if you have actually made what you think you've made, and to discover any unforeseen issues. I operated the cameras and tracker for longer than I hope the flight will be, giving me confidence that they will perform adequately on the real flight. Watch the video below to see all the testing in action…
Thanks for reading - read part two to find out how I will house all the components and how I got on with a much larger scale test of the tracking system.