Signal Fish Tutorial: Circuit design

Version 7

    There are a lot of parts that make a Signal Fish fly. Every component plays its part. Additionally, every piece adds additional weight to the overall rig. This is important; in order for our balloon to get off of the ground (literally!), we needed to account for the weight of every piece.

    Rather than having to have the rig physically attached to the balloon during development, we separately weighed the constructed circuit with all the components attached, including pin headers, wires, batteries, everything! It is vital to get an accurate measurement before attaching everything, so we used a bottle filled with water that matched the weight.

    The whole point was to see how much weight the inflated balloon could take. We added and removed water from the bottle and weighed it repeatedly until the Mylar balloon was able to lift the bottle off the ground. Knowing how much weight the balloon could take gave us a clearer choice of whether we wanted a bigger balloon or could swap for lighter components. This enabled us to experiment with components and not disturb the balance needed to keep the balloon afloat.

    Here is the completed circuit diagram for the modules on our rig:

    Signal Fish diagram.png

    Most of the modules we’re using don’t work on their own out of the box. They require external libraries that we import so we can compile them all together. Instructions for installing libraries can be found here: The modules we’re using require the following libraries:



    Check out the open sourced project here: InsideTheBlue/signal-fish · GitHub


    < Putting it all together

    Part 1: XBee configuration
    Part 2: Rig construction
    Part 3: Circuit
    • Circuit design