Apoapsis 2019

CanSat team of the Humboldt-Gymnasium Vaterstetten

Schematic and PCB Design

After some time full of exams and tests we finally got to take our next step: The PCB design.

Step 1: Circuit diagram

Before you start printing a PCB (Printed Circuit Board), you have to design a circuit diagram (or: schematic diagram) which includes all the components and electrical connections you need in a properly arranged schema.

Our first schematic
Our first schematic

It’s best to do it digitally, but it helps to have it all on paper as well. The design tool we used is the web application EasyEDA, with which you can also convert schematics to PCB designs. The electronics have been tested on breadboards before, so we could easily convert them into a schematic.

Our schematic: each box represents a layer in the CanSat
Our schematic: each box represents a layer in the CanSat

Step 2: PCB design

After creating your wiring diagram you can go over to the PCB design. Now you arrange all parts according to how it should look in the end. You also have to consider how to arrange them, especially if you don’t have a lot of space. We decided to design three different PCBs which will be stacked in the CanSat.

Our PCB design
Our PCB design

Step 3: Paper printout

This step is not really necessary, but before you spend a lot of money on something that doesn’t work in the end, it may be worth it to print the finished design out on cardboard. Of course you can’t test the electrical connections themselves, but you can see if all the components fit on the board the way you wanted them to. It’s especially helpful for us since we can arrange all three parts the way we want to connect them in that CanSat.

For testing: All three layers printed on cardboard
For testing: All three layers printed on cardboard

And now?

We’re almost done now. There are only a few things we want to optimize. For example, we want to see if we can save a little more space by rearranging the components. Also, it would be helpful to have three overlying holes with which we can connect the PCBs firmly together. And the antenna from the radio module could be connected to the top PCB, so the antenna would be on top of the CanSat instead of in the middle.

Written on 01. May 2018