This is part of a series of blog posts in which I show you how I develop a DIY FPV diversity controller. In this step I have printed the first circuit to a cardboard. I use it to test fit the ATtiny85 micro controller, the 4066 electronic switch and the other components. Read more below…
The first image shows the circuit board in 1:1 scale printed to a piece of cardboard. Note that I printed to the top of the cardboard so that I can better show you the details. In real the whole circuit would be on the bottom of the PCB. The whole thing is designed to use a single layer PCB. As all the components I use are through-hole components the circuit will be on the bottom.
The picture shows the printout of the toner mask that I will use to create the first test PCB. So everything that’s black here will be copper on the real PCB. This is exactly the circuit that I showed you in the previous step. You can find the eagle files here.
As you can see the PCB layout is perfect. Everything fits snugly but there is still enough room to run all the traces and to make soldering easy. Note: In real the trace will obviously run on the bottom side of the PCB. I just printed on the top for this test.
PS: Just in case you are wondering, those are not the correct resistors for the LEDs. For the test fitting I just grabbed the first two resistors I had laying around 🙂
At the moment I’m having a bit of trouble to get the toner transfer to work. Either the toner does not transfer to the copper correctly or the toner melts too much and blurs so that no traces are left after the transfer. I need to experiment more before I can fabricate the first test PCB …
Visit http://bitbucket.org/rgruber/fpv-diversity for all resources of this project.
You can find the source code, diagrams and photos there.