Aircraft Keychain
The Idea
This project is one of those projects that began a while back. Shortly after we purchased our aircraft, I wondered if I could re-create the lighting used on the plane. I was also playing around with Atmel’s ATTiny 85 chips. These chips are small and do not have much RAM, speed, or GPIO pins, but that was ok for this project. During COVID, the ATTiny chips were about all you could get due to supply chain issues. I made a mock-up on a perf board (which I think I threw away, unfortunately) and then moved into KiCAD for the final schematic and board layout.
This design mimics the white strobe lights (flashing), Nav lights, tail light (pulsing), and rotating beacon (also pulsing). All of those are controlled by the ATTiny 85. Two 2032 coin cell batteries on the bottom power it. The landing light is directly tied to the batteries and is controlled with the push button. The power to everything else is through the slide switch.
All the files are on my GitHub page, which is linked below.
Teaching opportunity
Later I could use the board to help teach students to solder. When I did the board design, I purposely used both through hole and surface mount components, but used more significant surface mount components to make it a little easier for those learning. The “red” version of the board was a slight modification for use in my Make to Innovate program.
During an ISGC meeting, it was brought up on doing a soldering workshop as well. So, I took the aircraft design and made an ISGC version (that’s the board on the right). This version uses an all-through hole (except the battery holders) as it was targeted at a younger audience.
Future work
I do have ideas to improve on this including possibly swapping out the microcontroller and also making a version that would be all surface-mount (except maybe the landing light). But for now, I am pretty happy with how this board turned out.