Step 13: Designing the electronics

For the main electronics, you'll want to familiarize yourself with Arduino, and also with the MAX7219 chips. More information about these can be found here for programming, or here for hardware and schematics.

To conserve space, I chose to work with SMD component ICs and design my own circuitboards in Cadsoft EAGLE PCB layout editor. This program can take some time to get used to, but there is a fairly powerful freeware version available for download. (pic 2)

After you've designed your circuitboards, export the gerber files to be made into boards. My boards were printed at BatchPCB.com. Each of the chips shown here can control one 8x8 matrixed LED array, so if you've got an 8x40 display like the one shown here, make sure to order 5 sets of boards and all components.

Components for your electronics can be bought from Digi-Key. Once all the boards come in, solder the components in place and use a multimeter to check all your connections. (pic 1)

If you're unfamiliar with SMD soldering, the video below is very helpful:

I also decided to add lighting to the ear areas and corners of the visor in my helmet. If you're comfortable plotting out an LED matrix, designing a simple I/O board like this will be a snap! (pics 3-6)

Remember that Arduino boards are designed to run in 3.3 or 5V, so design your boards accordingly. I chose to use an Arduino Yellowjacket (pic 8) (now discontinued, see the replacement RedBack here) as my controller, and a voltage regulator from Pololu to keep everything running the same voltage. (pic 7)

Materials needed:
  • Silver core fine-gauge solder (.015" diameter used in this tutorial)
  • Solder flux pen
  • Electrical components appropriate to your boards (resistors, capacitors, etc. See more details here)
  • LEDs
  • Circuitboards
Tools needed:
  • Soldering iron
  • Respirator for soldering
matthewf310 months ago

Hi, I was wondering if you could send more information about the electrical components and wiring. You have a caption that says "see more details here," but no link.


bwheat1 year ago
Very cool!! You did an amazing job on this!! You are exceptionally talented!
jrust13 years ago
Hello, im wondering if you can go into more detail about the voltage rating for the capacitors, or link to them? Thank you for the help in advanced.
Ezekana3 years ago
Yay! Thanks for adding the links to the programming and stuff!
Just the information I wanted in addition to your already-awesome process log. Thanks!