Learn to solder with this Tinkercad badge! Attach a few parts to the custom circuit board and wear your glowing Peter Penguin pin with pride. If you are an educator, perhaps you picked up a kit at one of our event appearances.

Kit Inventory:

Peter Penguin printed circuit board (PCB)
Coincell battery and holder
Two slow color changing LEDs (if unavailable, here is a suggested replacement)
Tie tack aka pin back

The tools you'll need to build this badge:

Soldering iron and solder
Flush wire cutters
Tweezers (optional but handy)
Eye protection (optional but smart)
Helping third hand tool (optional but handy)
Heat resistant surface

The circuit board was designed in Autodesk EAGLE by Joshua Brooks. If you want to get your own PCB made, the board files are attached to this step. You can order your own board though sites like OSH Park. If you are curious about learning to design your own circuit boards in EAGLE, check out the free Instructables PCB design class.

Step 1: Attach Battery Holder

Heat up your soldering iron. If it's adjustable, set it to 650 degrees F / ~345 degrees C. Flip to the back of your PCB. Touch the hot tip of the soldering iron to one of the rectangular battery holder pads for a few seconds, then touch the solder wire to the spot where the iron meets the pad, feeding in a little more as it melts. Remove the solder wire but leave the iron in place for a few more seconds to flow the solder to evenly spread across the pad. Repeat with the other pad. The battery holder tabs should be placed on top of the solder pads (oriented according to the illustration on the board), and tape and/or a tool can be used to press it down while soldering. Firmly apply the soldering iron to the tabs’ junction with the solder pad to remelt the solder and flow it onto the battery holder to fix it in place. Let it cool for a few moments before continuing.

Step 2: Solder the Tie Tack

Insert the tie tack from front to back, lining up the tab to its own secondary hole on the PCB. Optionally tape it in place on the front, then lay it down on a heat-resistant surface. Touch the iron to both the tie tack and the metal plating around the PCB hole, then apply some solder to the joint. Keep the iron in place for a few seconds after removing the solder to allow it to flow evenly, then remove the heat. Allow to cool.

Step 3: Add LEDs

Insert the LEDs from front to back as well, but mind their orientation because LEDs are polarized! The longer legs are positive (+) and go in the top holes, as marked on the back of the PCB. Optionally use a third hand tool or some tape to hold the board and LEDs while you solder. Just like the tie tack, heat up the junction between the LED leg and the PCB plating before adding solder, then allow it to flow before removing the heat. Pro tip: solder just one of each LED’s legs first, then use your finger to press on the LED from the front side while you reheat the solder joint, and keep pressing until after you remove the heat. This will seat the LED nice and flush to the board. Then solder the other LED leg in place.

Step 4: Trim LED Legs Short

Use flush snips to trim off the LED legs at the back of the PCB. But be careful! The legs could go flying, so check your surroundings first, and consider holding the legs while you cut to prevent potential eye injury to yourself and others. Clean up the stray wire bits after you’re done.

Step 5: Install Battery

Slide your battery into the holder with the positive (+) side facing up. Your LEDs should light up and begin to slowly shift in color! If they don’t, one of your solder joints is likely incomplete (just reheat to flow and add more solder if needed), or your LEDs are in backwards.

Thanks for following along! Let us know your thoughts in the comments. You might be interested in these awesome resources for learning more: