We knew we wanted to teach people how to solder at RVA MakerFest. Estimates put the need at anywhere from 20 to 300 badges. We looked at various kits, but without knowing how many people we’d be teaching, they were simply too expensive, too complex, or not available in the needed quantity.
As the date drew closer, we still hadn't found a suitable board to use for teaching people how to solder. At (what seemed like) the last minute, we decided to design our own badge. Once the board was designed, there wasn't really time for a prototype run, so we crossed our fingers and ordered the full batch of PCBs from ITead.
It’s a very simple schematic, and the board can be soldered in less than 10 minutes, even without any prior soldering experience.
The circuit is about as simple as it can get, simply 2 LEDs in parallel with a battery. The current limiting resistors are omitted due to voltage drop and the internal resistance of the battery. We used blinking red LEDs due to the low forward voltage drop, but the blinking RGB LEDs can also work in this design and would probably last longer.
The schematic and board layout were created in Eagle CAD, and Itead provides a CAM job to create the gerbers. The most difficult step was creating the silk screen image. I followed a tutorial on Instructables called Adding Customer Graphics to EAGLE PCB Layouts. It took a few minutes of playing with the bitmap import settings to get it to look right.
I didn't consider the additional thickness from electroplating the through holes, so the pin didn't quite fit. It was possible to force it in with a pair of pliers, but it wasn't always successful, and just wouldn't work at the event. I ended up manually drilling each board with a 1/16 inch bit.
The pads for LEDs were also a bit small for beginners. They should have been enlarged a bit to make things easier.
The stainless steel pins are a real pain to solder. Maybe they should be glued or something else next time. The pins had a large (12mm) head. Headless pins would be a better choice. We’ll get started a bit earlier next year, and I hope to try a interesting board outline.
Of course, since there wasn't a prototype run, there were a few issues.
- The pin didn't fit.
- Pads were very small.
- The pin was very difficult to solder to the board.
The pads for LEDs were also a bit small for beginners. They should have been enlarged a bit to make things easier.
The stainless steel pins are a real pain to solder. Maybe they should be glued or something else next time. The pins had a large (12mm) head. Headless pins would be a better choice. We’ll get started a bit earlier next year, and I hope to try a interesting board outline.
No comments:
Post a Comment