Evil Genius Labs
Custom Electronic Art
Custom Electronic Art
I’m preparing to exhibit at Maker Faire Kansas City 2017, and trying to come up with an interactive and educational project for people to play with.
With what I have on hand, I quickly threw together a couple of breadboards, each with a Teensy, some RGB LEDs, and three potentiometers (using Paul Stoffregen’s excellent Sturdy Potentiometer Adapter for Breadboards).
While this would work, it’s not very durable. I need something that lots of people can tinker and play with all weekend, without worrying about replacing disconnected wires.
So, I set out to design a PCB that I can assemble ahead of time, and will hopefully be durable enough to last all weekend. It will also have the bonus of being a tutorial project I can use in classes, workshops, and share online.
With these goals in mind, I created this PCB.
The switch will change the potentiometers from controlling RGB to HSV. The PCB includes the NeoPixel “best practices” capacitor and resistor, and pins to connect more LEDs (a strip, ring, etc). The tactile momentary push button could be used to change modes, from the tutorial to patterns, animations, etc.
The mounting holes below the Teensy LC will allow the PCBs to be mounted on a board, so they don’t fall off the table or “walk away”.
|NeoPixel Stick 8x||1||$5.95||$5.95||Adafruit|
|SPDT Slide Switch||1||$0.95||$0.95||Adafruit|
|Tactile Button (6mm)||1||$0.25||$0.25||Adafruit|
|10k Linear Pot||3||$0.83||$2.49||Digi-Key|
|330 Ohm Resistor||1||$0.10||$0.10||Digi-Key|
|10K Ohm Resistor||1||$0.10||$0.10||Digi-Key|
In an effort to minimize the parts cost, while maintaining the ease of assembly and use, I initially thought about using a 5V Trinket. They’re inexpensive, but still high quality, and won’t require a level shifter. They just don’t have enough inputs, so I switched to the 5V Pro Trinket. Then I remembered the Teensy LC, which is less than $2 more, has a 5V digital output pin, faster processor, more RAM, FLASH, etc. It can also be ordered from OSH Park with the PCB. I was also warned by several people that the upload process for the Trinket can be frustrating.
I created a simple Arduino sketch to show how RGB & HSV work to combine to create different colors. I also included a rainbow pattern that is displayed when the momentary tactile button is held pressed.
More details coming soon…