First Project: Macro Board w/ RGB Strip


I've recently began using a drawing program that requires the use of macros / keyboard shortcuts to really be efficient. I use a Wacom tablet to draw with but due to my stature, reaching over the tablet to press the necessary keys is rather cumbersome and annoying.

My plan is to make a set of switches, preferably at least eight, that can be programmed to register as keys on your average keyboard. I don't need the keys to light up but I would like to add a RGB strip to the bottom of the piece, this strip will really only be a solid color or a fading / chasing rainbow effect (Whichever lends itself to be easier / simpler).

I would like to use Cherry MX Switches as I have a package of ten already. Otherwise everything else is up for grabs. If the switches I have aren't compatible then I am willing to replace them as well.

This being my first Arduino / Programming related project I figured it'd be best to come here for some assistance on what board(s) would be necessary and so on.

I've watched a few videos on how to make these boards but none showcase an added rgb light strip. I'm looking to keep this system as compact as possible as well.

Thanks, Erik

What you seem to be looking for is a HID (keyboard / mouse functionality). In which case e.g. an Arduino Leonardo (possibly too big), Arduino Micro or Sparkfun Pro Micro are some of the options.

For the LEDs, you can consider a WS2812B based strip. Note that every LED will draw 60 mA at full white; you can power only a few from the Arduino directly so you will probably be looking at an external power supply for the strip.

I'm not quite sure what Cherry MX switches are; although I have an idea, a link to a datasheet would be useful.

Integrating keyboard functionality and LED strip functionality is quite straight forward as long as you don't write blocking code. 1) Don't wait for a key to be pressed but just check the keys at a regular interval. 2) Don't use delays; this might mean that you have to rework the rainbow effect.

External power isn't an issue for me for the LEDs, would probably run it along side the usb connection inside a braided cable / sleeve of some sort.

I'm thinking I'll go with a solid color rather than the rainbow effect too. I plan to diffuse the LEDs with an opaque piece of plastic.

I've included some links, possibly to the correct datasheet you were looking for.

This youtube video covers using the same switches, though I'm not sure if this is the way I want to go with it as it looks like a lot of space could be conserved from the way he's set his board up.

This is the thingiverse page included with the youtube video.

I'm not entirely new to soldering / playing with electricity, though so far I've found myself totally lost in terms of how he's wiring these pins / connectors up. I do like the idea of the connectors as I see myself tinkering with the button layout in the future.

By the looks of it, he's using two-pin female dupont connectors on the cables; you can buy something like Wave Du Pont 2 Pin Female - Female - 200mm and cut them in halve if you don't want to make them yourself.

On the pcb, he probably uses IDC 2X16 Male Header - 2.54mm; on row will be connected to ground, the individual pin in the goes other row to one of the pins mentioned in the code.

The headers for the ProMicro are probably SIL 40 Way Header Female Connector

You'll need to find your own supplier and it might be cheaper elsewhere in the world; the cables cost roughly 0.40 us$.