The bulk of this instructable is about creating the concrete base. There isn't much on the electronics - as there is so much already out there about using micros and LEDs.
Step 1: Making the Mould
- be heavy,
- have adjustable feet,
- have recessed panels for the controls and power,
- have integrated tubes that will accept the aluminium loops for the fabric form.
Tubes for the aluminium supports were held in place with short lengths of the aluminium rod (also keeps the concrete out). Nuts for the front panels and LED plate were also cast into the concrete.
Step 2: Pouring the Concrete
After pouring all the concrete, knock out the air bubbles with gentle hammer taps on the outside of the mould. I also tried vibrating the mould with an electric sander - but didn't notice much more bubbles appearing.
This step is important because otherwise the bubbles could make the finished piece look bad, or if a bubble was in an important place it could cause problems with mounting the plates.
Step 3: Inspecting the Cast
- tubes exposed for the fabric support loops
- central hole for reducing weight
- recessed front (and back) panels for controls/power
- recessed nuts for screwing led support panel
- I tapped the tubes so the screw in feet could be adjustable height for stability on uneven floors.
Step 4: Electronics
I didn't use a crystal, because I didn't need good timing - I used the on board RC oscillator.
I exposed the in circuit programming header on a parallel port connector for easy reprogramming.
The software is written in C, and will be available here soon. It reads 3 variable resistors for the controls and then writes PWM values to the transistors.
There are seven programs, selected by the right hand knob. The middle knob is intensity. For colour cycle programs the left knob is speed. For the colour creator program, the left knob is hue.