Methodology for designing/prototyping LED patterns

Question

Several of my projects go through this time-consuming and tedious phase:

1. design a LED pattern for a geometry of WS2812 LEDs
2. implement it with e.g. FastLED
3. write to Arduino and see results
4. goto step 1

The second step, implementing different ideas in C with FastLED (or similar) takes a lot longer than I'd like it to. How is this step usually solved? Are there higher-level software solutions? Specialised idea-testing hardware?

I'd like to easily try out ideas such as "what if these four LEDs blinked magenta every second, while a gradient was cycling around the gradient over here".

Answer 1

For designing patterns for visual evaluation, it would be better to just have the arduino/controller be a pass-through from something like a full computer. There is a project called FadeCandy, which allows one to send various patterns to a WS2812 chain using a protocol called Open Pixel Control.

Some options would be to build or buy a FadeCandy board, or to implement the OPC protocol on your own arduino so that you can play around with test patterns and designs in a rapid development environment like Python or just making the raw patterns in a file and dumping that to your device over the serial port or TPC, etc.

Once you have your patterns or design the way you want it, then you can translate it to C code and FastLED, knowing you have a fixed specification you are trying to implement, rather than reflashing an arduino for every iteration.

Answer 2

I'm not sure if there are already solutions for it (high chance there are, maybe in some DMX 'simulations'), however, it shouldn't be too difficult to make your own.

Use a programming language you like which can handle graphics, use the same data structure as you would with FastLed, and let the software program (you write) show the pixels on a screen. This means you don't need any Arduino code.

If you split the filling of the pixels and the showing of it on the screen, you can copy the resulting 'filling of the pixels' code on the Arduino.

Update Another solution, if you want to experiment with the actual WS2812, is to program all patterns you want to check with FastLed, and let inputs (via UART or fancy knobs/buttons/menu) decide what patterns (and properties) are executed. The key is to program the patterns in a flexible way (so use functions with parameters for each property, and states for which pattern(s) are executed or executed next if you want to check some sequence).