dmxlive

Minimal livecoding environment for WLED over DMX

git clone https://github.com/llandsmeer/dmxlive
cd dmxlive
make

Open scene.js in your text editor of choice and edit the ip and nleds values to match your DMX server, then execute ./dmxlive. Whevener you update scene.js, dmxlive will reload the file allowing you to perform live coding.

// ip: nleds
wled_config = {
    "192.168.1.92": 150,
}

function color(i, t) {
    return i % 2 == 0 ? 0 : 255
}

The color function can return, any javascript value, and the program tries to make it into a color.

external input

Microphone support is optionally enabled with the ENABLE_AUDIO preprocessor flag, which is set by default. This depends on the OpenAL library. The ENABLE_MIDI flag enables midi support using the RtMdidi library.

sudo apt install libopenal-dev
sudo apt install librtmidi-dev

If these are not available, you can use make build/dmxlive.noaudio to build without input support.

For the moment, RMS microphone input is available as the global variable amp in scene.js. True RMS is a not a good measure of loudness, but I haven't gotten around to implementing something better.

Midi keypresses are available in global variables as:

# For button {keynum}, pressed at velocity {velocity} or 0 at key off
# Channel 0
k{keynum} = {velocity}

# Same, for channel n
n{n}k{keynum} = {velocity}

# For knob {controlnum}, at value {value}
# Channel 0
v{controlnum} = {value}

# Same, for channel n
n{n}v{controlnum} = {value}

# Examples
k44 = 127 # channel 0, key 44, pressed at full velocity
n1v1 = 64 # channel 1, knob 1, at 50%

some examples

A one-dimensional seashore

function color(i, t) {
    if (i > 100)
        return 'deepskyblue'
    else if (i > 50 + 10*sin(2*t))
        return 'aquamarine'
    else
        return 'sandybrown'
}

Draw a repeating rainbow

function color(i, t) {
    r = sin(0.5*i + 10*t)
    g = sin(0.5*i + 10*t + 2*PI/3)
    b = sin(0.5*i + 10*t + 4*PI/3)
    return [128+128*r, 128+128*g, 128+128*b]
}

Another way to draw a rainbow (10 repeats)

function color(i, t) {
    return hsv(i * 20 * PI / nleds + 5 * t)
}

Grayscale Kuramoto model with time-varying coupling coefficient

dt = 0.1
phase = []
frequency = []
for (i = 0; i < nleds; i++) {
    phase[i] = 2 * PI * random()
    frequency[i] = random()
}

function color(i, t) {
    K = 0.5 + 0.5 * sin(2*t)
    phase[i] += dt * (
        frequency[i] +
        K * sin(phase[(i+1)%nleds] - phase[i]) +
        K * sin(phase[(i-1+nleds)%nleds] - phase[i])
        )
    return 128 + 128 * sin(phase[i])
}

Volume meter

function color(i, t) {
    if (i > nleds * amp) return
    if (i > nleds * 0.8) return 'red'
    if (i > nleds * 0.5) return 'orange'
                         return 'green'
}

Visualize sounds over time in space

amax = 0
hist = []
function color(i, t) {
    if (i == nleds-1)
        hist[i] = hsv(t, 1, amp)
    else
        hist[i] = hist[i+1]
    return hist[nleds - i - 1]
}

Midi input

function color(i, t) {
    return [k44, v1, v2]
}

would not have been possible without:

• libe131
• duktape
• named colors from p5js
• libopenal
• librtmidi
• @max9901