Small python web DMX Controller for Raspberry Pi 3

Edit file

$ sudo nano /home/pi/.config/lxsession/LXDE-pi/autostart

To be :

@xset s noblank
@xset s off
@xset –dpms
@chromium-browser --kiosk --app=http://localhost:5000/?raspberrypi=true

A program is a set of channels associated to expressions.

Channels and values are based on evil eval where elapsed(step=0) is time in seconds.

Using values higer than zero for step will quantize time accordingly, allowing step changes.

Each frame, values are computed according to selected program and expressions.

Functions available :

• cos2(x) : math.cos expressed between 0.0 and 1.0, to avoid negative values
• sin2(x) : math.sin expressed between 0.0 and 1.0, to avoid negative values
• randint(min, max, step=0) : random.randint where elapsed(step) is used to seed the random generator
• choice(iterable, step=0) : random.choice where elapsed(step) is used to seed the random generator
• lerp(start, end, factor) : performs a linear interpolation from start to end, given the factor

Universe expressions are not reset each program change, which means that for blackout you need to assign "0" to all relevant channels

This allows to fire specific fixtures without affecting other fixtures (see Smoke on / off in example)

Expressions are computed in float from 0.0 to 1.0, except if the expression starts with $. Then, expression ranges from int 0 to 255

This allows to express precise values for specific fixture programs (see Absolute values in example)

Spaces are not allowed in program names but underscores are replaced with spaces in UI captions

{
    "Blackout": {
        "range(1, 256)": "0"
    },
    "Color_rotation" : {
        "1": "0.5 * math.cos(elapsed * math.pi * 0.25) + 0.5",
        "2": "0.5 * math.cos(elapsed * math.pi * 0.25 + math.pi) + 0.5",
        "3": "1.0 if elapsed % 1 > 0.5 else 0.0"
    },
    "Strobe": {
        "range(1, 4)": "1.0 if elapsed % .1 > 0.05 else 0.0"
    },
    "Smoke_on": {
        "16": "1"
    },
    "Smoke_off": {
        "16": "0"
    },
    "Absolute_values" : {
        "1": "$128",
        "2": "cos2(elapsed)",
        "3": "sin2(elapsed)"
  }
}