TheaterLightingAutomation

Controls theater lighting through Kodi connected to an Arduino.

Arduino Portion (LightFader)

This code is uploaded to an Arduino to PWM dim one or more lights. The intent is that the functionality is flexible enough to handle a number of circumstances. Channels are numbered from 0 to NUM_CHANNELS and can be assigned to any PWM-capable pin. The protocol is designed to be used between the Arduino and a software program, but everything is human-readable and connecting to the serial port with a terminal program will allow one to send commands and query status. Type help\n in the terminal to see a list of commands. Baud rate is 57600, 8 data bits, no parity bit, 1 stop bit.

Changing pins and channels

To modify the number of channels and which pin each channel points to, ensure that:

• NUM_CHANNELS is correct
• each channel[] element points to a valid PWM pin

The arrays for channels[], values[], fadeModes[], startTimes[], durations[], aValues[], and bValues[] are automatically zero-initialized and have elements as dictated by NUM_CHANNELS

Hardware

The hardware configuration for physically connecting to lighting can be simple or complicated. For testing, a simple resistor and LED work well. For LED strips or most other LED lighting a moderate transistor (e.g. Darlington, MOSFET) must be used. For other lighting such as incandescents more complicated circuits with triacs and diacs need to be assembled. In my setup I use two FQP30N06L N-channel MOSFETs and one TIP120 NPN Darlington array to allow me to use the 5-volt PWM signal to dim a 12-volt power source. The MOSFETs are good for 32 amps and 79 watts, and the Darlington is 5 amps and 65 watts, so each one should be able to dim a LOT of LEDs! Here are a couple example circuits for a single channel:

More info about using MOSFETs as switches can be found here. Remember that if you're using an inductive load instead of LEDs (like, say, controlling a cooling fan) you'll need to put a flyback diode in parallel with it.

Kodi Add-on (script.service.ke4ukz.theaterlightingautomation)

This service allows for control of lights (and possibly other devices) by sending commands over a serial port when playback events occur. Almost all parameters are user-configurable, from whether or not to even fade to the fade duration and lighting levels. Currently three lighting channels can be controlled: house, aisle, and ambient. While designed to work on a Raspberry Pi running raspbmc or OSMC, there shouldn't be any reason it won't work on other systems as well (I do my testing on Kodi 14.2 on Windows 7).

Configurable Settings (in Kodi)

• Serial port and speed
• Dim on pause
• Dim on screensaver
• Fade duration
• Independent selection for controlling house, aisle, and ambient lighting
• Light channel for each house, aisle, and ambient
• Normal lighting level for house, aisle, and ambient
• Playing lighting level for house, aisle, and ambient
• Paused lighting level for house, aisle, and ambient
• Screensaver lighting level for house, aisle, and ambient