DDD: Light

— Once in a while the DQI group at ID TU/e does a few days’ workshop: DQI Doing Days. This time we explored the design of complex systems through creating dynamic light objects that communicate. Three groups each created two objects that communicate either through their light behavior, wirelessly (through xBee’s) or both. We were asked to create functions in the arduino code that could be activated  by other light-objects. This workshop was organized by Remco Magielse and Serge Offermans of the Intelligent Lighting Institute. My group set out to create an object that would disrupt the behavior of the others’ objects, both through light and through xBee communication. We created two turrets, one with a light sensor and one with 3W LED’s. The turret with the sensor continuously searches for the lightest spot around it, telling the other turret where it is. The turret with the super bright LED’s will then turn in the same direction to ‘blind’ the brightest spot. (we assumed that other light-objects would also have light sensors and that delivering a bright light to them would then disable any of their behavior that would be based on varying light levels). In the end the behavior is a bit more surveillance than virus-like. The basic structure for the Arduino code enabling the xBee communication and remote function calling was given by the organizers of the course. On their blog, Serge and Remco have made a clear instruction on how to configure the xBee series 2 modules in API mode 2 mode. On the download page on their blog they provide links to all software, libraries and example code to start playing with xBee’s in an ad-hoc network.

The code for the Sensor-turret:
– scans half a sphere, at the end of a full scan, sends the servo-angles and brightness value of the brightest point to the Lamp-turret and points in that direction for a few seconds while increasing the brightness of the red led to a value relative to the maximum brightness detected.
– has several functions that can be called through xBee communication:

• scanning can be turned on and off;
• a number of scans can be requested;
• the servo’s can be set to a specific angle;
• the RGB led’s can be set to specific values;
• and servo and RGB led’s can be set in one command.

The code for the Lamp-turret:
– sets its servo’s to the angles received and the brightness of the LED’s (all colors) relative to the brightness value received.
– has several functions that can be called through xBee communication:

• the servo’s can be set to a specific angle;
• the RGB led’s can be set to specific values;
• and servo and RGB led’s can be set in one command.

The main materials used for the turrets:

• Arduino Uno
• Arduino multipurpose shield
• xBee module series 2
• 2x servo (Modelcraft RS-2)
• servo brackets and turret stands (lasercut, design by Joep Frens)
• LM1085 (adjustable voltage regulator) + circuit for 6 V: supply for servo’s

Sensor turret:

• Red, Green and Blue led’s (+resistors)
• LDR (+ resistor)

Lamp-turret:

• 3x LED driver
• 4x High Brightness RGB LED’s
• 4x reflector of cheapest Hema flashlight
• aluminum sheet