I've been working on adapting my Vector display code to run on an RGB laser projector with mirror galvos.
Board says "LanLing DmxMain PCB 1.03 2011-06-25". CPU is a STC 89C58RD+, an 8051 with 32KB and 16KB of EPROM.
ULN2803APG - 8 darlington transistor array
LM358P - Dual opamp, likely for the audio input. second one's purpose is unknown.
- SN75176SB - Differential bus transciever, for the DMX interface
- LM705 - 5V voltage regulator for CPU
Green laser: 17 P3.7
Red laser: 16 P3.6
- Blue laser: 15 P3.5
- Steppers: 8 wires, 21-28 into a resistor pack then into darlington array. Common pin is always at 12V. This is a unipolar setup; arduino tutorial on driving. Can drive with half steps.
Teensy 3 can drive steppers and PWM for the laser control. Brightness values around
analogWrite(3) are still pretty bright. Steppers seem ok with half steps up to about 600uS between pulses. Only 64x64 display is possible at this range of angles.
The 10Kpps galvos are not quite fast enough for MAME games. Asteroids is nearly playable, but not very distinct. We'll see how the 30K galvos work instead.