Mini Laser Light Show on an 08M2

[BobMcNobby]

Hi Peter, I have looked into the Galvo idea, I couldnt find any cheap galvo's and since servos were going to be too slow I opted to reinvent the wheel but on a much smaller scale, the idea being "if the PCB is small and light it could mount anywhere !", I was thinking of attaching it to the end of a guitar or something similar

Also new ideas being explored :
PAN - Make the PCB circular and mount 3 motors equispaced at the periphery. mount them pointing down but at a slight angle out, then place the PCB on something round so that the 3 motors (with silicone sleeving on shaft) drive round the top of the round object. this will give 360 degrees continuous rotation
TILT - mount a third (larger) square mirror at an angle to the beam output which is on a pivot and drive it by a tiny motor. may get up to 60 degrees tilt out of that

I am also looking into 1-wire bi-directional H bridge to drive motors, there is probably something on here about that

Bob

 

[BobMcNobby]

Current update :

Been working very hard on this project and have working software & hardware with great displays just like my purchased "Crab" laser but 1/10 of size & weight !

After deliberation decided to drive motors directly from micro pins as they only take 18ma max !!
Created my own 2 channel PWM in software
Laser diode also driven from micro so that I can switch it on/off/strobe

Very Happy with the results !

 

[RexLan]

Make a video ... post it up and we can see it in action!

 

[Paix]

With small light pieces of acrylic mirror is it viable to pivot the mirrors about their centre and use linear actuators to drive them? Driven at right angles to each other, the first mirror would drive the X axis which would reflect off the second mirror driving the spot (scan) from the first mirror in the Y direction. The Z (on off) modulation of the laser light source producing the image.

Now I know nothing about lasers or linear actuators, but am exceedingly interested in the whole concept nonetheless.

 

[BobMcNobby]

Hi Paix, you are probably right and normally manufacturers use Galvanometers with mirrors connected (as you suggested)
My project was cost and size driven, and so far I got a working laser light show working for about £5 of parts

Stay tuned for more as I progress !

 

[BobMcNobby]

UPDATE:

Just added a third tiny motor & 20mm mirror combination, this allows me to change the position of the final laser output in a 90 degree arc, I only pulse the motor very briefly to create a new position and the position is basically random, its a bit like a stepper motor

Also added strobing, and timed-on times for the laser diode

The software is quite complex now
It understands volume levels and extracts bass drum beat (partly with software)
Sequences 2 motor/mirror combinations to give different patterns
Switches motors and laser off when quiet
Drives 3rd positioning mirror/motor combination

So far still only drawing less than 100ma at full tilt

and STILL using picaxe 08m2 !

I have basically run out of outputs, but my next task is to try and implement one-wire motor direction drive using a pin that is already used for something else !!

Bob