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Sunday, March 30, 2014

Dog exerciser...

Another ongoing project, a dog exerciser!
My dog loves to chase a laser pointer and needs regular exercise.
Built from:
-Arduino (duo)
-Custom sheild
-3d printed bracket and laser housing
-Micro servo from here:
-Home brew laser driver:  2N222 with laser connected in collector (+to 5v) and base connected through a 1k resistor to Arduino pin. Emitter to ground.
Laser diode with driver: Could use a laser pointer, this was easier and more rugged than taking a pointer apart and adding wires. Specs say it draws 25ma max mine measured at 15ma.
Current Features:
-Set the min and maxsweep-angle 
-Start and stop the sweep
-Laser turns on when sweep start, stops when it ends.
-Controlled from serial console, 
-BT Android app for remote control
-Pluggable BT radio so that I can use one radio and paring for many devices.
-Algorithm to adjust speed that is dependent on the angle. Insures that the linear speed is constant.
-Alarm to sound when laser starts, unit boots and on error.
-3D printed enclosure.
-Convert to a smaller Arduino like trinket
-A switch that my dog can activate
-A timer
Hint: I found that it is pretty easy to make a custom shield by taking perf board (RS) and solder pin segments just into the sections that you need for connection to the Arduino. If you do this right the board cannot- be installed wrong. I hate things that are not keyed.
As you will note this board becomes the mother board for the Arduino that plugs into it.  I leave the copper facing up and solder the parts on that side with solder bridges and wires in place of lands. I like that you can see the parts and wiring from the top making probing easy.
The only time that this is a problem is if you need all four connectors because one connector is not ion the same grid as the others (why did they do that?). In that case I cut a slot in the board with a Dremel saw and superglue the pin segment in the right place, then solder directly to the pin.