Courtesy of CPT Hans.
I bought a USB-powered foam missile launcher, which has pan & tilt, and even a targeting laser! I'm powering it from the Trakr's internal USB port, and controlling it with the GPIO lines.
It has an IC that receives USB commands from the windows application and outputs control voltages on several different pins to control the motors, etc.
I'm going to use an H-bridge IC and a few transistors to accomplish the same task. It will certainly be much simpler than the 15 transistors, 20 resistors, and 9 capacitors that the original circuit contains!
I have all the wiring figured out, and have tested the control circuits...I'm just waiting on the H-bridge chips.
I wish the remote had more buttons. As it is now, you have to move into firing position, then stop and run the launcher app. The two joysticks on the remote control pan and tilt, button A toggles the laser on and off, and each press of button B fires a missile.
Since it's a stop-and-shoot situation rather than shoot-on-the-move, it's more like artillery than tank vs tank combat.