Make Your Own‎ > ‎


The microcontroller is a very important part of the sentry gun. It plugs into the computer via USB, drives the servo motors via PWM signal, and runs it's own code on-board to read commands from the computer and send commands to the servo motors.

Which Microcontroller: Arduino Uno or Sentry Controller?

Before you begin, you need to choose which microcontroller you will use. Here's a rough pro/con outline for each:

Arduino Uno:

  • Cheaper ($30)
  • Can be used for other projects later
  • More forgiving of incorrect wiring (built-in protection against reverse polarity)
  • You will need to do your own wiring

Sentry Controller (Standalone):

  • No wiring required, just plug in the servos and go
  • Smaller
  • Provides connections for the optional electric trigger function (allows you to wire directly to the motor of an electric airsoft gun, instead of using a trigger servo, for faster response time and reduced weight)
  • Provides connections for a reload switch, disable plate
  • Provides a servo power switch
  • Provides four indicator LED's: status, Rx, Tx, power
  • Pricier ($59)
  • Harder to use for other project later on


Arduino retailers around the world and online


Next step: Servos