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The project is an electronic trigger for my paintball gun. It was a learning project and I learnt, but learning is a journey not a destination, this project is over bar the mechanical integration, but I am still learning.

Here is the schematic of the board, I used Eagle to design it, and it to learn how to use Eagle. The PIC is a 16F627, using the "High Speed" ("HS") clock setting, the crystal is 19.8806 as it divides nicely into round numbers when using TMR0.

The jumpers are not going to have pins, they are solder points for external components and used as follows

  • JP1-Power, a 9v battery (PP3) in series with a slide switch
  • JP2-Trigger, a snap switch for detecting the trigger pull
  • JP3-Solenoid, a connection to the solenoid that releases the sear, initiating the firing process
  • JP4-Spare, this is a digital output that will be used to activate the agitating hopper. A future project

The resistor, R3 is sized specifically for the solenoid, as is the transistor T1 (a KSC5019MTA from Fairchild). The solenoid takes about 1.3A to energize.

Schematic for the trigger

This work is copyright Anthony Toft, 2004