The Theory
For this project, the theory and examples shown in the the Servo Motor Control tutorial, as well as in the Infrared IR Receiver tutorial are heavily leveraged so be sure you have an understanding of those tutorials. Below I will briefly cover those two topics along with how Fire Control works for electrically firing the airsoft gun.
Fire Control
The circuit above shows you how one signal from the PIC 18F4520 can either turn the transistor on or off depending if a +5v signal (digital 1) is sent or a +0v signal (digital 0). When a +5v signal is sent the transistor is turned on, current flows through the transistor and the airsoft gun fires. When a +0v signal is sent, current does not flow through the transistor and so the gun does not fire since no power is present.
Servo Control
To control the servos, we need to create a specific 50 Hz signal like the one seen above. The way we will do this is by using the PIC 18F4520's timers. One timer will be used to keep the 50 Hz refresh signal and a second timer will be used to create the small 'pulse' signal telling the servo where it should move to.
Receiving IR Commands
When a button is pressed on a TV remote control it transmits a command over and over via Infrared Communication. The IR receiver module used in the schematic will filter and amplify this signal so that we can stand over 20-30 feet away from the receiver and the signal will still be clean.
For this project, the theory and examples shown in the the Servo Motor Control tutorial, as well as in the Infrared IR Receiver tutorial are heavily leveraged so be sure you have an understanding of those tutorials. Below I will briefly cover those two topics along with how Fire Control works for electrically firing the airsoft gun.
Fire Control
The circuit above shows you how one signal from the PIC 18F4520 can either turn the transistor on or off depending if a +5v signal (digital 1) is sent or a +0v signal (digital 0). When a +5v signal is sent the transistor is turned on, current flows through the transistor and the airsoft gun fires. When a +0v signal is sent, current does not flow through the transistor and so the gun does not fire since no power is present.
Servo Control
To control the servos, we need to create a specific 50 Hz signal like the one seen above. The way we will do this is by using the PIC 18F4520's timers. One timer will be used to keep the 50 Hz refresh signal and a second timer will be used to create the small 'pulse' signal telling the servo where it should move to.
Receiving IR Commands
When a button is pressed on a TV remote control it transmits a command over and over via Infrared Communication. The IR receiver module used in the schematic will filter and amplify this signal so that we can stand over 20-30 feet away from the receiver and the signal will still be clean.