Arduino Ball Gun with ADXL335

A small project I built in 2015 to test an acceleration sensor with my Arduino Mega 2560. The pitch, roll, and yaw of the gun are controlled with the ADXL335 sensor.

Parts

• Arduino Mega 2560
  
• Acceleration Sensor ADXL335
  
• Motordriver L293D
  
• Lego Technic Power functions M-Motor
  
• Two Servos

Circuit

In the following picture you can see the electrical circuit of the ball gun.

Code for Arduino

// import the servo library
#include <Servo.h>

// Outputs
Servo servoPlattform; // servo for vertical tilt
Servo servoRot;       // servo for rotation
int moShot_a = 10;
int moShot_b = 11;

// Inputs
int zAccPin = 2;
int yAccPin = 1;
int xAccPin = 0;

// Variables
int posServoPlatt = 1500;
int posServoRot = 1500;
int zAcc = 0;
int yAcc = 0;
int xAcc = 0;

void setup() 
{ 
  // Outputs
  pinMode(10,OUTPUT);
  pinMode(11,OUTPUT);
  
  // Attach servo variables to pins
  servoPlattform.attach(2);
  servoRot.attach(6);
  
  // servos to middle position 
  servoPlattform.write(posServoPlatt);
  servoRot.write(posServoRot);
  
  Serial.begin(9600);
} 
  
void loop() 
{
  analogWrite(moShot_a,0);
  analogWrite(moShot_b,0);
  while(true){
    // Check values of the acceleration sensor
    zAcc = analogRead(zAccPin);
    yAcc = analogRead(yAccPin);
    xAcc = analogRead(xAccPin);
    zAcc = zAcc * 0.1;
    yAcc = yAcc * 0.1;
    xAcc = xAcc * 0.1;
    // print values 
    Serial.print("  z: ");
    Serial.print(zAcc);
    Serial.print("  y: ");
    Serial.print(yAcc);
    Serial.print("  x: ");
    Serial.print(xAcc);
    Serial.println();
    // control the vertical tilt 
    if(yAcc < 28 &amp;&amp; posServoPlatt <= 2200){
      posServoPlatt = posServoPlatt + 10;
      Serial.println(posServoPlatt);
    }
    else if(yAcc > 34 &amp;&amp; posServoPlatt >= 1000){
      posServoPlatt = posServoPlatt - 10;
      Serial.print(posServoPlatt);
    }
    servoPlattform.writeMicroseconds(posServoPlatt);
    // control the rotation
    if(zAcc > 34 &amp;&amp; posServoRot <= 2400){
      posServoRot = posServoRot + 10;
      Serial.println(posServoRot);
    }
    else if(zAcc < 28 &amp;&amp; posServoRot >= 700){
      posServoRot = posServoRot - 10;
      Serial.print(posServoRot);
    }
    servoRot.writeMicroseconds(posServoRot);
    // shot ball
    if(xAcc > 50){
      analogWrite(moShot_a,255);
      analogWrite(moShot_b,0);
      delay(650);
      analogWrite(moShot_a,0);
      analogWrite(moShot_b,0);
    }   
    delay(5);    
  }
}