The Cash Riffle





Introduction: The Cash Riffle

Project overview

In this project you will learn how to make your self made money-shooter or how we like to call it "The Cash Riffle"!

What do you need?

  • Arduino kit
  • Motor Shield
  • HC-SR05 / HY-SRF05 Precision Ultrasonic Sensor
  • Power Supply 6V DC
  • DC motor 6V
  • Double-sided tape
  • UHU POR glue
  • MDF 3 mm
  • Rubber
  • 1.000.000 dollar (If you don't have so much money, you can print fake ones like we did)

Step 1: Lasercut the Cash Riffle Box

Take a 60cm by 30cm MDF 3mm sheet and place it in the Lasercutter. You can find a link down below to download the box template we used.

The box is easy to set up. It's designed in a way that the Arduino and breadbord are keeped seperated from the money and the motor.

Use some UHU-POR to glue the left part of the box togheter. This is the part where the money should shoot from the box.

Step 2: Lasercut the Wheel

Now download the template below and lasercut the wheels. Attach the wheels with some UHU-POR togheter and press the wheels togheter until the glue has dried. Cut some piece of the rubber and attach this to the double-sided tape. Use some UHU-POR on the wheel and attach it to the rubber.

Tip: If you want more grip, you can use a rubber band like we did.

Step 3: Assemble the Electric Circuit

Attach the motorshield on your Arduino and assemble the circuit using the supplied cables:


HC-SR05 / HY-SRF05 Precision Ultrasonic Sensor

  • VVC connection of the sensor attached to +5

  • GND connection of the sensor attached to ground

  • TRIG connection of the sensor attached to digital pin 8

  • ECHO connection of the sensor attached to digital pin 13

DC Motor

  • Red cable of the motor attached to PWR +
  • Black cable of the motor attached to PWR -

Step 4: Arduino Code

Copy the code below into the Arduino Software and attach the USB to your Arduino UNO


const int TRIG_PIN = 8;
const int ECHO_PIN = 13;

void setup() {

// initialize serial communication:


//Setup Channel A
pinMode(12, OUTPUT);

//Initiates Motor Channel A pin
pinMode(9, OUTPUT);


void loop() {
long duration, distanceCm, distanceIn;

// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
digitalWrite(TRIG_PIN, LOW);
digitalWrite(TRIG_PIN, HIGH);
digitalWrite(TRIG_PIN, LOW);
duration = pulseIn(ECHO_PIN,HIGH);

// convert the time into a distance
distanceCm = duration / 29.1 / 2 ;
distanceIn = duration / 74 / 2;

if (distanceCm <= 0){
Serial.println("Out of range");
} else if(distanceCm <= 100 && distanceCm >= 0){
Serial.println("motor AAN");
digitalWrite(12, HIGH);

//Establishes forward direction of Channel A
digitalWrite(9, HIGH);

//Disengage the Brake for Channel A
analogWrite(3, 255);

//Spins the motor on Channel A at full speed

delay(4000); }
else if(distanceCm >= 100){
Serial.println("motor UIT");
analogWrite(3, 0);

//Spins the motor on Channel A at full speed
Serial.print("in, ");
Serial.println(); }
delay(1000); }

End Code

Step 5: Put Everything in Place

Put the Arduino and all the cables in the box. Assemble the sensor in a way that fits your target direction. And finish the last things to complete the design of your box.

Step 6: Let the Fun Begin!

Place the Cash Riffle at a fun place... Hide yourself... and watch people surprise themselves when they walk in range of the Riffle.

Don't forget to tell your friends about this awesome project!!!

Have fun!



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    That's a fun idea :)