7-seg Display

A life-size 7-segment display visualizes the output of 2 artificial nueral networks

Key concepts/tech used: Arduino, p5.js, serial communication | In collaboration with: Mikian Musser

The Idea

My friend, Mikian, created an artificial neural network to recognize hand-written digits from the MNIST dataset. We thought it would be cool to visualize what the neural network outputs on a real-life seven segment.

Visual representation of Mikian's neural network

Building the 7-seg

via GIPHY

Communicating Through Serial

The p5.js serialport library was used to communicate between p5 program and Arduino. It works as follows:

1. The p5 program sends data to a p5 serial control application through a web socket
2. That application then sends the information it recieves to the computer's serial
3. The information in the serial is read by the Arduino
4. That data is interpreted and triggeres a certain binary-coded decimal combination to be triggered by the servos

Since we were sending in 1 second intervals, the serial port was sometimes filled with random information. To prevent this from affecting our visualization, we performed a simple error check only accepting input if they're between 0-9

setInterval(
    function(){
      console.log(numSent);
      serial.write((numSent)+"");
    }
    ,1000);
}

incomingByte = Serial.read();
incomingByte = incomingByte - '0';
delay(100);

if (incomingByte <= 9 && incomingByte>= 0) {
    setNum(incomingByte);
}

Sending and recieving in p5.js and Arduino

Encoding the data

int BCDToSS[16][7] = {
  {1,0,0,1,0,0,1}, // 0
  {0,0,0,0,1,1,1}, // 1
  {1,0,1,1,0,1,0}, // 2
  {1,0,0,1,1,1,0}, // 3
  {0,0,0,0,1,0,0}, // 4
  {1,1,0,1,1,0,0}, // 5
  {1,1,0,1,0,0,0}, // 6
  {1,0,0,0,1,1,1}, // 7
  {1,0,0,1,0,0,0}, // 8
  {1,0,0,1,1,0,0}, // 9
  {1,0,0,0,0,0,0}, // A
  {0,1,0,1,0,0,0}, // B
  {1,1,1,1,0,0,1}, // C
  {0,0,0,1,0,1,0}, // D
  {1,1,1,1,0,0,0}, // E
  {1,1,1,0,0,0,0}  // F
};

A basic decimal to binary-coded decimal encoder was used to translate the integer recieved by the Arduino into either on or off commands for each of the 7 servos. As a result, we could loop through 0-F.

Visualizing Neural Networks

We tested the final hardware on 2 different neural networks!