Part 14 – Building Sensors for your robot

Part 14 had us building a simple circuit to test for flame/heat/fire using a phototransistor. Before building the final phototransistor I put together a test using the breadboard. In addition to the breadboard test, I built a little IR emitter circuit that I would be able to use to test since I knew I was going to use this with my hack-a-toy. Here is my phototransistor test circuit. As well as the circuit reading working displaying values using the Arduino.

Photo resistor bread boarded

Test with the IR emitter.

The code that I used to monitor the photo resistor…

/* Program: lab14test
 *  creation: 1/30/2017
 *  author: Leslie Scott Kerfoot

#define myPhototrpin A0 // Pin for the photo resistor.
int myInput = 0; // Main loop variable to read the input.

void setup() {
  // put your setup code here, to run once:
  pinMode(myPhototrpin,INPUT);  // Setup the pin for input from the photoresistor.
  Serial.begin(9600); // Setup our serial/debug output.

void loop() {
  // Read the value
  myInput = analogRead(myPhototrpin); // Read the analog input

  // Print the value returned
  Serial.print(“Value “); 

Once I finished testing the values of the bread boarded photoresistor, I then created a finished sensor for use with my robot later. Here is the finished product nicely soldered and shrink tube wrapped.

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