Assignment 2 - Working circuit

Working circuit with led and sensor

Crystal analog switch

I used Loes' examples as a reference for the crystal sensor. I soldered everything together like she had done before with hers. I tried using the thick copper steel but unfortunately I had nothing to break and bend it with so I had to use the thin copper wire which was hard to solder on the copper tape.

Back side crystal sensor, Dusanka, Loes, 2020

Front side crystal sensor, Dusanka, Loes, 2020

Then I connected the crystal sensor like I did before with the paper LEDs and button to the breadboard to see the outputs of the sensor. I used Loes' code.

I got really weird outputs in the beginning in the serial monitor, but this was because I didnt match the baud with the serial.begin and upload speed. After Loes told me this and I changed it the sensor was working!

Then I connected 2 LEDs with the sensor to make it a bit different than Loes' example and I changed the code a bit with an if/else statement.

Crystal sensor with 2 leds, dusanka, 2020

/*
  created by David Cuartielles
  modified 30 Aug 2011
  By Tom Igoe
  modified 13 March 2020 
  By Loes Bogers
  This example code is in the public domain.
  http://www.arduino.cc/en/Tutorial/AnalogInput
*/

int sensorPin = A0;    // select the input pin for the potentiometer
int ledPinRood = D1;      // select the pin for the LED that has PWM (~) e.g pin D1 on Node MCU
int sensorValue = 0;  // variable to store the value coming from the sensor
int mappedValue = 0;  //store the mapped values
int ledPinGroen = D2;

void setup() {

  // initialize serial communication with computer:
  Serial.begin(115200);     //make sure it matches with the number in the serial port

  // declare the ledPin as an OUTPUT:
  pinMode(ledPinRood, OUTPUT);
  pinMode(sensorPin, INPUT);
  pinMode(ledPinGroen, OUTPUT);
}

void loop() {
  delay(1000);
  // read the value from the sensor:
  sensorValue = analogRead(sensorPin);

//// FIND MIN & MAX RANGE FIRST, THEN COMMENT OUT
  // print values to serial to find lowest and highest values (min and max) in serial monitor
  Serial.println(sensorValue);      // met 10K voltage divider: bijv. range 100-850 zonder een fietslampje erbij (beter voor de video)
   
//PUT THE VALUES YOU FOUND (YOUR_MIN, YOUR_MAX) INTO THE LINE BELOW (line 36)
//put your min value and max value (as seen in the monitor) and map to a range 0- 255 for output
  mappedValue = map(sensorValue, 242, 1024, 0, 255); 

    // print values for debugging
    Serial.print("Old Value (no mapping) = ");
    Serial.print(sensorValue);
    Serial.print("\t");   // add a tab between the numbers
    Serial.print("New value (mapped) = ");
    Serial.println(mappedValue);

    if (sensorValue > 300) {
      digitalWrite (ledPinRood, HIGH);
      digitalWrite (ledPinGroen, LOW);
    }
      else {
        digitalWrite (ledPinRood, LOW);
        digitalWrite (ledPinGroen, HIGH);
      }
    }

If the sensor will catch light, the red led will go on and the green led is off and vice versa.

Then I tried to make the sensor in another kind of shape. Unfortunately because I understood the assignment a bit wrong and went so many ways because I didnt understood the circuit at first, I didn't had much time left for the actual creative part so I made a simple box. I would've loved to put more effort and time in this.

End result Paper circuit with sensor & 2 leds, dusanka, 2020

Box open = Red ON, green OFF Box closed = Green ON, red OFF.

Reflection

To be honest I'm not too proud of what I've made. It all took so much time because I couldn't understand how the circuits were working. I discovered that I was having trouble with understanding the assignment first, and then begin at the very first step. Instead of diving into the crystal sensor and being in a cycle of not understanding it. If I had started from the beginning I would've had more time left to make something nice. But I am happy that it is working at the end, it took a lot of time and patience.