# Assignment 11: Input Devices

## Learning outcomes:

• Demonstrate workflows used in sensing something with input device(s) and MCU board.

## Group assignment:

• Probe an input device(s)'s analog and digital signals.

• Document your work to the group work page and reflect on your individual page what you learned.

## Individual assignment:

• Measure something: add a sensor to a microcontroller board that you have designed and read it.

For this assignment I decided to make a device to measure the intensity of the light. For this I used a Phototransistor Flat Top Bk 1206.

In photometry, luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd), an SI base unit.

Step 1: I researched the sensor details.
PT15-21C / TR8 is a phototransistor in miniature SMD package which is molded in a clear water with flat top view lens. The device is Spectrally matched to visible and infrared emitting diode. Applications: miniature switch, counters and sorter, position sensor, infrared applied system.

Step 2: I designed the PCB card

Step 3: I exported the tracer and the interior of the PCB in .png format

Step 4: I milled the tracer of the PCB.

Step 5: I milled the interior of the PCB.

Step 6: Then I checked the conductivity of the PCB tracks using a multimeter.

Step 7: Then I prepared the following components to be soldiers to the PCB

Step 8: Then I soldered the components on the electronic card one by one.

Step 9: Then I checked the conductivity of the PCB tracks using a multimeter.

Step 10: I wrote the code to program the card in Arduino

# include <SoftwareSerial.h>
SoftwareSerial mySerial (0,2);

int sensorV = 3;

void setup () {
//mySerial.begin(9600);
mySerial.begin (9600);
}

void loop () {
mySerial.println ( "Mi valor:");
mySerial.println (sensorValue);
de retardo (70);
}

Step 11: I programmed the card using the USBtinyISP

Step 12 :Use the Arduino serial monitor to show the intensity variables of the light in the sensor

Step 13 :I checked the operation of the card by changing the intensity of the light