Phototransistor arduino resistor tester - Using a Photocell Photocells Adafruit Learning System
One of the applications of the IR emitter and IR phototransistor is a photoreflector. Different resistor values affect the sensitivity of the infrared.
The HCPL0531 dual channel optocoupler contains a times that of a conventional phototransistor coupler by TTL load and a 5. 6 k ohm pullup resistor.
sampling resistor of such a value that voltage dropped phototransistor Measurement Techniques
Blink. This example shows the simplest thing you can do with an Arduino or Genuino to see where you connect one end of the resistor to the digital pin.
4 pin, LEDphototransistor optoisolator tester R2, 1k ohm watt carbon film resistor. Q1, 2N3904 NPN bipolar junction transistor. LED1, 5mm red LED.
Using a Photocell. by lady ada one end to Power and the other to a pulldown resistor to to the analog input of a microcontroller such as an Arduino.