Light-Dependent Resistors

From Sketching with Hardware at LMU Wiki
Jump to navigation Jump to search

Description[edit]

An LDR is a light-dependent resistor. It changes it's resistance depending on the light falling onto the LDR.

Ldr01.PNG

How to connect it electrically[edit]

Connecting the light dependent resistor (LDR). The value you read is dependent on how bright it is.

Rldr.JPG


How to control it in MicroPython[edit]

This makes Pin 34 an analog input and set it to 12 bit. It reads the analog value every second and print it to the console.

 1 #Example usage for ESP32
 2 from machine import Pin, ADC
 3 from time import sleep
 4 
 5 analogPin = ADC(Pin(34))
 6 analogPin.atten(ADC.ATTN_11DB)
 7 
 8 while True:
 9   analogVal = analogPin.read()
10   print(analogVal)
11   sleep(1)


Code Example Arduino Nano Connect RP2040[edit]

A0 is the analog input with 16 bit resolution. It reads the analog value every second and print it to the console-

 1 #Example usage for Arduino Nano
 2 from machine import Pin, ADC
 3 from time import sleep
 4 
 5 analogPin = ADC(Pin(26))
 6 
 7 while True:
 8   analogVal16 = analogPin.read_u16()
 9   print(analogVal16)
10   sleep(1)

Related Tutorial Videos[edit]