3. Analog Input with ESP32 Using Micro-Python Programming

Today I'll show you how to read an analog value from any analog sensor using ESP32 and Micro-Python Programming. This is very useful when working with analog sensors like potentiometers, LDR, MQ sensors, etc.

Description:

There are several pins on the ESP32 that can use as analog pins- these are called ADC pins. Like - 0, 2, 4, 12, 13, 14, 15, 25, 26, 27, 32, 33, 34, 35, 36, and 39.

ESP32 ADC pins have 12-bit resolution by default. That means these pins read voltage between 0 and 3.3V and then return a value between 0 and 4095

Component use:

1. ESP32
2. LDR sensor
3. 1 KΩ resistor
4. Breadboard
5. Connecting Wire
6. Micro-USB cable for uploading Code to ESP32
7. Thonny IDE install on pc

Pin Diagram -

1. LDR any leg connect to 3.3V.
2. LDR's other leg is connected to a 1 KΩ resistor.
3. Connect the other resistor leg to the ground.
4. Connect a connecting wire to the ldr-resistor leg to the D34 pin of ESP32.

Circuit Diagram

Code:

from machine import Pin, AD
from time import sleep


pot = ADC(Pin(34))


pot.atten(ADC.ATTN_11DB) # Full range: 3.3v


while True:
    pot_value = pot.read()
    print(pot_value)
    sleep(0.1)C        

Serial Monitor

Video: