MQ-135 and ESP32 analog - ohm?

Using Arduino Sensors
1

The MQ-135 is 5V and the output is analog, which will also be 5V. I have an ESP32 that has an analog at about 3.3V. I will use a divider but I don't know what resistors to use. Somewhere I saw 100K and 200K ohm, in other places only 33K and 18K ohm. how is it please Thank you very much for your help.

2

try 1K and 2K (I often use 1K and 2.2K but it gives a slightly higher voltage than 3.3V)

3

The ESP32 ADC has an input range of 150mV-3100mV
Are use using some ESP32 board/kit?
Are you using thr bare MQ-135 sensor or some board/module.

4

Hi,
I Goggled;

esp32 MQ-135

This may help.

Tom.. :grinning: :+1: :coffee: :australia:

5

I have ESP32 modul WROOM-32 and MQ-135 is module.

6

Use a 62K and 39K.

7

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