Reading Temperature and Humidity DHT22 sensors from 16 channel Multiplexer

Hi everyone!
I've been searching all over how to read the temperature and humidity of the DHT22 sensors when connected to one of the 16 channel of multiplexer 74HC4067 (

I've seen this post: Mux Shield and DHT22 Temperature Sensor - UNO Rv3
However it's not the same multiplexer that I used and it's quite difficult for me to follow through the discussion.

Below is the example sketch of DHT22 sensor library that I use. It's from Rob Tillaart.

// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain

// REQUIRES the following Arduino libraries:
// - DHT Sensor Library:
// - Adafruit Unified Sensor Lib:

#include "DHT.h"

#define DHTPIN 2     // Digital pin connected to the DHT sensor
// Feather HUZZAH ESP8266 note: use pins 3, 4, 5, 12, 13 or 14 --
// Pin 15 can work but DHT must be disconnected during program upload.

// Uncomment whatever type you're using!
//#define DHTTYPE DHT11   // DHT 11
#define DHTTYPE DHT22   // DHT 22  (AM2302), AM2321
//#define DHTTYPE DHT21   // DHT 21 (AM2301)

// Connect pin 1 (on the left) of the sensor to +5V
// NOTE: If using a board with 3.3V logic like an Arduino Due connect pin 1
// to 3.3V instead of 5V!
// Connect pin 2 of the sensor to whatever your DHTPIN is
// Connect pin 3 (on the right) of the sensor to GROUND (if your sensor has 3 pins)
// Connect pin 4 (on the right) of the sensor to GROUND and leave the pin 3 EMPTY (if your sensor has 4 pins)
// Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor

// Initialize DHT sensor.
// Note that older versions of this library took an optional third parameter to
// tweak the timings for faster processors.  This parameter is no longer needed
// as the current DHT reading algorithm adjusts itself to work on faster procs.

void setup() {
  Serial.println(F("DHTxx test!"));


void loop() {
  // Wait a few seconds between measurements.

  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  float h = dht.readHumidity();
  // Read temperature as Celsius (the default)
  float t = dht.readTemperature();
  // Read temperature as Fahrenheit (isFahrenheit = true)
  float f = dht.readTemperature(true);

  // Check if any reads failed and exit early (to try again).
  if (isnan(h) || isnan(t) || isnan(f)) {
    Serial.println(F("Failed to read from DHT sensor!"));

  // Compute heat index in Fahrenheit (the default)
  float hif = dht.computeHeatIndex(f, h);
  // Compute heat index in Celsius (isFahreheit = false)
  float hic = dht.computeHeatIndex(t, h, false);

  Serial.print(F("Humidity: "));
  Serial.print(F("%  Temperature: "));
  Serial.print(F("°C "));
  Serial.print(F("°F  Heat index: "));
  Serial.print(F("°C "));

And here is the multiplexer library that I use: Stefano Chizzolini

 * This example demonstrates how to read digital signals.
 * It assumes there are push buttons with pullup resistors connected to the 16
 * channels of the 74HC4067 mux.
 * ------------------------------------------------------------
 * Project: arduino-ad-mux-lib
 * Source:
 * Author: Nick Lamprianidis (adaptation by Stefano Chizzolini)

#include <Arduino.h>
#include "Mux.h"

using namespace admux;

 * Creates a Mux instance.
 * 1st argument is the SIG (signal) pin (Arduino digital input pin 3).
 * 2nd argument is the S0-S3 (channel control) pins (Arduino pins 8, 9, 10, 11).
Mux mux(Pin(3, INPUT, PinType::Digital), Pinset(8, 9, 10, 11));

void setup() {
  // Serial port initialization.
  Serial.begin(9600); while (!Serial) /* Waits for serial port to connect (needed for Leonardo only) */;

 * Reads the 16 channels and reports on the serial monitor if the corresponding
 * push button is pressed.
void loop() {
  byte data;
  for (byte i = 0; i < mux.channelCount(); i++) {
    data = /* Reads from channel i (returns HIGH or LOW) */;

    Serial.print("Push button at channel "); Serial.print(i); Serial.print(" is "); Serial.println(data == LOW ? "pressed" : "not pressed");


Anyone can help me with this?

It appears you do not fully understand the hardware and software. Why not get the same mux used in your code and get it working first before changing.

I got the mux working using the code already. The code is working.

What I don't fully understand i how to implement this code:


when using mux since the dht22 sensor is connected to the mux in a single pin.
It seems that I have to adjust the code for the Mux file but I have never done that so if there's any pointers on how to do it or tips it will be very helpful.

I've also looked some tutorials on youtube on using Mux, and several of them does not use mux library, I havent use this method before but I'm also working on this too.

I would not know why you need a library to operate a Mux. Select the channel and then read or write. This process varies a bit with different mux devices and hardware connections but the basic principle is the same. Here are two links that will explain it to you. What is Multiplexer, How it works & Multiplexer Circuit

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