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DeMux for Arduiono 74HC4067 with Wemos Mini, probel with setting digital pins

#1

Hello,
I have a problem with my project and I require some help please. Im using a wemos D1 mini and I want to measure multiple analog signals. For that I’m using 74HC4067 16 channel mux.
To activate a specific channel I have to set some digitial Pins to high or low.

I would like to set digital Pins in “void sensorData()”, save the value and send it to a virtual pin to blynk. Then activate another channel and save it to anoter virtual pin. But it does not work. I only get values on my Analog pin, if I set the values for the digital pins in void loop(). If I try to set the digital pins inside “void SensorData()” it’s not working
Here is a part of my code which does not work?

void sendSensor()
{
  digitalWrite(MUXPinS3, LOW);
  digitalWrite(MUXPinS2, LOW);
  digitalWrite(MUXPinS1, LOW);
  digitalWrite(MUXPinS0, LOW);
  int sensorData = analogRead(A0); //reading the sensor on A0
  sensorData = map (sensorData,0, 1023, 100, 0);
  Blynk.virtualWrite(V8, sensorData); //sending to Blynk
  Serial.println("Sensor 1: ");
  Serial.println(sensorData);
  }

void loop(){  Blynk.run();       }

Thank you for your help

#2

I don’t think that I can help you, but others might if you post your complete sketch!

#3

Here the code

/**************************************************************
Measuring Moisture for Plants

Sending E-Mail
}
 **************************************************************/
#define BLYNK_PRINT Serial    // Comment this out to disable prints and save space
#include <SPI.h>
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
//#include <SimpleTimer.h>
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = ""; //Enter the Auth code which was send by Blink

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "";  //Enter your WIFI Name aterm-9fdb33-g
char pass[] = "";  //Enter your WIFI Password 5b62bf4ca241


//Mux control pins
int MUXPinS0 = D0;
int MUXPinS1 = D1;
int MUXPinS2 = D2;
int MUXPinS3 = D3;



BlynkTimer timer;

//unsigned long EmailTimer=0;


void sendSensor()
{
  digitalWrite(MUXPinS0,LOW)
  digitalWrite(MUXPinS1,LOW)
  digitalWrite(MUXPins2,LOW)
  digitalWrite(MUXPinS3,LOW)
  int sensorData = analogRead(A0); //reading the sensor on A0
  sensorData = map (sensorData,0, 1023, 100, 0);
  Blynk.virtualWrite(V8, sensorData); //sending to Blynk
  Serial.println("Sensor 1: ");
  Serial.println(sensorData);
  digitalWrite(MUXPinS0,HIGH)
  digitalWrite(MUXPinS1,HIGH)
  digitalWrite(MUXPins2,LOW)
  digitalWrite(MUXPinS3,LOW)
  int sensorData1 = analogRead(A0); //reading the sensor on A0
  sensorData = map (sensorData1,0, 1023, 100, 0);
  Blynk.virtualWrite(V9, sensorData1); //sending to Blynk
  Serial.println("Sensor 2: ");
  Serial.println(sensorData)
  }

void setup()
{
  pinMode(MUXPinS0, OUTPUT); 
  pinMode(MUXPinS1, OUTPUT); 
  pinMode(MUXPinS2, OUTPUT); 
  pinMode(MUXPinS3, OUTPUT); 

  Serial.begin(9600); // See the connection status in Serial Monitor
  Blynk.begin(auth, ssid, pass);
 
  timer.setInterval(6000L, sendSensor); // Setup a function to be called every 6 second

}

void loop()
{
  Blynk.run(); // Initiates Blynk
  timer.run(); // Initiates SimpleTimer
}
#4

What are you seeing in your serial monitor when you run this code?

You’re mixing-up your sensorData and sensorData1 variables in the second part of your function…

but that shouldn’t stop you getting some readings at least.

Pete.

#5

You are right. There is small error. But that is not important. I get some reading but without any sense. The values are far from what they should be. If I copy this part:

  digitalWrite(MUXPinS0,LOW)
  digitalWrite(MUXPinS1,LOW)
  digitalWrite(MUXPins2,LOW)
  digitalWrite(MUXPinS3,LOW)

to “void loop”, I get correct readings.

#6

Why don’t you want to share your serial monitor output?

Pete.

#7

Random number it seems:

   ___  __          __
   / _ )/ /_ _____  / /__
  / _  / / // / _ \/  '_/
 /____/_/\_, /_//_/_/\_\
        /___/ v0.6.1 on ESP8266

[4488] Connecting to blynk-cloud.com:80
[5077] Ready (ping: 20ms).
Sensor 1: 
100
Sensor 2: 
7
Sensor 1: 
100
Sensor 2: 
8
Sensor 1: 
100
Sensor 2: 
7
#8

Is this with the code exactly as you posted it, or did you fix the sensorData/sensorData1 issue first?

Pete.

#9

Hey Pete,
it was after fixing the code.
I worked on the code and I thing I solved the problem. I’m not sure what the problem was, but it’s solved. I’m setting the digital pins and reading the analog pin in a subfunction now. Down below is the code.
Now I have another question. Im saving the analog signal in an array[i]. This data I would like to save to virtual pin V1 to V[i]. Right now I’m doing it with a “if” statement. Is it possible to do it with a loop?
Thank you very much.

/**************************************************************
Measuring Moisture for Plants

Sending E-Mail
}
 **************************************************************/
#define BLYNK_PRINT Serial    // Comment this out to disable prints and save space
#include <SPI.h>
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
//#include <SimpleTimer.h>
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = ""; //Enter the Auth code which was send by Blink

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "";  //Enter your WIFI Name aterm-9fdb33-g
char pass[] = "";  //Enter your WIFI Password 5b62bf4ca241


//Mux control pins
int MUXPinS0 = D4;
int MUXPinS1 = D1;
int MUXPinS2 = D2;
int MUXPinS3 = D3;

int myArray[16];
int pin; 

BlynkTimer timer;

//unsigned long EmailTimer=0;


void sendSensor()
{
        for (int i = 0; i < 2; i++)
    {
      myArray[i]= getAnalog(i);
      myArray[i] = map (myArray[i],0, 1023, 100, 0);
      if (i==0)
      {pin = V0;
      }
      if (i==1)
      {pin =V1;
      }
      Blynk.virtualWrite(pin, myArray[i]); //sending to Blynk
      Serial.print("Sensor 1: ");
      Serial.print(myArray[0]);
      Serial.print(", ");
      Serial.print("Sensor 2: ");
      Serial.println(myArray[1]);

    }


  }

void setup()
{
  pinMode(MUXPinS0, OUTPUT); 
  pinMode(MUXPinS1, OUTPUT); 
  pinMode(MUXPinS2, OUTPUT); 
  pinMode(MUXPinS3, OUTPUT); 
  

  Serial.begin(9600); // See the connection status in Serial Monitor
  Blynk.begin(auth, ssid, pass);
 
  timer.setInterval(6000L, sendSensor); // Setup a function to be called every 6 second

}

void loop()
{
  
      Blynk.run(); // Initiates Blynk
      timer.run(); // Initiates SimpleTimer   

}
float getAnalog(int MUXyPin) {
  //MUXyPin must be 0 to 15 representing the analog pin you want to read
  //MUXPinS3 to MUXPinS0 are the Arduino pins connected to the selector pins of this board.
  digitalWrite(MUXPinS3, HIGH && (MUXyPin & B00001000));
  digitalWrite(MUXPinS2, HIGH && (MUXyPin & B00000100));
  digitalWrite(MUXPinS1, HIGH && (MUXyPin & B00000010));
  digitalWrite(MUXPinS0, HIGH && (MUXyPin & B00000001));
  return (float)analogRead(A0);
}
#10

Yes. The ‘V’ is optional in the Blynk.virtualWrite(vPin,value) command, so you can simply do Blynk.virtualWrite(i, array[i])

Pete.