I am using an ESP32-Board (NodeMCU ESP32 from joy-it) and want to read a voltage value. I have connected an 100K potentiometer between GND and 3,3V and the pin in the middle of the pot to GPIO 13.
If I now upload this code in the Iot Cloud and open the Serial Monitor it prints "0" the value of "pot", even when i connect 3,3 V to GPIO 13.
/*Arduino IoT Cloud Variables description
The following variables are automatically generated and updated when changes are made to the Thing
int pot;
bool led;
Variables which are marked as READ/WRITE in the Cloud Thing will also have functions
which are called when their values are changed from the Dashboard.
These functions are generated with the Thing and added at the end of this sketch.
*/
#include "thingProperties.h"
int pinPot = 13;
int ledpin = 2;
void setup() {
// Initialize serial and wait for port to open:
Serial.begin(9600);
// This delay gives the chance to wait for a Serial Monitor without blocking if none is found
delay(1500);
pinMode(ledpin, OUTPUT);
// Defined in thingProperties.h
initProperties();
// Connect to Arduino IoT Cloud
ArduinoCloud.begin(ArduinoIoTPreferredConnection);
/*
The following function allows you to obtain more information
related to the state of network and IoT Cloud connection and errors
the higher number the more granular information you’ll get.
The default is 0 (only errors).
Maximum is 4
*/
setDebugMessageLevel(4);
ArduinoCloud.printDebugInfo();
}
void loop() {
ArduinoCloud.update();
// Your code here
pot = analogRead(pinPot);
Serial.println(pot);
delay(500);
}
/*
Since Led is READ_WRITE variable, onLedChange() is
executed every time a new value is received from IoT Cloud.
*/
void onLedChange() {
// Add your code here to act upon Led change
if(led) {
digitalWrite(ledpin, HIGH);
}
else {
digitalWrite(ledpin, LOW);
}
}
The onLedChange() works fine, I can turn on/off my LED through my Dashboard.
The GPIO 13 is not defect because if I upload the sketch below, with my Arduino IDE 1.8 the output is a value from 0 to 4095 (12 bit ADC) depending on how I turn the potentiometer.
int pot;
int pinPot = 13;
void setup() {
// Initialize serial and wait for port to open:
Serial.begin(9600);
// This delay gives the chance to wait for a Serial Monitor without blocking if none is found
delay(1500);
}
void loop() {
pot = analogRead(pinPot);
Serial.print("pot = ");
Serial.println(pot);
delay(500);
}
If you look at the first code in the Iot Cloud in the loop(). Now I give "pot" the value of 50 instead of analogRead(pot); and the output of the Serial Monitor is 50, I can also see that in my Dashboard.
I have also tried that with random(100) and it also works.
void loop() {
ArduinoCloud.update();
// Your code here
pot = 50;
Serial.println(pot);
delay(500);
}
I think there is a problem with analogRead() in the Iot Cloud or my code is somewhere wrong.
Can someone please explain why I am getting "0" as the output with analogRead() in the Iot Cloud?