NodeMCU ESP8266 pin always low

[mrnams]

Once we give low input to pin 16 of NodeMCU ESP8266, it remains low, see my code below which is not able to switch off led because of this issue, can't we use pin 16 as general purpose input?
See my complete code

#include <Arduino.h>
#define ENABLE_DEBUG

#ifdef ENABLE_DEBUG
#define DEBUG_ESP_PORT Serial
#define NODEBUG_WEBSOCKETS
#define NDEBUG
#endif

enum LedStatus
{
  LedOff = 0,
  LedOn = 1
};
enum LedStatus curentLedStatus = LedOff;
#define BAUD_RATE 9600
// Pins of push buttons and led
#define pinPButtonLedOn 16
#define pinPButtonLedOff 5
#define pinLed 4

void setup()
{
  Serial.begin(BAUD_RATE);
  // put your setup code here, to run once:
  pinMode(pinPButtonLedOn, INPUT_PULLUP);  // set arduino pin to input pull-up mode
  pinMode(pinPButtonLedOff, INPUT_PULLUP); // set arduino pin to input pull-up mode
  pinMode(pinLed, OUTPUT);                 // set arduino pin to output mode
}

void loop()
{
  // put your main code here, to run repeatedly:
  Serial.printf("\n \n \n  On button state :");
  Serial.print(digitalRead(pinPButtonLedOn));

  Serial.printf("\n \n \n Off button state :");
  Serial.print(digitalRead(pinPButtonLedOff));

  if (digitalRead(pinPButtonLedOn) == LOW && curentLedStatus == LedOff)
  {
    digitalWrite(pinLed, HIGH);
    curentLedStatus = LedOn;
    Serial.printf("\n \n \n Led turned On by Push Button");
  }

  if (digitalRead(pinPButtonLedOff) == LOW && curentLedStatus == LedOn)
  {
    digitalWrite(pinLed, LOW);
    curentLedStatus = LedOff;
    Serial.printf("\n \n \n Led turned Off by Push Button");
  }
}

[moderator action: removed link to external file server]

 

[KlausST]

Hi,

try:

  if ( (digitalRead(pinPButtonLedOn) == LOW) && (curentLedStatus == LedOff) )

change the other "IF..." line the same way.

Klaus

***
added:
also check if this is correct:

enum LedStatus curentLedStatus = LedOff;

maybe change it to:

int LedStatus curentLedStatus = LedOff;

 

[mrnams]

Hi,

try:

  if ( (digitalRead(pinPButtonLedOn) == LOW) && (curentLedStatus == LedOff) )

change the other "IF..." line the same way.

Klaus

***
added:
also check if this is correct:

enum LedStatus curentLedStatus = LedOff;

maybe change it to:

int LedStatus curentLedStatus = LedOff;

Its not problem of logic, i have printed state of pin and for pin 16 it always print 0 i.e. low

// put your main code here, to run repeatedly:
  Serial.printf("\n \n \n  On button state :");
  Serial.print(digitalRead(pinPButtonLedOn));

  Serial.printf("\n \n \n Off button state :");
  Serial.print(digitalRead(pinPButtonLedOff));

 

[KlausST]

Hi,

printing the current states gives no usful debug information.

Klaus

 

[mrnams]

Yes, but actually it low, thats why led is not turning off

 

[danadakk]

You have the right pin mapping in mind from physical ESP8266 pin to Arduino pin ?

ESP8266 NodeMCU pinout for Arduino IDE

A cheat sheet to remember the pinout of the ESP8266 NodeMCU V2 and V3 boards for your Arduino IDE programs.

mechatronicsblog.com

Regards, Dana

 

[KlausST]

Hi,

I don´t see your schematic.... so I can´t validate sates.

Klaus

 

[mrnams]

 

[KlausST]

Hi,

LED without current limiting resistor???
Did you check that all connections are valid?

Do you have a voltmeter?

Klaus

 

[mrnams]

yes all connections are valid, led can bear upto 5v

 

[betwixt]

LEDs are current driven, not voltage driven, even at 3.3V from the NodeMCU it will overload the output pin. Use a resistor.

I can't see in your code where it makes the LED pin high.

Brian.

 

[andre_luis]

You are seemingly assuming that can use GPIO indexes to refer to I/O's, which is not allways true in the Arduino world.
There is an intrinsic mapping, so instead of using this...

#define pinPButtonLedOn 16
#define pinPButtonLedOff 5
#define pinLed 4

You should consider using that

#define pinPButtonLedOn D0
#define pinPButtonLedOff D1
#define pinLed D2

 

[betwixt]

Personally, I've stopped referring to the different types of board and use the 'generic' description instead. Partly that's because after using something like a NodeMCU for development, the final product only uses the actual ESP module without the rest of the board.

Aside from the pin number/name issue and the LED and enumerating strangeness, I can't see why there is any need to record the present LED state when it never changes unless a button is pressed. Simply 'if on is pressed turn it on' and 'if off is pressed turn it off' should work equally well. Saving the state is only necessary if it is being toggled with a single switch and the previously recorded condition has to be changed.

Brian.

 

[mrnams]

You are seemingly assuming that can use GPIO indexes to refer to I/O's, which is not allways true in the Arduino world.
There is an intrinsic mapping, so instead of using this...

#define pinPButtonLedOn 16
#define pinPButtonLedOff 5
#define pinLed 4

You should consider using that

#define pinPButtonLedOn D0
#define pinPButtonLedOff D1
#define pinLed D2

No, that does not make any difference

 

[mrnams]

Personally, I've stopped referring to the different types of board and use the 'generic' description instead. Partly that's because after using something like a NodeMCU for development, the final product only uses the actual ESP module without the rest of the board.

Aside from the pin number/name issue and the LED and enumerating strangeness, I can't see why there is any need to record the present LED state when it never changes unless a button is pressed. Simply 'if on is pressed turn it on' and 'if off is pressed turn it off' should work equally well. Saving the state is only necessary if it is being toggled with a single switch and the previously recorded condition has to be changed.

Brian.

You are right, thanks a lot. I am new here, this is my first project of NodeMCU