MPR121 (capacitive button) and ESP8266 (ESP12F)

Projects Networking, Protocols, and Devices
1

Hello

I'm having problem MPR121 capacitive button module. When I reset the board, I'm receiving an error like the copied text below. The module work OK after the initial upload.

I measured 6.5 K pullup resistance on both SDA / SDL when the MPR121 module is installed. The module is using the 0x5A adress.

Any idea on how to resolved that?

Martin

⸮Adafruit MPR121 Capacitive Touch sensor test
MPR121 not found, check wiring?

--------------- CUT HERE FOR EXCEPTION DECODER ---------------

Soft WDT reset

Exception (4):
epc1=0x40201088 epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000000 depc=0x00000000

stack>>>

ctx: cont
sp: 3ffffe50 end: 3fffffd0 offset: 0160
3fffffb0: feefeffe feefeffe 3ffee70c 40202cac
3fffffc0: feefeffe feefeffe 3fffdab0 40100f21
<<<stack<<<

Code I used

/*
  3X4-MPR121-Capacitive-Touch-Keypad-Module
  Modified on 10 Jan 2021
  by Amir Mohammad Shojaee @ Electropeak
  Home
  
  based on Adafruit Library Example 
*/

#include <Wire.h>
#include "Adafruit_MPR121.h"

#ifndef _BV
#define _BV(bit) (1 << (bit)) 
#endif

// You can have up to 4 on one i2c bus but one is enough for testing!
Adafruit_MPR121 cap = Adafruit_MPR121();

// Keeps track of the last pins touched
// so we know when buttons are 'released'
uint16_t lasttouched = 0;
uint16_t currtouched = 0;

void setup() {
  Serial.begin(9600);


  while (!Serial) { // needed to keep leonardo/micro from starting too fast!
    delay(10);
  }
  
  Serial.println("Adafruit MPR121 Capacitive Touch sensor test"); 
  
  // Default address is 0x5A, if tied to 3.3V its 0x5B
  // If tied to SDA its 0x5C and if SCL then 0x5D
  if (!cap.begin(0x5A)) {
    Serial.println("MPR121 not found, check wiring?");
    while (1);
  }
  Serial.println("MPR121 found!");
}
2

what does it mean ?

3 
#include <Wire.h>
#include "Adafruit_MPR121.h"
Adafruit_MPR121 cap = Adafruit_MPR121();

void setup() {
  Serial.begin(115200);

  
  // Default address is 0x5A, if tied to 3.3V its 0x5B
  // If tied to SDA its 0x5C and if SCL then 0x5D
  if (!cap.begin(0x5A)) {
    Serial.println("MPR121 not found, check wiring?");
    return;
  }
  Serial.println("MPR121 found!");
}
void loop(){}