One column's inputs not being registered

[pranavt]

Have a weird issue that I can't seem to figure out.

Have a 4x4 keypad, using it on an STM32 board (bluepill).

R1-R4 on keypad connected to PA4-PA7 pins. C1-C4 on keypad connected to PA3-PA0 pins.

All keys on column 1 are not registered. Tried switching wires, pins, etc. Code is the example provided with the library. No changes whatsoever.

To test a hunch, I tried the following:

#include <Arduino.h>
#include <Adafruit_Keypad.h>

const byte ROWS = 4; // rows
const byte COLS = 5; // columns
char keys[ROWS][COLS] = {
  {'Z','1','2','3','A'},
  {'Z','4','5','6','B'},
  {'Z','7','8','9','C'},
  {'Z','*','0','#','D'}
};
byte rowPins[ROWS] = {PA4, PA5, PA6, PA7}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {PA8, PA3, PA2, PA1, PA0}; //connect to the column pinouts of the keypad

//initialize an instance of class NewKeypad
Adafruit_Keypad customKeypad = Adafruit_Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS);

void setup() {
  // put your setup code here, to run once:
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, LOW);
  Serial.begin(9600);
  customKeypad.begin();
}

void loop() {
  // put your main code here, to run repeatedly:
  customKeypad.tick();

  while(customKeypad.available()){
    keypadEvent e = customKeypad.read();
    Serial.print((char)e.bit.KEY);
    if(e.bit.EVENT == KEY_JUST_PRESSED) Serial.println(" pressed");
    else if(e.bit.EVENT == KEY_JUST_RELEASED) Serial.println(" released");
  }

  delay(10);
  
}

As you can see, all I've done is add an extra column on the left in the keymap and created the keypad object with 4 rows and 5 columns. PA8 is not connected to anything. This works perfectly well. Why is the input from the first column not registered at all?

Any explanation for this behavior will be appreciated.

[dtman101]

This has always worked for me on the Mega and UNO

Code prior to setup() is as follows:

`char keys[ROWS][COLS] = { // Assign keys {'1', '2', '3', 'B', 'U'}, {'4', '5', '6', 'X', 'D'}, {'7', '8', '9', 'Y', 'V'}, {'C', '0', 'E', 'P', 'S'} }; byte rowPins[ROWS] = {7, 9, 10, 6}; //connect to the row pinouts of the keypad {R1, R2, R3, R4} byte colPins[COLS] = {12, 11, 8, 5, 4}; //connect to the column pinouts of the keypad {C1, C2, C3, C4, C5}

Adafruit_Keypad customKeypad = Adafruit_Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS ); //Create keypad instance