Patrick Posts - Answer Overflow

Patrick

•Created by Patrick on 5/11/2025 in #coding-help

Keyboard using keypad and keyboard libraries together

I am trying to make a keyboard script for an stm32 based development board using the keypad and keyboard libraries. I used a default script from the keypad library then added a keyboard function from the keyboard library to send keystrokes to the connected computer. My problem is that the script below does not send any keystrokes. I am able to send a key when I have a keyboard.write function alone, but not when it is inside that if statement. I can also send the pressed letter through serial (using an UNO, not the stm32 board as It doesn't connect to the serial monitor) so I know that the keypad script works alone.

#include <Keyboard.h>
#include <Keypad.h>

const byte ROWS = 4; 
const byte COLS = 3; 

char hexaKeys[ROWS][COLS] = {
  {'A', 'B', 'C'},
  {'D', 'E', 'F'},
  {'G', 'H', 'I'},
  {'J', 'K', 'L'}
};

byte rowPins[ROWS] = {PA2, PA3, PA6, PB1}; 
byte colPins[COLS] = {PB11, PB14, A9};

Keypad customKeypad = Keypad(makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS); 

void setup(){
  Serial.begin(9600);
  Keyboard.begin();
}
  
void loop(){
  char customKey = customKeypad.getKey();

  if (customKey){
    //Serial.println(customKey);
    Keyboard.write(customKey);
  }
}

#include <Keyboard.h>
#include <Keypad.h>

const byte ROWS = 4; 
const byte COLS = 3; 

char hexaKeys[ROWS][COLS] = {
  {'A', 'B', 'C'},
  {'D', 'E', 'F'},
  {'G', 'H', 'I'},
  {'J', 'K', 'L'}
};

byte rowPins[ROWS] = {PA2, PA3, PA6, PB1}; 
byte colPins[COLS] = {PB11, PB14, A9};

Keypad customKeypad = Keypad(makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS); 

void setup(){
  Serial.begin(9600);
  Keyboard.begin();
}
  
void loop(){
  char customKey = customKeypad.getKey();

  if (customKey){
    //Serial.println(customKey);
    Keyboard.write(customKey);
  }
}

1 replies

AArduino

•Created by Patrick on 4/6/2025 in #hardware-help

Bidirectional I/O buffer

For something I am making I am going to have each I/O pin of a microcontroller controlling the gate of a transistor or MOSFET. But I also want to use those I/O pins as inputs while only connecting devices to the drain or source of each transistor. Is there a type of transistor that would allow current to flow back through the body to the gate? Or would I need some extra components to do that reliably.

167 replies

AArduino

•Created by Patrick on 11/12/2024 in #hardware-help

Custom motor driver module

I am planning to make a high current motor driver module with IRLZ34NPBF mosfets. But I am wondering what components to add to make a nicely working system, like resistors, capacitors, and diodes. I know I need a 10k resistor for the gate to ground, and I know I need diodes from the drain to the vcc. But is there anything else I should have other than those?

722 replies

Gaming

Programming