jesboard.ino

#include <Keyboard.h>

#define NKEYS 3

unsigned long mintime = 20; // ms (debounce time)

int keypin[NKEYS] = {2,3,4};
char letter[NKEYS] = {'j', 'e', 's'};
int isdown[NKEYS];
unsigned long lastchange[NKEYS];

void setup() {
  Keyboard.begin();

  for (int i = 0; i < NKEYS; i++)
    pinMode(keypin[i], INPUT_PULLUP);
}

void loop() {
  for (int i = 0; i < NKEYS; i++) {
    int down = !digitalRead(keypin[i]);
    if (down != isdown[i]) {
      isdown[i] = down;
      lastchange[i] = millis();
    }
    if (millis() - lastchange[i] > mintime) {
      if (isdown[i]) {
        Keyboard.press(letter[i]);
      } else {
        Keyboard.release(letter[i]);
      }
    }
  }
}