DEV-12640 Pro micro is sending keyboard signals without input.

Development Boards Arduino
1

I building an led macro pad using a promicro. I uploaded the code i am using and it started to press all of the buttons even though i don’t have them connected. I tried uploading the code then holding the promicro in the air as the air

Im using the basic Arduino button circuit.

https://www.arduino.cc/en/uploads/Tutorial/button.png

If you have any questions feel free to ask.

The code:

#include <Keyboard.h>
#include <Adafruit_NeoPixel.h>
#define PIN        9
#define NUMPIXELS  16
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);
int delayval = 25;
int delA = 150;

//switches
int but8 = 0;
const int but8pin = 10;

const char *mess8 = "BEANS";

int but7 = 0;
const int but7pin = 16;
const char *mess7 = "Did you ever hear the Tragedy of Darth Plagueis the wise? I thought not. It's not a story the Jedi would tell you. It's a Sith legend. Darth Plagueis was a Dark Lord of the Sith, so powerful and so wise he could use the Force to influence the midichlorians to create life...";


int but6 = 0;
const int but6pin = 14;

int but5 = 0;
const int but5pin = 15;
const char *mess5 = "Why are we still here? Just to suffer? Every night, I can feel my leg... and my arm... even my fingers. The body I've lost... the comrades I've lost... won't stop hurting... It's like they're all still there. You feel it, too, don't you? I'm gonna make them give back our past.";

int but4 = 0;
const int but4pin = A0;

int but3 = 0;
const int but3pin = A1;

int but2 = 0;
const int but2pin = A2;

int but1 = 0;
const int but1pin = A3;

//Colors
uint32_t on = pixels.Color(255, 0, 255);

uint32_t base0  = pixels.Color(78,  202, 230);
uint32_t base1  = pixels.Color(171, 243, 114);
uint32_t base2  = pixels.Color(255, 241,  42);
uint32_t base3  = pixels.Color(255, 154, 116);
uint32_t base4  = pixels.Color(176, 150, 255);
uint32_t base5  = pixels.Color(80,  204, 225);
uint32_t base6  = pixels.Color(173, 244, 111);
uint32_t base7  = pixels.Color(252, 245,  42);
uint32_t base8  = pixels.Color(255, 186,  84);
uint32_t base9  = pixels.Color(255, 147, 123);
uint32_t base10 = pixels.Color(255, 119, 152);
uint32_t base11 = pixels.Color(255, 74,  198);
uint32_t base12 = pixels.Color(65,  167, 255);
uint32_t base13 = pixels.Color(84,  141, 255);
uint32_t base14 = pixels.Color(123, 103, 255);
uint32_t base15 = pixels.Color(140, 88,  255);


void setup() {
  // put your setup code here, to run once:

  pinMode(but8pin, INPUT);
  pinMode(but7pin, INPUT);
  pinMode(but6pin, INPUT);
  pinMode(but4pin, INPUT);
  pinMode(but3pin, INPUT);
  pinMode(but2pin, INPUT);
  pinMode(but1pin, INPUT);

  Keyboard.begin(); //Init keyboard emulation
  
  pixels.begin();
  pixels.setBrightness(75);
  
  pixels.setPixelColor(0,base0);
  pixels.setPixelColor(1,base1);
  pixels.setPixelColor(2,base2);
  pixels.setPixelColor(3,base3);
  pixels.setPixelColor(4,base4);
  pixels.setPixelColor(5,base5);
  pixels.setPixelColor(6,base6);
  pixels.setPixelColor(7,base7);
  pixels.setPixelColor(8,base8);
  pixels.setPixelColor(9,base9);
  pixels.setPixelColor(10,base10);
  pixels.setPixelColor(11,base11);
  pixels.setPixelColor(12,base12);
  pixels.setPixelColor(13,base13);
  pixels.setPixelColor(14,base14);
  pixels.setPixelColor(15,base15);
  pixels.show();

}

void loop() {
  // put your main code here, to run repeatedly:
  but8 = digitalRead(but8pin);
  but7 = digitalRead(but7pin);
  but6 = digitalRead(but6pin);
  but5 = digitalRead(but5pin);
  but4 = digitalRead(but4pin);
  but3 = digitalRead(but3pin);
  but2 = digitalRead(but2pin);
  but1 = digitalRead(but1pin);

  
  if(but8 == HIGH){
    pixels.setPixelColor(4,on);
    pixels.show();
    Keyboard.write(' ');
    for (int mess8idx = 0; mess8idx < strlen(mess8); mess8idx++){
      Keyboard.write(mess8[mess8idx]);
      }
    Keyboard.releaseAll();
    Keyboard.write(' ');
    delay(delayval);
    pixels.setPixelColor(4,base4);
    pixels.show();
  }
  
  if(but7 == HIGH){
    pixels.setPixelColor(5,on);
    pixels.show();
    Keyboard.write(' ');
      for (int mess7idx = 0; mess7idx < strlen(mess7); mess7idx++){
      Keyboard.write(mess7[mess7idx]);
      }
    Keyboard.write(' ');
    delay(delayval);
    pixels.setPixelColor(5,base5);
    pixels.show();
  }

  if(but6 == HIGH){
    pixels.setPixelColor(6,on);
    pixels.show();
    Keyboard.write(' ');
    delay(delayval);
    pixels.setPixelColor(6,base6);
    pixels.show();
  }

  if(but5 == HIGH){
    pixels.setPixelColor(7,on);
    pixels.show();
    Keyboard.write(' ');
    for(int mess5idx = 0; mess5idx < strlen(mess5); mess5idx++){
      Keyboard.write(mess5[mess5idx]);
    }
    Keyboard.write(' ');
    delay(delayval);
    pixels.setPixelColor(7,base7);
    pixels.show();
    
  }
  
  if(but4 == HIGH){
    pixels.setPixelColor(0,on);
    pixels.show();
    Keyboard.press(KEY_LEFT_CTRL);
    Keyboard.press(KEY_LEFT_ALT);
    Keyboard.press(KEY_DELETE);
    delay(delayval + delA);
    Keyboard.releaseAll();
    pixels.setPixelColor(0,base0);
    pixels.show();
  }
  
  if(but3 == HIGH){
    pixels.setPixelColor(1,on);
    pixels.show();
    Keyboard.press(KEY_F15);
    delay(delayval + delA);
    Keyboard.releaseAll();
    pixels.setPixelColor(1,base1);
    pixels.show();
  }
  
  if(but2 == HIGH){
    pixels.setPixelColor(2,on);
    pixels.show();
    Keyboard.press(KEY_F14);
    delay(delayval + delA);
    Keyboard.releaseAll();
    pixels.setPixelColor(2,base2);
    pixels.show();
  }

if(but1 == HIGH){
    pixels.setPixelColor(3,on);
    pixels.show();
    Keyboard.press(KEY_F13);
    delay(delayval + delA);
    Keyboard.releaseAll();
    pixels.setPixelColor(3,base3);
    pixels.show();
  }  
  
  
/*  for(int i=1;i<100;i++){
  pixels.setPixelColor(0,pixels.Color(i,0,0)); 
  pixels.show();
  delay(100);
  } */
}
2

Hi, thanks for writing in.

There could be a chance that the pins designated as keyboard pins are simply floating and might need a pull down resistor along with the button attached to each pin in order to be used properly.

Does the example code have a hardware diagram that shows how the hardware is connected? If so, maybe try adding the other hardware and see if that helps.

3

I made sure i used a pull down shem; https://ibb.co/D9QPsyw

4

Do you have a multimeter handy? If so, measure the voltage between the wire connecting a button to the Arduino’s input and ground. It should measure 5V when the button is pressed, and 0 volts when it is not pressed. If you don’t see that, you have a connection problem. If you don’t have a multimeter, you could use an LED and a series resistor in the 200-500 ohm range.

/mike

5

I tested it out an I got a tiny bit less then 5v when pressed and 0 when not pressed.

6

That sounds right. In the beginning, you mention that “you don’t have the buttons connected”. For the ones you don’t have connected, do you at least have the pulldown resistors? If not (ie. there is nothing connected to the pin), you will pick up noise and trigger the input (especially without debouncing). In that case, ground those inputs or comment around the tests in the code.

You can also print the state of but1 thru but8 to see what the Arduino is actually reading.

/mike

7

By not connected I mean I had not soldered anything to it. I do have pull up resistors on the pcb.