USBKeyboard.h occasionally hangs

Projects Programming
40

Hi Nick,

Thanks for your help. Please find my header definitions and setup() function code below:

EDIT: Didn't post the latest version of the code -- posted version did not have Serial.begin(9600); at the bottom of setup().

#include "UsbKeyboard.h"

// Define the inputs to use for buttons
#define BUTTON_A 6
#define BUTTON_B 7
#define BUTTON_C 8
#define BUTTON_D 9
#define BUTTON_MSG 10
#define BUTTON_ENTER 11

// Use the on-board LED as an activity display
int ledPin = 13;

/**
 * Configure button inputs and set up the USB connection to the host
 */
void setup()
{
  // Set up the activity display LED
  pinMode (ledPin, OUTPUT);
  digitalWrite (ledPin, HIGH);

  // Set the button pins to inputs
  pinMode (BUTTON_A, INPUT);
  pinMode (BUTTON_B, INPUT);
  pinMode (BUTTON_C, INPUT);
  pinMode (BUTTON_D, INPUT);
  pinMode (BUTTON_MSG, INPUT);
  pinMode (BUTTON_ENTER, INPUT);

  // Enable the CPU's internal 20k pull-up resistors on the button
  // inputs so they default to a "high" state
  digitalWrite (BUTTON_A, HIGH);
  digitalWrite (BUTTON_B, HIGH);
  digitalWrite (BUTTON_C, HIGH);
  digitalWrite (BUTTON_D, HIGH);
  digitalWrite (BUTTON_MSG, HIGH);
  digitalWrite (BUTTON_ENTER, HIGH); 

  // Disable timer0 since it can mess with the USB timing. Note that
  // this means some functions such as delay() will no longer work.
  TIMSK0&=!(1<<TOIE0);

  // Clear interrupts while performing time-critical operations
  cli();

  // Force re-enumeration so the host will detect us
  usbDeviceDisconnect();
  delayMs(250);
  usbDeviceConnect();

  // Set interrupts again
  sei();

//Begin serial
Serial.begin(9600);
}

In my test setup, I'm trying to read pin 8, which is BUTTON_C.