静電タッチキーボード TTP229用のコード

sketch.ino

/**
 * Original code: http://forum.hobbycomponents.com/viewtopic.php?f=73&t=1781
 *
 *
 * This is an example of how to use the Hobby Components 16 key capacitive touch
 * keypad (HCMODU0079). This example sketch will read the current state of the
 * of the keypad and if a key is pressed output its key number to the serial port.
 *
 * The sketch assumes that the keypad is configured to 16 key active low mode
 * by shorting pads P1-3 and P1-P4 together (see schematic or sport forum for more
 * information). Connect the keypad to your Arduino as follows:
 *
 * Keypad......Arduino
 * VCC.........+5V
 * GND.........GND
 * SCL.........Digital pin 8
 * SDO.........Digital pin 9
 *
 * You may copy, alter and reuse this code in any way you like, but please leave
 * reference to HobbyComponents.com in your comments if you redistribute this code.
 *
 * This software may not be used directly for the purpose of promoting products that
 * directly compete with Hobby Components Ltd's own range of products.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS". HOBBY COMPONENTS MAKES NO WARRANTIES,
 * WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ACCURACY OR
 * LACK OF NEGLIGENCE. HOBBY COMPONENTS SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE
 * FOR ANY DAMAGES INCLUDING, BUT NOT LIMITED TO, SPECIAL, INCIDENTAL OR
 * CONSEQUENTIAL DAMAGES FOR ANY REASON WHATSOEVER.
 */

#include "Keyboard.h"


/* Define the digital pins used for the clock and data */
#define SCL_PIN 8
#define SDO_PIN 9

void setup()
{
  Keyboard.begin();
  /* Configure the clock and data pins */
  pinMode(SCL_PIN, OUTPUT);
  pinMode(SDO_PIN, INPUT);
}

byte prev = 0;

/* Main program */
void loop()
{
  /* Read the current state of the keypad */
  byte now = Read_Keypad();

  /* If a key has been pressed output it to the serial port */
  if ((now != prev) && now) {
    Keyboard.write('a' + now);
  }

  prev = now;
}


/* Read the state of the keypad */
byte Read_Keypad(void)
{
  byte Count;
  byte Key_State = 0;

  /* Pulse the clock pin 16 times (one for each key of the keypad)
     and read the state of the data pin on each pulse */
  for(Count = 1; Count <= 16; Count++)
  {
    digitalWrite(SCL_PIN, LOW);

    /* If the data pin is low (active low mode) then store the
       current key number */
    if (!digitalRead(SDO_PIN))
      Key_State = Count;

    digitalWrite(SCL_PIN, HIGH);
  }

  return Key_State;
}