In this instructable i will show how to make a touch sensitive stopwatch like the SpeedStack's stopwatch.

Whatch it works

First test with the OLED

Step 1: Supplies:

* Arduino pro mini
* Adafruit OLED screen (128*68 i2c)
* Copper tape
* 2 Leds
* 2 10 Kohm resistors
* 3 220 ohm resistors
* Wire

****** NOTICE: The touch sensitive are actually made of copper tape and resistor using the CapSense lib.

Also, usually i use the Arduino UNO at the planing and designing state and when done change to Arduino Pro Mini

Step 2: Used Libraries :

I used several of them :
1. For the capacitive touch i used the CapSense library.
2. For the OLED display i used several of them that requier each other :
SPI.h - The library is used to communicate over SPI protocol.
WIRE.h - Used to communicate over I2C protocol
Adafruit-GFX-Library - Used to work with the OLED display.
Adafruit_SSD1306 - Used for the monochrome OLED based on SSD1306 drivers.

Step 3: CODE :

#include

#include 
#include 
#include 
#include

#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

#define Red 7
#define Green 8
#define ResetB 6
#define Sensitive 20
#define delayRun 2000
#define blinkDelay 75

#if (SSD1306_LCDHEIGHT != 64)
#error("Height incorrect, please fix Adafruit_SSD1306.h!");
#endif

CapacitiveSensor   cs_4_2 = CapacitiveSensor(5, 4);       // 10M resistor between pins 4 & 2, pin 2 is sensor pin, add a wire and or foil if desired
CapacitiveSensor   cs_4_6 = CapacitiveSensor(3, 2);       // 10M resistor between pins 4 & 6, pin 6 is sensor pin, add a wire and or foil

boolean hold = false, runT = false;
long holdTime, stopWatch;
long total1 ;
long total2 ;
long calculator, blinkCount = 0, over;
int Hours, Minuts, Seconds, Tseconds;

void setup()
{
  cs_4_2.set_CS_AutocaL_Millis(0xFFFFFFFF);     // turn off autocalibrate on channel 1 - just as an example
  Serial.begin(9600);
  pinMode (Red, OUTPUT);
  pinMode (Green, OUTPUT);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(WHITE);
  display.setCursor(0,0);
}

void loop()
{
  // *** Read touch-sensors
  long total1 =  cs_4_2.capacitiveSensor(30);
  long total2 =  cs_4_6.capacitiveSensor(30);
  //display.clearDisplay();
  display.setCursor (0,0);
  display.print ("SPEEDsTACK");
  display.display();
  // *** A touch bouth sides
  if (total1 >= Sensitive && total2 >= Sensitive && hold == false) {
    digitalWrite (Green, HIGH);
    digitalWrite (Red, HIGH);
    holdTime = millis() + delayRun;
//    Serial.print ("holdTime = ");
    display.clearDisplay();
    display.setCursor (0,0);
    display.print ("SPEEDsTACK");
    display.setCursor(0,30);
    display.print ("--READY--");
    display.display();
    hold = true;
  }

  // *** Go green light after delay
  if (millis() >= holdTime && hold == true) {
    digitalWrite (Green, HIGH);
    digitalWrite (Red, LOW);
    display.clearDisplay();
    display.setCursor(10,30);
    display.print ("** GO **");
    display.display();
    while (hold == true) {
      //Serial.println ("hold loop");
      // *** Waiting for bouth untouched
      while (total1 >= Sensitive && total2 >= Sensitive && hold == true) {
        total1 =  cs_4_2.capacitiveSensor(30);
        total2 =  cs_4_6.capacitiveSensor(30);
        delay (10);
      }
      total1 =  cs_4_2.capacitiveSensor(30);
      total2 =  cs_4_6.capacitiveSensor(30);
      // *** Wating for re-touch
      while (total1 <= Sensitive || total2 <= Sensitive && hold == true) {
        if (runT == false) {
          Serial.println ("                  *** Zeroing ***");
          stopWatch = millis() + 10;
          runT = true;
          blinkCount = 0;
        }
        total1 =  cs_4_2.capacitiveSensor(30);
        total2 =  cs_4_6.capacitiveSensor(30);
        calculator = millis() - stopWatch;
        //display.clearDisplay();
        //display.setCursor(0,0);
        //display.print (calculator);
        //display.display();
        Hours = int(calculator / 3600000);
        over = calculator % 3600000;
        Minuts    = int(over / 60000);
        over = over % 60000;
        Seconds    = int(over / 1000);
        Tseconds   = over % 1000;
        display.clearDisplay();
        display.setCursor (0,0);
        display.print ("SPEEDsTACK");
        display.setCursor(0,30);
        display.print (Hours);
        display.print (":");
        display.print (Minuts);
        display.print (":");
        display.print (Seconds);
        display.print (":");
        display.println (Tseconds);
        display.display();
        if (calculator >= blinkCount + blinkDelay) {
          Serial.println ("***BlinK***");
          digitalWrite (Green, !digitalRead (Green));
          blinkCount = calculator;
        }
      }
      if (runT == true) {
        stopWatch = millis() - stopWatch;
        Hours = int(stopWatch / 3600000);
        over = stopWatch % 3600000;
        Minuts    = int(over / 60000);
        over = over % 60000;
        Seconds    = int(over / 1000);
        Tseconds   = over % 1000;
        display.clearDisplay();
        display.setCursor (0,0);
        display.print ("SPEEDsTACK");
        display.setCursor(0,30);
        display.print (Hours);
        display.print (":");
        display.print (Minuts);
        display.print (":");
        display.print (Seconds);
        display.print (":");
        display.println (Tseconds);
        display.display();
        hold = false;
        runT = false;
        digitalWrite (Green, LOW);
        blinkCount = millis();
        while (!digitalRead (ResetB)) {
          if (millis() >= blinkCount + blinkDelay) {
//            Serial.println ("***BlinK***");
            digitalWrite (Green, !digitalRead (Green));
            digitalWrite (Red, !digitalRead (Green));
            blinkCount = millis();
          }
        }
      }
    }
  }

  // *** A touch only one side
  if (total1 >= Sensitive && total2 <= Sensitive || total1 <= Sensitive && total2 >= Sensitive) {
    digitalWrite (Green, LOW);
    digitalWrite (Red, HIGH);
    hold = false;
    display.clearDisplay();
    display.setCursor (0,0);
    display.print ("SPEEDsTACK");
    display.setCursor(32,30);
    display.print ("<<<>>>");
    display.display();
    Serial.print (total1);
    Serial.print ("\t");
    Serial.println (total1);
    Serial.println ("ONE Touch");
  }

  //*** No touch at all
  if (total1 <= Sensitive && total2 <= Sensitive) {
    digitalWrite (Green, LOW);
    digitalWrite (Red, LOW);
    display.clearDisplay();
    display.setCursor (0,0);
    display.print ("SPEEDsTACK");
    hold = false;
    Serial.println ("NO Touch");
  }

  /*
  Serial.print(total1);                  // print sensor output 1
  Serial.print("\t");
  Serial.println(total2);                  // print sensor output 2
  */
  delay(10);                             // arbitrary delay to limit data to serial port
}