Clock Video

Here is a short video of the clock prototype in action

Working Prototype

Here is my working Prototype

It is hard to get a good picture of the displays.

The clock on the left is counting down.  The button on the left is lit indicating which player is on the move.  I will try to post a video soon.

Making all of the wiring cables, and soldering everything to the perf board took a lot more time than I had expected.

Plastic Prototype Enclosure

It is time to move off the breadboards and into the prototype in a box phase.   I bought a plastic storage box for about $4.  It is made from polypropylene which is easy to cut.  I drilled 1 inch holes in the bottom for the two lighted switches, and cut a large rectangle in the side for the displays.

This box is much larger than the final wood version will be.  The wood version will be shaped much more like a Chronos; a bit wider, lower and narrower, with a sloped front for the displays.  I also plan to use mechanical plungers instead of the buttons, but this will work for the prototype.  These buttons have an LED inside that I will use to indicate who is to move.  The sides of this box are transparent, so I won't have to open the box to show off the electronics inside.

Next step is to make wiring harnesses for the displays.  The headers on the displays have male pins spaced 0.1 inches.  This page has instructions for building the wiring harness.  Since the displays only use 12 of the 16 pins, and they are in groups of 6, I will likely use two 6 pin housings for each display.  I can get all the parts at the local electronics shop.

More pictures to follow.

It's a Clock !

I've got the basic clock sending time output to the displays.  The LEDs show who is on move, and the buttons switch the clocks and LEDs.

What is left to do (software):
- move counter
- increment and delay
- multiple periods
- Setup routine for setting time and choosing options using buttons
- save settings to non-volatile memory

What is left to do (hardware)
- switches (on/off and pause)
- 4 buttons for navigating the menus
- prototype case, probably plastic
- eventually a nice wooden case, with mechanical plungers.


Sketch Update

I modified the printTime() function to convert the time remaining for each player from 1/10 seconds to H:MM:SS and to write that to the displays, by calling a new writeNum() function.

// Function to write the time to the displays
void printTime() {                      // print time function
  int secDis1;
  int secDis10;
  int minDis1;
  int minDis10;
  int hrDis1;
  int secs;
  
  secs = timeR1 / 10;                  // convert 1/10 sec to H:MM:SS
  hrDis1 = secs / 3600;
  secs = secs % 3600;
  minDis10 = secs / 600;
  secs = secs % 600;
  minDis1 = secs / 60;
  secs = secs % 60;
  secDis10 = secs / 10;
  secDis1 = secs % 10;
  
  writeNum(hrDis1,3,1);
  writeNum(minDis10,7,1);
  writeNum(minDis1,10,1);
  writeNum(secDis10,14,1);
  writeNum(secDis1,17,1);
  
  secs = timeR2 / 10;                  // convert 1/10 sec to H:MM:SS
  hrDis1 = secs / 3600;
  secs = secs % 3600;
  minDis10 = secs / 600;
  secs = secs % 600;
  minDis1 = secs / 60;
  secs = secs % 60;
  secDis10 = secs / 10;
  secDis1 = secs % 10;
  
  writeNum(hrDis1,3,2);
  writeNum(minDis10,7,2);
  writeNum(minDis1,10,2);
  writeNum(secDis10,14,2);
  writeNum(secDis1,17,2); 
}

Part of the writeNum() function:

// function to write digits to the displays
void writeNum(int charDigit, int charPos, int turn){
   switch (charDigit){
      case 0:
         if (turn==1){
           lcd1.setCursor(charPos,0);
           lcd1.write(1);
           lcd1.write(2);
           lcd1.write(2);
           lcd1.setCursor(charPos,1);
           lcd1.write(3);
           lcd1.write(32);
           lcd1.write(3);
           lcd1.setCursor(charPos,2);
           lcd1.write(3);
           lcd1.write(32);
           lcd1.write(3);
           lcd1.setCursor(charPos,3);
           lcd1.write(3);
           lcd1.write(2);
           lcd1.write(4);
         }
         else{
           lcd2.setCursor(charPos,0);
           lcd2.write(1);
           lcd2.write(2);
           lcd2.write(2);
           lcd2.setCursor(charPos,1);
           lcd2.write(3);
           lcd2.write(32);
           lcd2.write(3);
           lcd2.setCursor(charPos,2);
           lcd2.write(3);
           lcd2.write(32);
           lcd2.write(3);
           lcd2.setCursor(charPos,3);
           lcd2.write(3);
           lcd2.write(2);
           lcd2.write(4); 
         }
         break;

and this continues for each of the 10 digits, plus a blank space if I want to use that later.

Functioning Clock and BIG NUMBERS

Working Chess Clock

I now have a functioning chess clock.  Lots of work yet to be done, but the basic functions are all working.

I took the code from the earlier clock test, and changed it from sending the output to the serial port, to writing the time to the displays.  I also made the updates every 1/10 second.

This picture shows the two buttons and the green LEDs which indicate whose turn it is to move:

The buttons are wired to pins 2 and 3, with 10 K ohm pull-up resistors to +5V.  Closing the switch pulls the pin to ground.

The LED anodes are connected to pins 4 and 5, with 560 ohm resistors between the cathode and ground.  (similar to the schematics published earlier, but the pins have changed).

This next picture shows the display for player 2.  Note, it is counting down tenths of seconds.

I will attach the sketch at the bottom of this post.


Big Numbers

I also did some work on making large numbers for the time display.  (I don't know why this blog page insists on turning the image sideways, it is horizontal on my PC, but you can still see the large digits).

These large numbers were made by combining 7 custom characters.  The custom characters are numbered 0 through 7, but I used 1 through 7 because those were the numbers I used when I drew out the patterns on graph paper.  Note, if you use character 0, the data type must be declared something like this:  lcd.write((byte)0);   It has something to do with control codes vs. custom characters.  Luckily, since I used 1-7, I didn't run into this issue, but read about it on other web pages.

Some pieces of the sketch that created these large numbers:

#include <LiquidCrystal.h>
LiquidCrystal lcd1(6,7,9,10,11,12);
LiquidCrystal lcd2(6,8,9,10,11,12);

// create bit maps of the custom characters.  5 columns by 8 rows.
byte customChar1[8] = {
  B00000,
  B00000,
  B00000,
  B00000,
  B00011,
  B00011,
  B00011,
  B00011
};
.
.
.

void setup() {
   lcd1.begin(20, 4);
   lcd2.begin(20, 4);
   lcd1.createChar(1,customChar1);   //  assign the bitmap pattern to character 1
   .
   .
   .
}

void loop() {
   lcd1.setCursor(3,0);
   lcd1.write(1);     // write character 1
   .
   .
   .
}


And now, my most up to date clock sketch (from the photos at the top of this post):

//   
//  Chess Clock Practice Sketches
//
//  Bob Nolan
//  3/26/2015
//

// Include LCD display library and set up pinouts
#include <LiquidCrystal.h>
LiquidCrystal lcd1(6,7,9,10,11,12);
LiquidCrystal lcd2(6,8,9,10,11,12);

// Declare Global Variables
unsigned int timeR1;
unsigned int timeR2;
unsigned long lastMilliS;
int turn;
int ledPin1 = 4;
int ledPin2 = 5;
int switchPin1 = 2;
int switchPin2 = 3;
boolean checkButton;
boolean flag1=0;
boolean flag2=0;

void setup() {
  timeR1 = 150;                // set initial time.  Time is in 1/10 sec
  timeR2 = 150;                // need to add user input routine
  turn=0;
  pinMode(ledPin1,OUTPUT);
  pinMode(ledPin2,OUTPUT);
  pinMode(switchPin1,INPUT);
  pinMode(switchPin2,INPUT);
  lcd1.begin(20,4);
  lcd2.begin(20,4);
  lcd1.print("Player 1");
  lcd2.print("Player 2");
}

void loop() {  
 if (turn==0){              // dont start counting until 1st button press
    lastMilliS=millis();
 }
  if (millis()-lastMilliS >= 100) {   // every 100 msec, update time
    lastMilliS=millis();
    if((turn==1)&&(!flag1)){
      timeR1--;
    }
    if((turn==2)&&(!flag2)){
      timeR2--;
    }
    printTime();
  }
  checkButton=digitalRead(switchPin1);   // player 1 button press
  if(!checkButton && (turn!=2)){
    digitalWrite(ledPin2,HIGH);
    digitalWrite(ledPin1,LOW);
    turn = 2;
    printTime();
    
  }
  checkButton=digitalRead(switchPin2);   // player 2 button press
  if(!checkButton && (turn!=1)){
    digitalWrite(ledPin1,HIGH);
    digitalWrite(ledPin2,LOW);
    turn = 1;
    printTime();
   
  }
  if((timeR1<=0)&&(!flag1)){            // player 1 flag
    lcd1.setCursor(0,2);
    lcd1.print("Flag");
    flag1=1;
  }
  if((timeR2==0)&&(!flag2)){            // player 2 flag
    lcd2.setCursor(0,2);
    lcd2.print("Flag");
    flag2=1;    
  }
}

void printTime() {                      // print time function
   lcd1.setCursor(0,1);
   lcd1.print(timeR1);
   lcd1.print("  ");
   lcd2.setCursor(0,1);
   lcd2.print(timeR2);
   lcd2.print("  ");
}

More progress with the displays

I have both displays hooked up and working independently now, and like I had hoped, it only takes 7 output pins to drive both displays.

Here is how they are wired

LCD Pin	Arduino Pin
1 Logic Gnd	Gnd
2 Logic +5V	+5V
3 Contrast	Pot sweep
4 RS	Pin 6
5 RW	Gnd
6 EN (LCD1)	Pin 7
6 EN (LCD 2)	Pin 8
7
8
9
10
11 DB4	Pin 9
12 DB5	Pin 10
13 DB6	Pin 11
14 DB7	Pin 12
15 Backlight +5V	+5V
16 Backlight Gnd	Gnd

I used one potentiometer to control the contrast on both displays.  All of the connections go to both displays except the enable which has pin 7 going to display 1 and pin 8 going to display 2.

Sample Sketch

I used the following sketch to test that I had both displays wired correctly.  Notice that I had to define the pinouts for LCD1 and LCD2.

#include <LiquidCrystal.h>

LiquidCrystal lcd1(6,7,9,10,11,12);

LiquidCrystal lcd2(6,8,9,10,11,12);

void setup() {

  // put your setup code here, to run once:

lcd1.begin(20, 4);

lcd2.begin(20, 4);

 lcd1.print("Player 1");

 lcd2.print("Player 2");

}

void loop() {

  // put your main code here, to run repeatedly:

 lcd1.setCursor(0,1);

 lcd1.print(millis()/1000);

 delay(1000);

 lcd2.setCursor(0,1);

 lcd2.print(millis()/1000);

 delay(1000);

}

Phase 3 - Integrate the displays

Phase 3 has begun!

The displays arrived today.  First I soldered on the headers.  It has probably been 25 years since I did any precise soldering so it doesn't look like a professional job, but it works.  I tested each connection with my ohm meter to make sure I had a good contact and wasn't shorted to the next pin over.

Next I followed the tutorial from the Adafruit website to wire up the displays.  Then loaded the "Hello World" example.  I swapped the displays to make sure both were working correctly.  That was quicker than running another set of jumpers.

Next steps:
- update my clock sketch to send the time to the displays
- figure out how to do my custom characters for the large digits
- polish up the sketch and add delay, increment, and multiple periods
- create a setup routine so the time and other settings can be set with button presses

I'll post more updates as I make progress.