6-digit 7-segment LED Counter Display

I need a 6-digit 7-segment LED module to display time and found Sparkfun has an example sketch for 4-digit 7-segment LED display module. So I just modify the example sketch to meet my requirement. The photos taken cannot display actual image saw by human eyes.

Photos

Parts

Arduino Uno R3
6-digit 7-segment LED Display Module KYX-3662BS
Some Wires

LED Module Pinouts

Sketch

/*
 6-13-2011
 Spark Fun Electronics 2011
 Nathan Seidle

 Original used for 4-digit 7-segment LED module
 Modified by Befun Hung on Jan. 13, 2016 to Extend to 6-digit

 This code is public domain but you buy me a beer if you use this and we meet someday (Beerware license).

 4 digit 7 segment display:
 http://www.sparkfun.com/products/9483
 Datasheet: 
 http://www.sparkfun.com/datasheets/Components/LED/7-Segment/YSD-439AR6B-35.pdf

 This is an example of how to drive a 7 segment LED display from an ATmega without the use of current limiting resistors.
 This technique is very common but requires some knowledge of electronics - you do run the risk of dumping too 
 much current through the segments and burning out parts of the display. If you use the stock code you should be ok, but 
 be careful editing the brightness values.

 This code should work with all colors (red, blue, yellow, green) but the brightness will vary from one color to the next
 because the forward voltage drop of each color is different. This code was written and calibrated for the red color.

 This code will work with most Arduinos but you may want to re-route some of the pins.

 7 segments
 6 digits
 1 colon
 =
 14 pins required for full control 
 */

// LED module used in this example is KYX-3662BS which is common anode 
int digit1 = 11; // 6-digit 7-segment LED pin 1
int digit2 = 10; // 6-digit 7-segment LED pin 2
int digit3 = 9;  // 6-digit 7-segment LED pin 3
int digit4 = 6;  // 6-digit 7-segment LED pin 4
int digit5 = 2;  // 6-digit 7-segment LED pin 5
int digit6 = 12; // 6-digit 7-segment LED pin 6

//Pin mapping from Arduino to the ATmega DIP28 if you need it
//http://www.arduino.cc/en/Hacking/PinMapping
int segA = A1; // 6-digit 7-segment LED pin 14
int segB = 3;  // 6-digit 7-segment LED pin 13
int segC = 4;  // 6-digit 7-segment LED pin 12
int segD = 5;  // 6-digit 7-segment LED pin 11
int segE = A0; // 6-digit 7-segment LED pin 10
int segF = 7;  // 6-digit 7-segment LED pin  9
int segG = 8;  // 6-digit 7-segment LED pin  8

void setup() {                
  pinMode(segA, OUTPUT);
  pinMode(segB, OUTPUT);
  pinMode(segC, OUTPUT);
  pinMode(segD, OUTPUT);
  pinMode(segE, OUTPUT);
  pinMode(segF, OUTPUT);
  pinMode(segG, OUTPUT);

  pinMode(digit1, OUTPUT);
  pinMode(digit2, OUTPUT);
  pinMode(digit3, OUTPUT);
  pinMode(digit4, OUTPUT);
  pinMode(digit5, OUTPUT);
  pinMode(digit6, OUTPUT);
  
  pinMode(13, OUTPUT);
}

void loop() {
  
  //long startTime = millis();

  displayNumber(millis()/1000, 6);
  displayNumber(millis()/100000, 4);
  displayNumber(millis()/10000000, 2);

  //while( (millis() - startTime) < 2000) {
  //displayNumber(1217);
  //}
  //delay(1000);  
}

//Given a number, we display 10:22
//After running through the 4 numbers, the display is left turned off

//Display brightness
//Each digit is on for a certain amount of microseconds
//Then it is off until we have reached a total of 20ms for the function call
//Let's assume each digit is on for 1000us
//If each digit is on for 1ms, there are 4 digits, so the display is off for 16ms.
//That's a ratio of 1ms to 16ms or 6.25% on time (PWM).
//Let's define a variable called brightness that varies from:
//5000 blindingly bright (15.7mA current draw per digit)
//2000 shockingly bright (11.4mA current draw per digit)
//1000 pretty bright (5.9mA)
//500 normal (3mA)
//200 dim but readable (1.4mA)
//50 dim but readable (0.56mA)
//5 dim but readable (0.31mA)
//1 dim but readable in dark (0.28mA)

// displayNumber() has added i parameter to display only 2 digit on specific position
void displayNumber(int toDisplay, int i) {
#define DISPLAY_BRIGHTNESS  500

#define DIGIT_ON  HIGH
#define DIGIT_OFF  LOW

  long beginTime = millis();

  for(int digit = i ; digit > i-2 ; digit--) {
    // digitalWrite(13, HIGH);

    //Turn on a digit for a short amount of time
    switch(digit) {
    // case 0:
      // digitalWrite(13, HIGH);
      // break;
    case 1:
      digitalWrite(digit1, DIGIT_ON);
      break;
    case 2:
      digitalWrite(digit2, DIGIT_ON);
      break;
    case 3:
      digitalWrite(digit3, DIGIT_ON);
      break;
    case 4:
      digitalWrite(digit4, DIGIT_ON);
      break;
    case 5:
      digitalWrite(digit5, DIGIT_ON);
      break;
    case 6:
      digitalWrite(digit6, DIGIT_ON);
      break;
    }

    //Turn on the right segments for this digit
    lightNumber(toDisplay % 10);
    toDisplay /= 10;

    delayMicroseconds(DISPLAY_BRIGHTNESS); //Display this digit for a fraction of a second (between 1us and 5000us, 500 is pretty good)

    //Turn off all segments
    lightNumber(10); 

    //Turn off all digits
    digitalWrite(digit1, DIGIT_OFF);
    digitalWrite(digit2, DIGIT_OFF);
    digitalWrite(digit3, DIGIT_OFF);
    digitalWrite(digit4, DIGIT_OFF);
    digitalWrite(digit5, DIGIT_OFF);
    digitalWrite(digit6, DIGIT_OFF);
    digitalWrite(13, LOW);
  }

  while( (millis() - beginTime) < 10) ; //Wait for 20ms to pass before we paint the display again
}

//Given a number, turns on those segments
//If number == 10, then turn off number
void lightNumber(int numberToDisplay) {

#define SEGMENT_ON  LOW
#define SEGMENT_OFF HIGH

  switch (numberToDisplay){

  case 0:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_ON);
    digitalWrite(segF, SEGMENT_ON);
    digitalWrite(segG, SEGMENT_OFF);
    break;

  case 1:
    digitalWrite(segA, SEGMENT_OFF);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_OFF);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_OFF);
    digitalWrite(segG, SEGMENT_OFF);
    break;

  case 2:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_OFF);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_ON);
    digitalWrite(segF, SEGMENT_OFF);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 3:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_OFF);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 4:
    digitalWrite(segA, SEGMENT_OFF);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_OFF);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_ON);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 5:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_OFF);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_ON);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 6:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_OFF);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_ON);
    digitalWrite(segF, SEGMENT_ON);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 7:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_OFF);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_OFF);
    digitalWrite(segG, SEGMENT_OFF);
    break;

  case 8:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_ON);
    digitalWrite(segF, SEGMENT_ON);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 9:
    digitalWrite(segA, SEGMENT_ON);
    digitalWrite(segB, SEGMENT_ON);
    digitalWrite(segC, SEGMENT_ON);
    digitalWrite(segD, SEGMENT_ON);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_ON);
    digitalWrite(segG, SEGMENT_ON);
    break;

  case 10:
    digitalWrite(segA, SEGMENT_OFF);
    digitalWrite(segB, SEGMENT_OFF);
    digitalWrite(segC, SEGMENT_OFF);
    digitalWrite(segD, SEGMENT_OFF);
    digitalWrite(segE, SEGMENT_OFF);
    digitalWrite(segF, SEGMENT_OFF);
    digitalWrite(segG, SEGMENT_OFF);
    break;
  }
}

Arduino RF Wireless Message Display Using I2C LCD Keypad Shield

The function of this sketch is same as the sketch posted on May. 11, 2014, but using I2C LCD Keypad Shield as the output device.

Sketch

/*
SimpleReceiveI2CLCD
This sketch displays text strings received using VirtualWire
Connect the Receiver data pin to Arduino pin 11
Modified by Befun Hung on Nov. 09, 2014 
Use I2C LCD Keypad Shield as the output
*/

#include <VirtualWire.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
// #define BACKLIGHT_PIN 13
LiquidCrystal_I2C lcd(0x20); //Set the LCD I2C address
// LiquidCrystal_I2C lcd(0x38, BACKLIGHT_PIN, POSITIVE);

byte message[VW_MAX_MESSAGE_LEN]; // a buffer to store the incoming messages
byte messageLength = VW_MAX_MESSAGE_LEN; // the size of the message
unsigned long counter = 1;

void setup()
{
  // pinMode(BACKLIGHT_PIN, OUTPUT);
  // digitalWrite(BACKLIGHT_PIN, HIGH);
  // set up the LCD's number of columns and rows: 
  lcd.begin(16, 2); //initialize the lcd
  // Print a message to the LCD.
  lcd.home(); //go home
  lcd.print("Device is ready!");
  // 
  Serial.begin(9600);
  Serial.println("Device is ready");
  // Initialize the IO and ISR
  vw_setup(2000); // Bits per sec
  vw_rx_start(); // Start the receiver
}
void loop()
{
  if (vw_get_message(message, &messageLength)) // Non-blocking
  {
    lcd.clear();
    Serial.print(counter);
    Serial.print(": ");
    // set the cursor to column 0, line 1
    // (note: line 1 is the second row, since counting begins with 0):
    lcd.setCursor(0, 0);
    lcd.print(counter);
    lcd.print(":");
    lcd.setCursor(0,1);
    for (int i = 0; i < messageLength; i++)
    {
      Serial.write(message[i]);
      lcd.print(char(message[i]));
    }
    Serial.println();
    counter++;
  }
}

Arduino RF Wireless Message Display

As I am building the RF wireless power socket for home automation, I need a stand along tool to display any wireless received message. During the lab, I use Arduino serial monitor to monitor the message received once a second, error always happens at different time point as following screen shot shows. After disconnecting the Arduino Uno from PC to monitor message received by using LCD keypad shield as a stand along system, the error condition gone.
The RF wireless message display can be used to display the time on the NTP synchronized RTC clock (my projects during Aug 2013), so no additional time adjustment at display side is needed.

Parts Used

1. Arduino Uno R3
2. cheaphousetek LCD Keypad Shield
3. RF Receiver (described in Arduino Cookbook 14.1)

Connection

1. Stack LCD Key Keypad Upon Arduino Uno R3
2. RF Receiver Data Pin - Arduino Uno D11
3. RF Receiver Vcc - Arduino Uno 5V
4. RF Receiver Gnd - Arduino Uno Gnd

Photo

The sketch runs correctly with output to LCD shield for 247,610 times.

Sketch

/*
SimpleReceiveLCD
This sketch displays text strings received using VirtualWire
Connect the Receiver data pin to Arduino pin 11
*/
#include <VirtualWire.h>
// include the library code:
#include <LiquidCrystal.h>
byte message[VW_MAX_MESSAGE_LEN]; // a buffer to store the incoming messages
byte messageLength = VW_MAX_MESSAGE_LEN; // the size of the message
unsigned long counter = 1;
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
void setup()
{
  // set up the LCD's number of columns and rows: 
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("hello, world!");
  lcd.clear();
  Serial.begin(9600);
  Serial.println("Device is ready");
  // Initialize the IO and ISR
  vw_setup(2000); // Bits per sec
  vw_rx_start(); // Start the receiver
}
void loop()
{
  if (vw_get_message(message, &messageLength)) // Non-blocking
  {
    lcd.clear();
    Serial.print(counter);
    Serial.print(": ");
    // set the cursor to column 0, line 1
    // (note: line 1 is the second row, since counting begins with 0):
    lcd.setCursor(0, 0);
    lcd.print(counter);
    lcd.print(":");
    lcd.setCursor(0,1);
    for (int i = 0; i < messageLength; i++)
    {
      Serial.write(message[i]);
      lcd.print(char(message[i]));
    }
    Serial.println();
    counter++;
  }
}