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;
}
}
