Am ales un afisaj cu 4 cifre multiplexate, cu anod comun, fabricat de Luckylight, avand codul KW4-563ASA, pe care l-am cumparat de la TME.
Dupa ce am studiat datasheet-ul afisajului meu si am comparat cu programul original care comanda un afisaj cu pinii asezati altfel, am refacut conexiunile, inclusiv sketch-ul.
Dupa cum se observă, in această schemă nu se folosesc rezistente de limitare, ci se foloseste controlul curentului prin varierea factorului de umplere (PWM) pentru fiecare grup LED-uri.
6-13-2011
Spark Fun Electronics 2011
Nathan Seidle
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
4 digits
1 colon
=
12 pins required for full control
*/
// modified connexion by niq_ro from http://nicuflorica.blogspot.com
// for my Luckylight KW4-563ASA
// dataseet: http://www.tme.eu/ro/Document/dfc2efde2e22005fd28615e298ea2655/KW4-563XSA.pdf
int digit2 = 10; //PWM Display pin 9
int digit3 = 9; //PWM Display pin 8
int digit4 = 6; //PWM Display pin 6
//Pin mapping from Arduino to the ATmega DIP28 if you need it
//http://www.arduino.cc/en/Hacking/PinMapping
int segA = A1; //Display pin 11
int segB = 3; //Display pin 7
int segC = 4; //Display pin 4
int segD = 5; //Display pin 2
int segE = A0; //Display pin 1
int segF = 7; //Display pin 10
int segG = 8; //Display pin 5
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(13, OUTPUT);
}
void loop() {
//long startTime = millis();
displayNumber(millis()/1000);
//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
//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)
void displayNumber(int toDisplay) {
#define DISPLAY_BRIGHTNESS 500
#define DIGIT_ON HIGH
#define DIGIT_OFF LOW
long beginTime = millis();
for(int digit = 4 ; digit > 0 ; digit--) {
//Turn on a digit for a short amount of time
switch(digit) {
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;
}
//Turn on the right segments for this digit
lightNumber(toDisplay % 10);
toDisplay /= 10;
delayMicroseconds(DISPLAY_BRIGHTNESS);
//Display digit for fraction of a second (1us to 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);
}
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;
}
}
Am facut un film demonstrativ, care se numeste counter with 7 segment LED and Arduino
Articole interesante si cu explicatii se gasesc la:
- hacktronics.com
Pentru a putea folosi la maxim modul de afisare al acestui tip de afisaj cu cifre de 7 segmente conectate pentru comanda multiplexata, se utilizeaza libraria SevSeg.
Niciun comentariu:
Trimiteți un comentariu