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Using a 7 segment 4 digit display with OP 看全部

Edited by AFT at 2017-3-11 05:36

Hey Guys,

I've got a 7 segment 4 digit display (Common anode configuration), and I want to use the Orange Pi to drive it. I've got the wiringPi installed and I'm using Python.

Are there any tutorials for a beginner like me?

Edited by nopnop2002 at 2017-3-12 07:24

It'll be as follows by a C language.
You must be change segmentDigits according to the device you use.

example for 8 segments 3 digits.

common pin : GPIO10-12
segment led pin : GPIO0-7

  1. // 8segment anode led test
  2. #include <stdio.h>
  3. #include <stdlib.h>
  4. #include <wiringPi.h>
  5. #include <string.h>
  6. #include <stdint.h>

  8. #define Pins    8
  9. #define P0      0
  10. #define Digs    3
  11. #define D0      10

  13. static const uint8_t segmentDigits [] =
  14. {
  15. // a  b  c  d  e  f  g  p    Segments
  16. // 0  1  2  3  4  5  6  7    wiringPi pin No.
  17.    1, 1, 1, 1, 1, 1, 0, 0,    // 0
  18.    0, 1, 1, 0, 0, 0, 0, 0,    // 1
  19.    1, 1, 0, 1, 1, 0, 1, 0,    // 2
  20.    1, 1, 1, 1, 0, 0, 1, 0,    // 3
  21.    0, 1, 1, 0, 0, 1, 1, 0,    // 4
  22.    1, 0, 1, 1, 0, 1, 1, 0,    // 5
  23.    1, 0, 1, 1, 1, 1, 1, 0,    // 6
  24.    1, 1, 1, 0, 0, 0, 0, 0,    // 7
  25.    1, 1, 1, 1, 1, 1, 1, 0,    // 8
  26.    1, 1, 1, 1, 0, 1, 1, 0,    // 9
  27.    1, 1, 1, 0, 1, 1, 1, 0,    // A
  28.    0, 0, 1, 1, 1, 1, 1, 0,    // b
  29.    1, 0, 0, 1, 1, 1, 0, 0,    // C
  30.    0, 1, 1, 1, 1, 0, 1, 0,    // d
  31.    1, 0, 0, 1, 1, 1, 1, 0,    // E
  32.    1, 0, 0, 0, 1, 1, 1, 0,    // F
  33.    0, 0, 0, 0, 0, 0, 0, 0,    // blank
  34. } ;


  37. DisplayDigits (char* digits)
  38. {
  39.     int i;
  40.     uint8_t digit, segment ;
  41.     uint8_t index, d, segVal ;

  43.     for (digit = 0 ; digit < Digs; ++digit) {
  44.       digitalWrite (D0 + digit, 1) ;
  45.       d = toupper (digits [digit]) ;
  46.       if ((d >= '0') && (d <= '9'))           // Digit
  47.       index = d - '0' ;
  48.       else if ((d >= 'A') && (d <= 'F'))    // Hex
  49.       index = d - 'A' + 10 ;
  50.       else
  51.       index = 16 ;                             // Blank
  52.       for (segment = 0 ; segment < 8 ; ++segment) {
  53.         segVal = segmentDigits [index * 8 + segment] ;
  54.         digitalWrite (segment+P0, !segVal) ;
  55. //when add delay,you can understand how to work
  56. //        delay(1000);
  57.         delayMicroseconds (100) ;
  58.         digitalWrite (segment+P0, 1) ;
  59.       }
  60.       digitalWrite (D0 + digit, 0) ;
  61.     }
  62. }

  64. int main (void)
  65. {
  66.     int i;
  67.     char digits [8] ;

  69.     if(wiringPiSetup() == -1) return 1;
  70.     for(i=0;i<Pins;i++) {
  71.         pinMode(P0+i, OUTPUT);
  72.         digitalWrite(P0+i, 0);
  73.     }
  74.     for(i=0;i<Digs;i++) {
  75.         pinMode(D0+i, OUTPUT);
  76.         digitalWrite(D0+i, 0);
  77.     }

  79.     strcpy(digits,"123");
  80.     for(i=0;i<3000;i++) DisplayDigits(digits);

  82.     strcpy(digits,"ABC");
  83.     for(i=0;i<3000;i++) DisplayDigits(digits);

  85.     for(i=0;i<Pins;i++) {
  86.         digitalWrite(P0+i, 0);
  87.     }
  88.     for(i=0;i<Digs;i++) {
  89.         digitalWrite(D0+i, 0);
  90.     }
  91.     exit;
  92. }



  • Bench AFT
  • 2017-3-15 00:48:14
quote: nopnop2002 replied at 2017-3-12 07:18
It'll be as follows by a C language.
You must be change segmentDigits according to the device you us ...

Thanks, Your code worked. I found another one in python

  1. from pyA20.gpio import gpio
  2. from pyA20.gpio import port
  3. from time import sleep
  4. import time

  6. gpio.init()

  8. segments =  (port.PA12,port.PA6,port.PA8,port.PA11,port.PC3,port.PA21,port.PC1,port.PA7)

  10. for segment in segments:
  11.     gpio.setcfg(segment, gpio.OUTPUT)
  12.     gpio.output(segment, 1)

  14. digits = (port.PG8,port.PC0,port.PC2,port.PA9)

  16. for digit in digits:
  17.     gpio.setcfg(digit, gpio.OUTPUT)
  18.     gpio.output(digit, 0)

  20. num = {' ':(1,1,1,1,1,1,1,1),
  21.     '0':(0,0,1,0,1,0,0,0),
  22.     '1':(1,1,1,0,1,0,1,1),
  23.     '2':(0,0,1,1,0,0,1,0),
  24.     '3':(1,0,1,0,0,0,1,0),
  25.     '4':(1,1,1,0,0,0,0,1),
  26.     '5':(1,0,1,0,0,1,0,0),
  27.     '6':(0,0,1,0,0,1,0,0),
  28.     '7':(1,1,1,0,1,0,0,0),
  29.     '8':(0,0,1,0,0,0,0,0),
  30.     '9':(1,0,1,0,0,0,0,0)}

  32. try:
  33.     while True:
  34.         n = time.ctime()[11:13]+time.ctime()[14:16]
  35.         s = str(n).rjust(4)
  36.         for digit in range(4):
  37.             for loop in range(0,8):
  38.                 gpio.output(segments[loop], num[s[digit]][loop])
  39.                 if (int(time.ctime()[18:19])%2 == 0) and (digit == 1):
  40.                     gpio.output(port.PA8, 0)
  41.                 else:
  42.                     gpio.output(port.PA8, 1)
  43.             gpio.output(digits[digit], 1)
  44.             time.sleep(0.005)
  45.             gpio.output(digits[digit], 0)
  46.                        
  47. finally:
  48.     print("done")
This one shows time on the screen.

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