模块图片,4位共阳极数码管.

我们使用树莓派wiringPi的库来通过74HC595驱动4位数码管:

C 代码如下: 

1 #include 
     
       2 #include 
      
        3 #include 
       
         4 #include 
        
          5 #include 
         
           6 #define SCLK 12 7 #define RCLK 13 8 #define DIO 14 9 unsigned int code_char[]={
   0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};10 unsigned char code_segbit[]={
   0x01,0x02,0x04,0x08};11 int pins[3]={SCLK,RCLK,DIO};12 int init(){13     int i=0;14     for(i=0;i<3;i++){15     pinMode(pins[i],OUTPUT);16     digitalWrite(pins[i],LOW);17     }18 }19 20 int destroy(){21     int i=0;22     for(i=0;i<3;i++){23     digitalWrite(pins[i],LOW);24     pinMode(pins[i],INPUT);25     }26 }27 28 void loop(){29     time_t rawtime;30     time(&rawtime);31     struct tm *timeinfo;32     timeinfo=localtime(&rawtime);33     digitalWrite(RCLK,LOW);34     if(timeinfo->tm_min>=10)shiftOut(DIO,SCLK,1,code_char[timeinfo->tm_min%10]);//character35     else shiftOut(DIO,SCLK,1,code_char[timeinfo->tm_min]);36     shiftOut(DIO,SCLK,1,code_segbit[0]);//bit37     digitalWrite(RCLK,HIGH);38     digitalWrite(RCLK,LOW);39     if(timeinfo->tm_min>=10)shiftOut(DIO,SCLK,1,code_char[timeinfo->tm_min/10]);//character40     else shiftOut(DIO,SCLK,1,code_char[0]);41     shiftOut(DIO,SCLK,1,code_segbit[1]);//bit42     digitalWrite(RCLK,HIGH);43     digitalWrite(RCLK,LOW);44     if(timeinfo->tm_hour>=10)shiftOut(DIO,SCLK,1,code_char[timeinfo->tm_hour%10]);//character45     else shiftOut(DIO,SCLK,1,code_char[timeinfo->tm_hour]);46     shiftOut(DIO,SCLK,1,code_segbit[2]);//bit47     digitalWrite(RCLK,HIGH);48     digitalWrite(RCLK,LOW);49     if(timeinfo->tm_hour>=10)shiftOut(DIO,SCLK,1,code_char[timeinfo->tm_hour/10]);//character50     else shiftOut(DIO,SCLK,1,code_char[0]);51     shiftOut(DIO,SCLK,1,code_segbit[3]);//bit52     digitalWrite(RCLK,HIGH);53     //printf("%d %d\t%d %d %d %d\n",54     // timeinfo->tm_hour,timeinfo->tm_min,55     // timeinfo->tm_hour/10,timeinfo->tm_hour%10,56     // timeinfo->tm_min/10,timeinfo->tm_min%10);57     delayMicroseconds(10);58 }59 60 int main(void){61     if(wiringPiSetup()==-1) //wiringPiSetupGpio==BCM62         exit(1);63     init();64     while(1) {65         loop();66     }67     destroy();68     return 0;69 }
         
        
       
      
     

 

74HC595.h

1 /* 2  * wiringShift.h: 3  *    Emulate some of the Arduino wiring functionality.  4  * 5  * Copyright (c) 2009-2012 Gordon Henderson. 6  *********************************************************************** 7  * This file is part of wiringPi: 8  *    https://projects.drogon.net/raspberry-pi/wiringpi/ 9  *10  *    wiringPi is free software: you can redistribute it and/or modify11  *    it under the terms of the GNU Lesser General Public License as published by12  *    the Free Software Foundation, either version 3 of the License, or13  *    (at your option) any later version.14  *15  *    wiringPi is distributed in the hope that it will be useful,16  *    but WITHOUT ANY WARRANTY; without even the implied warranty of17  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the18  *    GNU Lesser General Public License for more details.19  *20  *    You should have received a copy of the GNU Lesser General Public License21  *    along with wiringPi.  If not, see 
     .22  ***********************************************************************23  */24 25 #define    LSBFIRST    026 #define    MSBFIRST    127 28 #ifndef    _STDINT_H29 # include 
     
      30 #endif31 32 #ifdef __cplusplus33 extern "C" {34 #endif35 36 extern uint8_t shiftIn      (uint8_t dPin, uint8_t cPin, uint8_t order) ;37 extern void    shiftOut     (uint8_t dPin, uint8_t cPin, uint8_t order, uint8_t val) ;38 39 #ifdef __cplusplus40 }41 #endif
     

 

74HC595.C

1 /* 2  * wiringShift.c: 3  *    Emulate some of the Arduino wiring functionality.  4  * 5  * Copyright (c) 2009-2012 Gordon Henderson. 6  *********************************************************************** 7  * This file is part of wiringPi: 8  *    https://projects.drogon.net/raspberry-pi/wiringpi/ 9  *10  *    wiringPi is free software: you can redistribute it and/or modify11  *    it under the terms of the GNU Lesser General Public License as published by12  *    the Free Software Foundation, either version 3 of the License, or13  *    (at your option) any later version.14  *15  *    wiringPi is distributed in the hope that it will be useful,16  *    but WITHOUT ANY WARRANTY; without even the implied warranty of17  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the18  *    GNU Lesser General Public License for more details.19  *20  *    You should have received a copy of the GNU Lesser General Public License21  *    along with wiringPi.  If not, see 
     .22  ***********************************************************************23  */24 25 #include 
     
      26 #include "wiringPi.h"27 #include "wiringShift.h"28 29 /*30  * shiftIn:31  *    Shift data in from a clocked source32  *********************************************************************************33  */34 35 uint8_t shiftIn (uint8_t dPin, uint8_t cPin, uint8_t order)36 {37   uint8_t value = 0 ;38   int8_t  i ;39  40   if (order == MSBFIRST)41     for (i = 7 ; i >= 0 ; --i)42     {43       digitalWrite (cPin, HIGH) ;44       value |= digitalRead (dPin) << i ;45       digitalWrite (cPin, LOW) ;46     }47   else48     for (i = 0 ; i < 8 ; ++i)49     {50       digitalWrite (cPin, HIGH) ;51       value |= digitalRead (dPin) << i ;52       digitalWrite (cPin, LOW) ;53     }54 55   return value;56 }57 58 /*59  * shiftOut:60  *    Shift data out to a clocked source61  *********************************************************************************62  */63 void shiftOut (uint8_t dPin, uint8_t cPin, uint8_t order, uint8_t val)64 {65   int8_t i;66   if (order == MSBFIRST)67     for (i = 7 ; i >= 0 ; --i)68     {69       digitalWrite (dPin, val & (1 << i)) ;70       digitalWrite (cPin, HIGH) ;71       digitalWrite (cPin, LOW) ;72     }73   else74     for (i = 0 ; i < 8 ; ++i)75     {76       digitalWrite (dPin, val & (1 << i)) ;77       digitalWrite (cPin, HIGH) ;78       digitalWrite (cPin, LOW) ;79     }80 }