原材料：树莓派zero×1、东德产RFT Z750M辉光管×4、ds1302时钟模块×1、K155ID1×1、5v升170v升压模块×1
辉光管工作原理：和普通的灯泡类似，辉光管内有10个铁片，分别是1-10十个数字，接通哪个就亮哪个，不过这种灯需要高压并限流，需要在电路上注意一下。
170v电压的获得与限流：5v升170v的模块可以从淘宝上轻易获得，这里用5v升压的原因是可以直接从树莓派上取得需要的电压，并且不建议自己DIY升压电路，可能会烧毁树莓派。至于限流，直接加电阻就可以了，我这里用的是20kΩ的电阻。之后阳极连170v加电阻，随便接一根阴极，辉光管就能亮起来了。
辉光管的驱动：因为每一只辉光管都有10+1=11只引脚，树莓派的GPIO肯定是不够用来控制四只辉光管，并且辉光管所需要的高压对树莓派来说也是一个问题，所以需要K155ID1译码器来控制每一只辉光管。下面是该译码器的引脚定义和真值表，需要输出哪个数字就可以在相应的引脚加上需要的高低电平，这样就解决了辉光管的驱动问题。
时间的获取与保存：众所周知，树莓派可以连接wifi进行时间的同步，但是断电后时间不能继续流逝，这就需要ds1302模块进行时间的存储，这里我们可以直接使用WiringPi自带的驱动程序对模块进行操作。文件位置在 WiringPi 安装包的 examples/ds1302.c，代码如下
/*
* ds1302.c:
* Real Time clock
*
* Copyright (c) 2013 Gordon Henderson.
***********************************************************************
* This file is part of wiringPi:
* https://projects.drogon.net/raspberry-pi/wiringpi/
*
* wiringPi is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* wiringPi is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with wiringPi. If not, see <http://www.gnu.org/licenses/>.
***********************************************************************
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <time.h>
#include <wiringPi.h>
#include <ds1302.h>
// Register defines
#define RTC_SECS 0
#define RTC_MINS 1
#define RTC_HOURS 2
#define RTC_DATE 3
#define RTC_MONTH 4
#define RTC_DAY 5
#define RTC_YEAR 6
#define RTC_WP 7
#define RTC_TC 8
#define RTC_BM 31
static unsigned int masks [] = { 0x7F, 0x7F, 0x3F, 0x3F, 0x1F, 0x07, 0xFF } ;
/*
* bcdToD: dToBCD:
* BCD decode/encode
*********************************************************************************
*/
static int bcdToD (unsigned int byte, unsigned int mask)
{
unsigned int b1, b2 ;
byte &= mask ;
b1 = byte & 0x0F ;
b2 = ((byte >> 4) & 0x0F) * 10 ;
return b1 + b2 ;
}
static unsigned int dToBcd (unsigned int byte)
{
return ((byte / 10) << 4) + (byte % 10) ;
}
/*
* ramTest:
* Simple test of the 31 bytes of RAM inside the DS1302 chip
*********************************************************************************
*/
static int ramTestValues [] =
{ 0x00, 0xFF, 0xAA, 0x55, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x00, 0xF0, 0x0F, -1 } ;
static int ramTest (void)
{
int addr ;
int got ;
int i = 0 ;
int errors = 0 ;
int testVal ;
printf ("DS1302 RAM TEST\n") ;
testVal = ramTestValues [i] ;
while (testVal != -1)
{
for (addr = 0 ; addr < 31 ; ++addr)
ds1302ramWrite (addr, testVal) ;
for (addr = 0 ; addr < 31 ; ++addr)
if ((got = ds1302ramRead (addr)) != testVal)
{
printf ("DS1302 RAM Failure: Address: %2d, Expected: 0x%02X, Got: 0x%02X\n",
addr, testVal, got) ;
++errors ;
}
testVal = ramTestValues [++i] ;
}
for (addr = 0 ; addr < 31 ; ++addr)
ds1302ramWrite (addr, addr) ;
for (addr = 0 ; addr < 31 ; ++addr)
if ((got = ds1302ramRead (addr)) != addr)
{
printf ("DS1302 RAM Failure: Address: %2d, Expected: 0x%02X, Got: 0x%02X\n",
addr, addr, got) ;
++errors ;
}
if (errors == 0)
printf ("-- DS1302 RAM TEST: OK\n") ;
else
printf ("-- DS1302 RAM TEST FAILURE. %d errors.\n", errors) ;
return 0 ;
}
/*
* setLinuxClock:
* Set the Linux clock from the hardware
*********************************************************************************
*/
static int setLinuxClock (void)
{
char dateTime [20] ;
char command [64] ;
int clock [8] ;
printf ("Setting the Linux Clock from the DS1302... ") ; fflush (stdout) ;
ds1302clockRead (clock) ;
// [MMDDhhmm[[CC]YY][.ss]]
sprintf (dateTime, "%02d%02d%02d%02d%02d%02d.%02d",
bcdToD (clock [RTC_MONTH], masks [RTC_MONTH]),
bcdToD (clock [RTC_DATE], masks [RTC_DATE]),
bcdToD (clock [RTC_HOURS], masks [RTC_HOURS]),
bcdToD (clock [RTC_MINS], masks [RTC_MINS]),
20,
bcdToD (clock [RTC_YEAR], masks [RTC_YEAR]),
bcdToD (clock [RTC_SECS], masks [RTC_SECS])) ;
sprintf (command, "/bin/date %s", dateTime) ;
system (command) ;
return 0 ;
}
/*
* setDSclock:
* Set the DS1302 block from Linux time
*********************************************************************************
*/
static int setDSclock (void)
{
struct tm* t = NULL ;
time_t now ;
int clock [8] ;
printf ("Setting the clock in the DS1302 from Linux time... ") ;
now = time (NULL) ;
//gmtime_r (&now, &t) ;
t = localtime(&now);
clock [ 0] = dToBcd (t->tm_sec) ; // seconds
clock [ 1] = dToBcd (t->tm_min) ; // mins
clock [ 2] = dToBcd (t->tm_hour) ; // hours
clock [ 3] = dToBcd (t->tm_mday) ; // date
clock [ 4] = dToBcd (t->tm_mon + 1) ; // months 0-11 --> 1-12
clock [ 5] = dToBcd (t->tm_wday + 1) ; // weekdays (sun 0)
clock [ 6] = dToBcd (t->tm_year - 100) ; // years
clock [ 7] = 0 ; // W-Protect off
ds1302clockWrite (clock) ;
printf ("OK\n") ;
return 0 ;
}
int main (int argc, char *argv [])
{
int i ;
int clock [8] ;
wiringPiSetup () ;
ds1302setup (14, 30, 10) ;
//此处填写ds1302模块对应的管脚
if (argc == 2)
{
/**/ if (strcmp (argv [1], "-slc") == 0)
return setLinuxClock () ;
else if (strcmp (argv [1], "-sdsc") == 0)
return setDSclock () ;
else if (strcmp (argv [1], "-rtest") == 0)
return ramTest () ;
else
{
printf ("Usage: ds1302 [-slc | -sdsc | -rtest]\n") ;
return EXIT_FAILURE ;
}
}
for (i = 0 ;; ++i)
{
printf ("%5d: ", i) ;
ds1302clockRead (clock) ;
printf (" %2d:%02d:%02d",
bcdToD (clock [2], masks [2]), bcdToD (clock [1], masks [1]), bcdToD (clock [0], masks [0])) ;
printf (" %2d/%02d/%04d",
bcdToD (clock [3], masks [3]), bcdToD (clock [4], masks [4]), bcdToD (clock [6], masks [6]) + 2000) ;
printf ("\n") ;
delay (200) ;
}
return 0 ;
}
以下是辉光管驱动程序
# coding=utf-8
import time
import datetime
import RPi.GPIO
# 定义单个辉光管各段led对应的GPIO口
L = [[12, 20, 21, 16], [26, 13, 6, 19], [22, 17, 4, 27], [18, 24, 25, 23]]
RPi.GPIO.setmode(RPi.GPIO.BCM)
for i in range(0, 4):
for j in range(0, 4):
RPi.GPIO.setup(L[i][j], RPi.GPIO.OUT)
# 指定no(1-4)号辉光管显示数字num(0-9)
def showDigit(no, num):
if (no):
if (num == 0):
RPi.GPIO.output(L[no - 1][0], False)
RPi.GPIO.output(L[no - 1][1], False)
RPi.GPIO.output(L[no - 1][2], False)
RPi.GPIO.output(L[no - 1][3], False)
elif (num == 1):
RPi.GPIO.output(L[no - 1][0], True)
RPi.GPIO.output(L[no - 1][1], False)
RPi.GPIO.output(L[no - 1][2], False)
RPi.GPIO.output(L[no - 1][3], False)
elif (num == 2):
RPi.GPIO.output(L[no - 1][0], False)
RPi.GPIO.output(L[no - 1][1], True)
RPi.GPIO.output(L[no - 1][2], False)
RPi.GPIO.output(L[no - 1][3], False)
elif (num == 3):
RPi.GPIO.output(L[no - 1][0], True)
RPi.GPIO.output(L[no - 1][1], True)
RPi.GPIO.output(L[no - 1][2], False)
RPi.GPIO.output(L[no - 1][3], False)
elif (num == 4):
RPi.GPIO.output(L[no - 1][0], False)
RPi.GPIO.output(L[no - 1][1], False)
RPi.GPIO.output(L[no - 1][2], True)
RPi.GPIO.output(L[no - 1][3], False)
elif (num == 5):
RPi.GPIO.output(L[no - 1][0], True)
RPi.GPIO.output(L[no - 1][1], False)
RPi.GPIO.output(L[no - 1][2], True)
RPi.GPIO.output(L[no - 1][3], False)
elif (num == 6):
RPi.GPIO.output(L[no - 1][0], False)
RPi.GPIO.output(L[no - 1][1], True)
RPi.GPIO.output(L[no - 1][2], True)
RPi.GPIO.output(L[no - 1][3], False)
elif (num == 7):
RPi.GPIO.output(L[no - 1][0], True)
RPi.GPIO.output(L[no - 1][1], True)
RPi.GPIO.output(L[no - 1][2], True)
RPi.GPIO.output(L[no - 1][3], False)
elif (num == 8):
RPi.GPIO.output(L[no - 1][0], False)
RPi.GPIO.output(L[no - 1][1], False)
RPi.GPIO.output(L[no - 1][2], False)
RPi.GPIO.output(L[no - 1][3], True)
elif (num == 9):
RPi.GPIO.output(L[no - 1][0], True)
RPi.GPIO.output(L[no - 1][1], False)
RPi.GPIO.output(L[no - 1][2], False)
RPi.GPIO.output(L[no - 1][3], True)
# 防止阴极中毒，每隔一段时间循环点亮所有数字
def protect():
t = 2
for i in range(0, 10):
showDigit(1, i)
showDigit(2, i)
showDigit(3, i)
showDigit(4, i)
time.sleep(t)
t = 0.01
start_time = datetime.datetime.now()
while True:
now_time = datetime.datetime.now()
time.sleep(t)
showDigit(1, int(time.strftime("%H", time.localtime(time.time()))) / 10)
showDigit(2, int(time.strftime("%H", time.localtime(time.time()))) % 10)
showDigit(3, int(time.strftime("%M", time.localtime(time.time()))) / 10)
showDigit(4, int(time.strftime("%M", time.localtime(time.time()))) % 10)
if (now_time - start_time).seconds >= 600:
start_time = datetime.datetime.now()
protect()
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