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本帖最后由 soloforce 于 2013-11-19 17:10 编辑
Cubieboard1的内核已经支持w1温度传感器DS18B20 (依赖的内核选项和模块包括dallas's 1-wire support, gpio_sunxi, w1_sunxi, w1_gpio, w1_slave_therm )。 下图的DIY是在8位8段LED显示模块上同时显示当前时间和气温的实验。
jarry大侠在很久前的帖子(http://forum.cubietech.com/forum.php?mod=viewthread&tid=474)中介绍了DS18B20在cubieboard1上的使用,现在已经不需要打补丁或者另外编译内核模块了。只要按内核配置的说明改好script.bin即可:
本例中的script.fex相关设置如下:
- [gpio_para]
- gpio_used = 1
- gpio_num = 31
- ...
- gpio_pin_28 = port:PB10<0><default><default><0>
- gpio_pin_29 = port:PB11<1><default><default><default>
- gpio_pin_30 = port:PB13<1><default><default><default>
- gpio_pin_31 = port:PH07<1><default><default><default>
- [w1_para]
- gpio = 28
复制代码 最后是本例的C代码
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <time.h>
- #include <signal.h>
- #include <pthread.h>
- #include "gpio_lib.h"
- #define LSBFIRST 0
- #define MSBFIRST 1
- #define DISPBUF_LEN 8
- typedef unsigned char byte;
- // w1-thermal(DS18B20) device file, change it in your case.
- const char* DS18B20_DEVICE="/sys/bus/w1/devices/28-000004f0230d/w1_slave";
- /*
- * 74HC595 relative stuff
- */
- // Cubieboard pin connected to ST_CP of 74HC595 (RCK)
- unsigned int latchPin = SUNXI_GPB(11);
- // Cubieboard pin connected to SH_CP of 74HC595 (SCK)
- unsigned int clockPin = SUNXI_GPB(13);
- // Cubieboard pin connected to DS of 74HC595 (DIN)
- unsigned int dataPin = SUNXI_GPH(7);
- /*
- * Display relative stuff
- */
- // Digits: "0,1,2,....,9" for common anode 8-segment-LED
- unsigned int digit_tab[] = { 0xc0, 0xf9, 0xa4, 0xb0, 0x99, 0x92,
- 0x82, 0xf8, 0x80, 0x90};
- // Digits with a 'dot' at the right-bottom corner
- unsigned int digitdot_tab[] = { 0xc0&0x7f, 0xf9&0x7f, 0xa4&0x7f,
- 0xb0&0x7f, 0x99&0x7f, 0x92&0x7f, 0x82&0x7f,
- 0xf8&0x7f, 0x80&0x7f, 0x90&0x7f};
- // Symbols: 'clear', 'dot', '-'
- unsigned int symbol_tab[]={ 0xff, 0x7f, 0xbf};
- // LED display buffer
- static char dispbuf[DISPBUF_LEN];
- /**
- * Set Cubieboard's GPIO port-D pin I/O mode: INPUT/OUTPUT
- */
- void pinMode(unsigned int pin, unsigned int io_mode)
- {
- if (SETUP_OK != sunxi_gpio_set_cfgpin(pin, io_mode))
- {
- printf("Failed to config GPIO pin\n");
- }
- }
- /**
- * Set Cubieboard's GPIO port-D pin value(LOW/HIGH)
- */
- void digitalWrite(int pin, int hl)
- {
- if (sunxi_gpio_output(pin, hl))
- {
- printf("Failed to set GPIO pin value\n");
- }
- }
- /**
- * Arduino shiftOut:
- * https://github.com/arduino/Arduino/blob/master/hardware/arduino/cores/arduino/wiring_shift.c
- */
- void shiftOut(unsigned int dataPin, unsigned int clockPin, int bitOrder, byte val)
- {
- byte i;
- for (i = 0; i < 8; i++)
- {
- if (bitOrder == LSBFIRST)
- digitalWrite(dataPin, ! !(val & (1 << i)));
- else
- digitalWrite(dataPin, ! !(val & (1 << (7 - i))));
- digitalWrite(clockPin, HIGH);
- digitalWrite(clockPin, LOW);
- }
- }
- /**
- * Initialize the GPIO & relative pins
- */
- void init_gpio()
- {
- if (SETUP_OK != sunxi_gpio_init())
- {
- printf("Failed to initialize GPIO\n");
- }
- pinMode(latchPin, OUTPUT);
- pinMode(clockPin, OUTPUT);
- pinMode(dataPin, OUTPUT);
- }
- /**
- * Get current temperature from the w1-thermal device
- */
- void get_temperature(char* tempbuf, int len)
- {
- FILE* fp=fopen(DS18B20_DEVICE,"r");
- char* line=NULL;
- char* temperature_tok=NULL;
- int temperature=0;
-
- int n;
- if(!fp){
- fprintf(stderr,"Failed to open device(%s) file!\n", DS18B20_DEVICE);
- return;
- }
- // skip the first line
- getline(&line, &n, fp);
- free(line);
- line=NULL;
- // get the temperature line
- getline(&line, &n, fp);
- strtok(line,"=");
- temperature_tok=strtok(NULL,"\n");
-
- strncpy(tempbuf, temperature_tok, len);
- free(line);
- fclose(fp);
- }
- /**
- * Thread of filling the time infomation into display buffer
- */
- void* time_to_dispbuf()
- {
- time_t timep;
- struct tm *p;
- char timebuf[4];
- int interval=1; // in seconds
- while(1){
- // get localtime
- time(&timep);
- p = localtime(&timep);
- sprintf(timebuf, "%02d%02d", p->tm_hour, p->tm_min);
- dispbuf[0]=digit_tab[timebuf[0] - '0'];
- dispbuf[1]=digitdot_tab[timebuf[1] - '0'];
- dispbuf[2]=digit_tab[timebuf[2] - '0'];
- dispbuf[3]=digit_tab[timebuf[3] - '0'];
- dispbuf[4]=symbol_tab[2]; // '-'
- sleep(interval);
- }
- }
- /**
- * Thread of filling the temperature into display buffer
- */
- void* temp_to_dispbuf()
- {
- char tempbuf[3];
- int interval=5; // in seconds;
-
- while(1){
- get_temperature(tempbuf, sizeof tempbuf);
- dispbuf[5]=digit_tab[tempbuf[0]-'0'];
- dispbuf[6]=digitdot_tab[tempbuf[1]-'0'];
- dispbuf[7]=digit_tab[tempbuf[2]-'0'];
-
- sleep(interval);
- }
-
- }
- int main(int argc, char **argv)
- {
- pthread_t get_time_thread, get_temp_thread;
- void * thread_ret;
- init_gpio();
- pthread_create( &get_time_thread, NULL, time_to_dispbuf, NULL);
- pthread_create( &get_temp_thread, NULL, temp_to_dispbuf, NULL);
-
- while (1)
- {
- int i;
- for(i=0;i<DISPBUF_LEN;i++){
- digitalWrite(latchPin, 0);
- shiftOut(dataPin, clockPin, MSBFIRST, 1<<i);
- shiftOut(dataPin, clockPin, MSBFIRST, dispbuf[i]);
- digitalWrite(latchPin, 1);
- usleep(2000);
- }
-
- }
- pthread_join(get_time_thread,&thread_ret);
- pthread_join(get_temp_thread,&thread_ret);
- return 0;
- }
复制代码 |
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