Cubieboard1 displays the DS18B20 temperature information to the LED

The kernel of cubieboard1 already supports W1 temperature sensor DS18B20 (dependent kernel options and modules include Dallas's 1-wire support, gpio_sunxi, ww.sunxi, ww.gpio, ww.slave_therm ). DIY is an experiment that displays the current time and temperature at the same time on the 8-bit 8-segment LED display module.

Jarry's post long ago (http://forum.cubietech.com/forum.php? MoD = viewthread & tid = 474) describes the use of DS18B20 on cubieboard1, and does not need to be patched or compiled separately. You only need to modify script. Bin according to the Kernel configuration instructions:

In this example, the script. Fex settings are as follows:

• 
  

• [Gpio_para]

• Gpio_used = 1

• Gpio_num = 31

• ...

• Gpio_pin_28 = port: pb10 <0> <default> <0>
  

• Gpio_pin_29 = port: pb11 <1> <default>
  

• Gpio_pin_30 = port: pb13 <1> <default>
  

• Gpio_pin_31 = port: ph07 <1> <default>

• 
  

• [W1_para]

• Gpio = 28

• 
  

• 
  

[Color = RGB (46,166,255 )! Important] copy the code
Finally, the C code of this example

• 
  

• # 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/ww.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/Ardui... uino/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 ))));

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• 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 b20_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 b20_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 );

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• 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 );

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• 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);

• Digitalwrite (latchpin, 1 );

• Usleep (2000 );

• }

• 
  

• }

• 
  

• Pthread_join (get_time_thread, & thread_ret );

• Pthread_join (get_temp_thread, & thread_ret );

• Return 0;

• }

• 
  

Original article soloforce
Http://forum.cubietech.com/forum... 1545 & extra = Page % 3d1