From 38bdcfe45ea89f6e94b902425e89858c86689b45 Mon Sep 17 00:00:00 2001
From: guowenxue <guowenxue@gmail.com>
Date: Fri, 31 Aug 2018 18:30:57 +0800
Subject: [PATCH] add ds18b20 python and C source code
---
program/ds18b20/ds18b20.c | 93 +++++++++++++++++++++++++++++++
program/ds18b20/ds18b20.py | 37 ++++++++++++
2 files changed, 130 insertions(+), 0 deletions(-)
diff --git a/program/ds18b20/ds18b20.c b/program/ds18b20/ds18b20.c
new file mode 100644
index 0000000..c04d69b
--- /dev/null
+++ b/program/ds18b20/ds18b20.c
@@ -0,0 +1,93 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <string.h>
+#include <time.h>
+#include <errno.h>
+
+int ds18b20_get_temperature(float *temp);
+
+
+int main(int argc, char *argv[])
+{
+ float temp;
+
+ if( ds18b20_get_temperature(&temp) < 0 )
+ {
+ printf("ERROR: ds18b20 get temprature failure\n");
+ return 1;
+ }
+
+ printf("DS19B20 get temperature: %f ℃\n", temp);
+ return 0;
+}
+
+int ds18b20_get_temperature(float *temp)
+{
+ char w1_path[50] = "/sys/bus/w1/devices/";
+ char chip[20];
+ char buf[128];
+ DIR *dirp;
+ struct dirent *direntp;
+ int fd =-1;
+ char *ptr;
+ float value;
+ int found = 0;
+
+ if( !temp )
+ {
+ return -1;
+ }
+
+ if((dirp = opendir(w1_path)) == NULL)
+ {
+ printf("opendir error: %s\n", strerror(errno));
+ return -2;
+ }
+
+ while((direntp = readdir(dirp)) != NULL)
+ {
+ if(strstr(direntp->d_name,"28-"))
+ {
+ strcpy(chip,direntp->d_name);
+ found = 1;
+ }
+ }
+ closedir(dirp);
+
+ if( !found )
+ {
+ printf("Can not find ds18b20 in %s\n", w1_path);
+ return -3;
+ }
+
+ strncat(w1_path, chip, sizeof(w1_path));
+ strncat(w1_path, "/w1_slave", sizeof(w1_path));
+
+ if( (fd=open(w1_path, O_RDONLY)) < 0 )
+ {
+ printf("open %s error: %s\n", w1_path, strerror(errno));
+ return -4;
+ }
+
+ if(read(fd, buf, sizeof(buf)) < 0)
+ {
+ printf("read %s error: %s\n", w1_path, strerror(errno));
+ return -5;
+ }
+
+ ptr = strstr(buf, "t=")+2;
+
+ if( !ptr )
+ {
+ printf("ERROR: Can not get temperature\n");
+ return -6;
+ }
+
+ *temp = atof(ptr)/1000;
+
+ return 0;
+}
+
diff --git a/program/ds18b20/ds18b20.py b/program/ds18b20/ds18b20.py
new file mode 100644
index 0000000..31f1f8b
--- /dev/null
+++ b/program/ds18b20/ds18b20.py
@@ -0,0 +1,37 @@
+#!/usr/bin/python
+#-*- coding:utf-8 -*-
+
+import glob
+import time
+
+base_dir = '/sys/bus/w1/devices/'
+device_folder = glob.glob(base_dir + '28*')[0]
+device_file = device_folder + '/w1_slave'
+
+def read_rom():
+ name_file=device_folder+'/name'
+ f = open(name_file,'r')
+ return f.readline()
+
+def read_temp_raw():
+ f = open(device_file, 'r')
+ lines = f.readlines()
+ f.close()
+ return lines
+
+def read_temp():
+ lines = read_temp_raw()
+ while lines[0].strip()[-3:] != 'YES':
+ time.sleep(0.2)
+ lines = read_temp_raw()
+
+ equals_pos = lines[1].find('t=')
+ if equals_pos != -1:
+ temp_string = lines[1][equals_pos+2:]
+ temp_c = float(temp_string) / 1000.0
+ return temp_c
+
+
+
+print(' DS19B20 get temperature: %3.3f ℃'% read_temp())
+
--
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