所以我被招募到我学校的Baja赛车队，在那里我们设计建造并与越野沙滩车型车竞争。我是CS专业，对python有相当多的经验，因此被要求帮助电气团队与我们想要的所有传感器接口。到目前为止一直很好，但现在我正在使用红外温度传感器读取环境温度和物体温度。 （我们将把它放在发动机的某处，以读取它的温度并输出到我们的GUI）
问题是，似乎使用过这个传感器的唯一库都是用C语言编写的，并且通常与arduinos一起使用......尽管如此，我编译并编辑了一些我在网上发现的C代码并且效果很好！在C. :(因为我们的项目完全基于python;我真的很喜欢通过i2c和Python阅读这个传感器的一些帮助，虽然我真的不具备编写库的经验，特别是对于电子产品。任何提示都会很好地引导我走向正确的方向。这是我们目前正在使用的C代码，我基本上希望在Python中使用相同的东西：
//fordit: gcc MLXi2c.c -o i2c -l bcm2835
#include <stdio.h>
#include <bcm2835.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include<time.h>
#define AVG 1 //averaging samples
#define LOGTIME 10 //loging period
int main(int argc, char **argv)
{
unsigned char buf[6];
unsigned char i,reg;
double temp=0,calc=0, skytemp,atemp;
FILE *flog;
flog=fopen("mlxlog.csv", "a");..
bcm2835_init();
bcm2835_i2c_begin();
bcm2835_i2c_set_baudrate(25000);.
// set address...........................................................................................
bcm2835_i2c_setSlaveAddress(0x5a);
....
printf("\nOk, your device is working!!\n");
....
....
while(1) {
time_t t = time(NULL);
<------>struct tm tm = *localtime(&t);
<------>calc=0;
<------>reg=7;
<------>for(i=0;i<AVG;i++){
<------> bcm2835_i2c_begin();
<------> bcm2835_i2c_write (®, 1);
<------> bcm2835_i2c_read_register_rs(®,&buf[0],3);
<------> temp = (double) (((buf[1]) << 8) + buf[0]);
<------> temp = (temp * 0.02)-0.01;
<--> temp = temp - 273.15;
<------> calc+=temp;
<------> sleep(1);
<------> }
<------>skytemp=calc/AVG;
<------>calc=0;
<------>reg=6;
<------>for(i=0;i<AVG;i++){
<------> bcm2835_i2c_begin();
<------> bcm2835_i2c_write (®, 1);
<------> bcm2835_i2c_read_register_rs(®,&buf[0],3);
<------> temp = (double) (((buf[1]) << 8) + buf[0]);
<------> temp = (temp * 0.02)-0.01;
<--> temp = temp - 273.15;
<------> calc+=temp;
<------> sleep(1);
<------> }
<------>atemp=calc/AVG;
<------>printf("%02d-%02d %02d:%02d:%02d\n Tambi=%04.2f C, Tobj=%04.2f C\n", tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,atemp,skytemp);
<------>fprintf(flog,"%04d-%02d-%02d %02d:%02d:%02d,%04.2f,%04.02f\n",tm.tm_year+1900, tm.tm_mon +1, tm.tm_mday,tm.tm_hour, tm.tm_min, tm.tm_sec,atemp,skytemp);
<------>fflush(flog);
<------>sleep(LOGTIME-(2*AVG));
}
...
printf("[done]\n");
}
提前感谢！
答案 0 :(得分：1)
<强>的变化：
while(1) - 每次执行只读取一次。如果传感器需要重复启动，则可能需要for / while循环;除非你打算从python中删除进程，否则不要让它成为无限循环。printf现在输出一个由起始和结束管道分隔的JSON字符串/ | return 0;添加到main()，以便python的子进程模块知道
怎么了将其另存为 mlx90614_query.c 并编译：
//fordit: gcc mlx90614_query.c -o mlx90614_query -l bcm2835
#include <stdio.h>
#include <bcm2835.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <time.h>
#define AVG 1 //averaging samples
#define LOGTIME 10 //loging period
int main(int argc, char **argv)
{
unsigned char buf[6];
unsigned char i,reg;
double temp=0,calc=0, skytemp,atemp;
FILE *flog;
flog=fopen("mlxlog.csv", "a");
bcm2835_init();
bcm2835_i2c_begin();
bcm2835_i2c_set_baudrate(25000);
// set address
bcm2835_i2c_setSlaveAddress(0x5a);
printf("\nOk, your device is working!!\n");
time_t t = time(NULL);
struct tm tm = *localtime(&t);
calc=0;
reg=7;
for(i=0;i<AVG;i++){
bcm2835_i2c_begin();
bcm2835_i2c_write (®, 1);
bcm2835_i2c_read_register_rs(®,&buf[0],3);
temp = (double) (((buf[1]) << 8) + buf[0]);
temp = (temp * 0.02)-0.01;
temp = temp - 273.15;
calc+=temp;
sleep(1);
}
skytemp=calc/AVG;
calc=0;
reg=6;
for(i=0;i<AVG;i++){
bcm2835_i2c_begin();
bcm2835_i2c_write (®, 1);
bcm2835_i2c_read_register_rs(®,&buf[0],3);
temp = (double) (((buf[1]) << 8) + buf[0]);
temp = (temp * 0.02)-0.01;
temp = temp - 273.15;
calc+=temp;
sleep(1);
}
atemp=calc/AVG;
printf("|{\"time\":{\"month\":\"%02d\",\"day\":\"%02d\",\"hour\":\"%02d\",\"min\":\"%02d\",\"sec\":\"%02d\"},\"data\":{\"t_ambi\":\"%04.2f\",\"t_obj\":\"%04.2f\"}}|\n", tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,atemp,skytemp);
fprintf(flog,"%04d-%02d-%02d %02d:%02d:%02d,%04.2f,%04.02f\n",tm.tm_year+1900, tm.tm_mon +1, tm.tm_mday,tm.tm_hour, tm.tm_min, tm.tm_sec,atemp,skytemp);
fflush(flog);
sleep(LOGTIME-(2*AVG));
printf("[done]\n");
return 0;
}
您的C程序现在输出您现有的调试消息以及此json（“|”用作分隔符）：
{
"time": {
"month": "03",
"day": "09",
"hour": "20",
"min": "24",
"sec": "28"
},
"data": {
"t_ambi": "77.77",
"t_obj": "34.44"
}
}
将此保存为与mlx90614_query相同的文件夹中的python脚本（如果复制/粘贴到交互式解释器，额外的空格将导致麻烦）：
from __future__ import print_function
import json
import subprocess
import sys
sensor_dict = {}
py3 = False
# python version check determines string handling
try:
if (sys.version_info > (3, 0)):
py3 = True
except:
pass
try:
subp_ret = subprocess.check_output(["./mlx90614_query"])
# at this point, subprocess succeeded and subp_ret holds your output
if py3:
subp_ret = subp_ret.decode('utf8')
sensor_dict = json.loads(subp_ret.split("|")[1].strip())
# cast temperatures to float and print
for k in sensor_dict["data"]:
val = float(sensor_dict["data"][k])
sensor_dict["data"][k] = val
print (k, "\t", val)
# cast date/time segments to int and print
for k in sensor_dict["time"]:
val = int(sensor_dict["time"][k])
sensor_dict["time"][k] = val
print (k, "\t", val)
# Now go win that race! :P
except Exception as e:
print(str(e))
输出：
$ gcc mlx90614_query.c -o mlx90614_query -l bcm2835
$
$ ./mlx90614_query
Ok, your device is working!!
|{"time":{"month":"03","day":"09","hour":"21","min":"45","sec":"53"},"data":{"t_ambi":"0.00","t_obj":"0.00"}}|
[done]
$ python3.4 mlx_print.py
t_obj 34.44
t_ambi 77.77
hour 21
sec 33
min 58
month 3
day 9
$ python2 mlx_print.py
t_ambi 77.77
t_obj 34.44
min 58
sec 37
day 9
hour 21
month 3
很抱歉您偷了作业 - 只需<3代码：D