https://github.com/andy-y-li/pi-temp
Get the temperature of Raspberry Pi and control the fan, write the process data to sqlite database.
https://github.com/andy-y-li/pi-temp
auto-start db fan pi3 raspiberry sqlite temperature
Last synced: 7 months ago
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Get the temperature of Raspberry Pi and control the fan, write the process data to sqlite database.
- Host: GitHub
- URL: https://github.com/andy-y-li/pi-temp
- Owner: andy-y-li
- License: gpl-3.0
- Created: 2020-04-22T06:34:12.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2020-04-22T06:42:56.000Z (over 5 years ago)
- Last Synced: 2025-01-23T01:22:56.839Z (9 months ago)
- Topics: auto-start, db, fan, pi3, raspiberry, sqlite, temperature
- Language: Python
- Size: 215 KB
- Stars: 2
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
## RPi temperature & fan control
本文使用python实现对树莓派的温度实时检测和风扇的控制，并把相关的温度，风扇控制信息保存到sqlite数据库中。
1. ***创建数据库和空表***
a. 在文件 ***create-table-only.sql***定义一个表temps, 共4个字段: 其中 ***name***, ***tdatetime***有默认值,
***temperature*** 记录当前温度, ***fan*** 记录风扇的使用率；
```
PRAGMA foreign_keys=OFF;
BEGIN TRANSACTION;
CREATE TABLE temps(
name DEFAULT 'RPi.CPU',
tdatetime DATETIME DEFAULT (datetime('now', 'localtime')),
temperature NUMERIC NOT NULL,
fan NUMERIC NOT NULL
);
COMMIT;
```
b. 写一个shell脚本 ***create-table-only.sh***, 用于创建一个空表：
```
#!/bin/sh
DBNAME="cpu.db"
rm -f $DBNAME
echo 开始插入数据
sqlite3 $DBNAME < create-table-only.sql
echo 插入完成
```
给shell文件新增可执行权限, 运行后生成数据库文件 ***cpu.db***：
```
chmod +x create-table-only.sh
./create-table-only.sh
```
2. ***用python读取温度,控制风扇，并保存到数据库***
创建文件 ***db-insert-temp.py***
```
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import time
import sqlite3
import RPi.GPIO as GPIO
T_HIGH = 50
T_LOW = 45
fan_pin = 36
def get_cpu_temp():
# 打开文件
file = open("/sys/class/thermal/thermal_zone0/temp")
# 读取结果，并转换为浮点数
temp = float(file.read()) / 1000
# 关闭文件
file.close()
return temp
def insert_cpu_temp(temp, open_fan_num, close_fan_num):
# 连接数据库
conn=sqlite3.connect('cpu.db')
curs=conn.cursor()
f = float(open_fan_num)/float((open_fan_num + close_fan_num)) * 100
fans = "%.1f%%" % (f)
# 插入数据库
strtemp = "%.1f" % (temp);
curs.execute("INSERT INTO temps(temperature, fan) VALUES((?),(?))", (strtemp, fans))
conn.commit()
# 关闭数据库
conn.close()
def init_gpio():
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BOARD)
GPIO.setup(fan_pin, GPIO.OUT)
# Close Fan
GPIO.output(fan_pin, GPIO.LOW)
def process_fan(temp):
if temp > T_HIGH:
GPIO.output(fan_pin, GPIO.HIGH)
return 1
elif temp < T_LOW:
GPIO.output(fan_pin, GPIO.LOW)
return 2
return 0
def main():
init_gpio()
n_loop = 0
case_open_fan_num = 0
case_close_fan_num = 0
fan_is_on = False
temp = get_cpu_temp()
insert_cpu_temp(temp, 0, 1)
temp_sum = 0.0
while True:
temp = get_cpu_temp()
temp_sum += temp;
time.sleep(5)
ret = process_fan(temp)
if ret == 1:
case_open_fan_num += 1;
fan_is_on = True
elif ret == 2:
case_close_fan_num += 1;
fan_is_on = False
else:
if fan_is_on == True:
case_open_fan_num += 1
else:
case_close_fan_num += 1
n_loop += 1
if n_loop >= 60:
temp = temp_sum / n_loop;
insert_cpu_temp(temp, case_open_fan_num, case_close_fan_num)
n_loop = 0
temp_sum = 0.0
case_open_fan_num = 0
case_close_fan_num = 0
if __name__ == '__main__':
main()
```
***简要说明***
a. 从文件 ***/sys/class/thermal/thermal_zone0/temp*** 读取树莓派的当前温度，
也可以用命令 ***/opt/vc/bin/vcgencmd measure_temp***得到树莓派的温度；
b. 风扇控制, 树莓派的GPIO分布如下:
风扇的控制电路如下：
***说明:*** 按BOARD引脚编码, +5V为4脚，GND接到6脚，用36脚控制NPN开关：
```
fan_pin = 36
def init_gpio():
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BOARD)
GPIO.setup(fan_pin, GPIO.OUT)
# Close Fan
GPIO.output(fan_pin, GPIO.LOW)
```
在这里，温度超过50度时打开风扇，小于45度时关闭风扇：
```
T_HIGH = 50
T_LOW = 45
def process_fan(temp):
if temp > T_HIGH:
GPIO.output(fan_pin, GPIO.HIGH)
return 1
elif temp < T_LOW:
GPIO.output(fan_pin, GPIO.LOW)
return 2
return 0
```
C. 在程序中，加入了温度和风扇使用率的统计，并写数据库：
```
.
.
.
temp_sum = 0.0
while True:
temp = get_cpu_temp()
temp_sum += temp;
time.sleep(5)
ret = process_fan(temp)
if ret == 1:
case_open_fan_num += 1;
fan_is_on = True
elif ret == 2:
case_close_fan_num += 1;
fan_is_on = False
else:
if fan_is_on == True:
case_open_fan_num += 1
else:
case_close_fan_num += 1
n_loop += 1
if n_loop >= 60:
temp = temp_sum / n_loop;
insert_cpu_temp(temp, case_open_fan_num, case_close_fan_num)
n_loop = 0
temp_sum = 0.0
case_open_fan_num = 0
case_close_fan_num = 0
```
运行时查看数据结果：
```
sqlite3 cpu.db
再输入 SELECT * FROM temps;
2020-04-22T10:03:14Z,47.4,63.3%
2020-04-22T10:08:15Z,48.1,35.0%
2020-04-22T10:13:15Z,46.2,43.3%
2020-04-22T10:18:15Z,47 ,71.7%
2020-04-22T10:23:16Z,47.9,36.7%
```
3. ***设置开机启动***
a. 启动脚本 ***auto-start.sh***
```
#!/bin/bash
cd /home/pi/work/py/temp
python db-insert-temp.py &
```
用shell脚本来启动python文件, 注意要为auto-start.sh 增加可执行权限：
```
chmod +x auto-start.sh
```
b. 设置启动项, 在/etc/init.d 下编辑文件temp-app
```
sudo vim /etc/init.d/temp-app
```
内容如下：
```
#!/bin/sh
#/etc/init.d/init-app
### BEGIN INIT INFO
# Provides: get-ip-address
# Required-Start: $remote_fs $syslog
# Required-Stop: $remote_fs $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: init-app
# Description: This service is used to start init shell
### END INIT INFO
case "$1" in
start)
echo "Starting temp service"
su pi -c "exec /home/pi/work/py/temp/auto-start.sh"
;;
stop)
echo "Stop"
;;
*)
echo "Usage: service temp-app start|stop"
exit 1
;;
esac
exit 0
```
保存后，设置开机启动：
```
sudo update-rc.d temp-app defaults
```
重启树莓派就可以自动启动程序了, 也可以先手动启动:
```
sudo service temp-app start
```