Go to Qiita Advent Calendar 2024 Top
LoginSignup
3
1

Delete article

Deleted articles cannot be recovered.

Draft of this article would be also deleted.

Are you sure you want to delete this article?

More than 3 years have passed since last update.

@mashi0727

Raspberry Piでsystemdを使って温度と湿度を記録する

Last updated at Posted at 2020-04-10

やりたいこと

Raspi4の起動時に室温と湿度をひたすら記録する

必要なもの

H/W

使用したH/Wは以下のとおり

  1. Raspberry Pi 4
  2. HDC1000

S/W

  1. Python 3.6.1 | packaged by rpi | (default, Apr 20 2017, 19:35:19)
  2. Linux raspi4 4.19.97-v7l+ #1294 SMP Thu Jan 30 13:21:14 GMT 2020 armv7l GNU/Linux

各種設定

HDC1000の接続

スクリーンショット 2020-04-10 13.11.17.png

ラズパイ4のパーツを見つけられませんでした。

HDC1000の設定

/boot/config.txt

i2c関連の設定部分

dtparam=i2c_arm=on

/etc/modules

モジュール関連の設定

i2c-dev
i2c-bcm2835

HDC1000の設定の確認

sh
$ lsmod | grep i2c
i2c_bcm2835            16384  0
i2c_dev                20480  0
sh
$ dmesg | grep i2c
[    2.153160] i2c /dev entries driver
sh
$ i2cdetect -l
i2c-1	i2c       	bcm2835 I2C adapter             	I2C adapter

$ i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: 40 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

動作確認

サンプルプログラムです。

python
# -*- coding: utf-8 -*-
import smbus
import time

# Get I2C bus
bus = smbus.SMBus(1)

# HDC1000 address, 0x40(64)
# Select configuration register, 0x02(02)
#        0x30(48)    Temperature, Humidity enabled, Resolultion = 14-bits, Heater on
bus.write_byte_data(0x40, 0x02, 0x30)

# HDC1000 address, 0x40(64)
# Send temp measurement command, 0x00(00)
bus.write_byte(0x40, 0x00)

time.sleep(0.2)

# HDC1000 address, 0x40(64)
# Read data back, 2 bytes
# temp MSB, temp LSB
data0 = bus.read_byte(0x40)
data1 = bus.read_byte(0x40)

# Convert the data
temp = (data0 * 256.000) + data1
cTemp = (temp / 65536.000) * 165.000 - 40.000

# HDC1000 address, 0x40(64)
# Send humidity measurement command, 0x01(01)
bus.write_byte(0x40, 0x01)
time.sleep(0.2)

# HDC1000 address, 0x40(64)
# Read data back, 2 bytes
# humidity MSB, humidity LSB
data0 = bus.read_byte(0x40)
data1 = bus.read_byte(0x40)


# Convert the data
humidity = (data0 * 256.000) + data1
humidity = (humidity / 65536.000) * 100.000

print('Humid.:' + str(humidity) + '％')
print('Temp. :' + str(cTemp) + '℃ ')

実行すると以下のようになります。


$ python HDC1000.py
Humid.:41.96014404296875％
Temp. :22.763748168945312℃

記録用プログラム

記録用のプログラムは、こんな感じにしました。

python
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import smbus
import time
import datetime
import csv
import pathlib
import os

file_name = 'th_data.csv'
header_data = 'date_time,temperature\n'

def read_temp():
        # Get I2C bus
        bus = smbus.SMBus(1)
        # HDC1000 address, 0x40(64)
        # Select configuration register, 0x02(02)
        #        0x30(48)    Temperature, Humidity enabled, Resolultion = 14-bits, Heater on
        bus.write_byte_data(0x40, 0x02, 0x30)

        # HDC1000 address, 0x40(64)
        # Send temp measurement command, 0x00(00)
        bus.write_byte(0x40, 0x00)
        time.sleep(0.2)

        # HDC1000 address, 0x40(64)
        # Read data back, 2 bytes
        # temp MSB, temp LSB
        data0 = bus.read_byte(0x40)
        data1 = bus.read_byte(0x40)

        # Convert the data
        temp = (data0 * 256.000) + data1
        cTemp = (temp / 65536.000) * 165.000 - 40.000
        return cTemp

def read_humid():
        # Get I2C bus
        bus = smbus.SMBus(1)
        # HDC1000 address, 0x40(64)
        # Select configuration register, 0x02(02)
        #        0x30(48)    Temperature, Humidity enabled, Resolultion = 14-bits, Heater on
        bus.write_byte_data(0x40, 0x02, 0x30)

        # HDC1000 address, 0x40(64)
        # Send humidity measurement command, 0x01(01)
        bus.write_byte(0x40, 0x01)
        time.sleep(0.2)

        # HDC1000 address, 0x40(64)
        # Read data back, 2 bytes
        # humidity MSB, humidity LSB
        data0 = bus.read_byte(0x40)
        data1 = bus.read_byte(0x40)

        # Convert the data
        humidity = (data0 * 256.000) + data1
        humidity = (humidity / 65536.000) * 100.000
        return humidity


def file_check():
        global file_name
        file_name = pathlib.Path(file_name)
        if os.path.exists(file_name):
                print('Data File exists!')
        else:
                file_name.touch()
def header():
        global file_name
        with open(file_name) as f:
                line = f.readline()
        if 'date' in line:
                print('Header exists!')
        else:
                with open(file_name) as f:
                        lines = f.readlines()
                        lines.insert(0, header_data)
                        f.close()
                with open(file_name, mode='w') as f:
                        f.writelines(lines)

def main():
        global file_name
        file_check()
        header()
        while True:
                now = datetime.datetime.now()
                temp = read_temp()
                humid = read_humid()
#               print(now.strftime('%Y%m%d-%H:%M:%S'), '{:.3f}'.format(temp), '{:.3f}'.format(humid))
                save_data = [now.strftime('%Y%m%d-%H:%M:%S'), '{:.3f}'.format(temp), '{:.3f}'.format(humid)]
                with open(file_name,'a',newline='') as f:
                        writer = csv.writer(f, lineterminator='\r\n')
                        writer.writerow(save_data)
                time.sleep(10)

if __name__ == '__main__':
        main()

systemdの設定と自動起動の設定

/etc/systemd/system/thlogger.service

thloggerというサービス名にしました。

[Unit]
Description=TH_Logger
After=syslog.target

[Service]
User = pi
PIDFile=/var/run/thlogger.pid
WorkingDirectory=/home/pi/Jupyter/data
ExecStart=/home/pi/berryconda3/bin/python /home/pi/works/HDC1000/TH_logger.py
ExecStop=/bin/kill $MAINPID
ExecReload=/bin/kill -HUP $MAINPID
Restart=always

RestartSec=10s
[Install]
WantedBy = multi-user.target

$ sudo systemctl daemon-reload
$ sudo systemctl start thlogger

起動ログを確認（/var/log/system）し

$ sudo systemctl status thlogger.service -l
● thlogger.service - TH_Logger
   Loaded: loaded (/etc/systemd/system/thlogger.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2020-04-10 13:09:16 JST; 18min ago
 Main PID: 352 (python)
    Tasks: 1 (limit: 4915)
   Memory: 9.1M
   CGroup: /system.slice/thlogger.service
           └─352 /home/pi/berryconda3/bin/python /home/pi/works/HDC1000/TH_logger.py

 4月 10 13:09:16 raspi4 systemd[1]: Started TH_Logger.

問題なければ、起動時に実行するようにします。

$ sudo systemctl enable thlogger

自動起動しないようにする

サービスの状況の確認

$ sudo systemctl status thplogger.service
● thplogger.service - THP_Logger
   Loaded: loaded (/etc/systemd/system/thplogger.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2021-01-29 16:57:13 JST; 4s ago
 Main PID: 7244 (python)
    Tasks: 1 (limit: 4248)
   CGroup: /system.slice/thplogger.service
           └─7244 /usr/bin/python /home/pi/share/pi4_works/thp_logger/THP_logger.py

 1月 29 16:57:13 raspi4 systemd[1]: Started THP_Logger.

稼働していることを確認して、サービスを停止します。

$ sudo systemctl status thplogger.service
● thplogger.service - THP_Logger
   Loaded: loaded (/etc/systemd/system/thplogger.service; enabled; vendor preset: enabled)
   Active: inactive (dead) since Fri 2021-01-29 16:58:42 JST; 1s ago
  Process: 7244 ExecStart=/usr/bin/python /home/pi/share/pi4_works/thp_logger/THP_logger.py (code=killed, signal=TERM)
  Process: 7339 ExecStop=/bin/kill $MAINPID (code=exited, status=0/SUCCESS)
 Main PID: 7244 (code=killed, signal=TERM)

 1月 29 16:57:13 raspi4 systemd[1]: Started THP_Logger.
 1月 29 16:58:42 raspi4 systemd[1]: Stopping THP_Logger...
 1月 29 16:58:42 raspi4 systemd[1]: thplogger.service: Main process exited, code=killed, status=15/TERM
 1月 29 16:58:42 raspi4 systemd[1]: thplogger.service: Succeeded.
 1月 29 16:58:42 raspi4 systemd[1]: Stopped THP_Logger.

自動起動しないようにします。

$ sudo systemctl disable thplogger.service
Removed /etc/systemd/system/multi-user.target.wants/thplogger.service.
3
1
0

Register as a new user and use Qiita more conveniently

  1. You get articles that match your needs
  2. You can efficiently read back useful information
  3. You can use dark theme
What you can do with signing up
Sign upLogin
3
1

Delete article

Deleted articles cannot be recovered.

Draft of this article would be also deleted.

Are you sure you want to delete this article?