Raspberry Pi 3 + USB温度計でグラフ化 AWS IoT Core その②

バックナンバー

Amazonからてんぱーちゃんが届く

TEMPerで気温を測ろう

$ lsusb

Bus 001 Device 004: ID 413d:2107
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp. SMC9514 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

不幸にも

ID 413d:2107

この番号が出ると険しいコース

$ sudo apt-get install build-essential libudev-dev libusb-*
$ sudo apt install libusb-1.0-0-dev libudev-dev libfox-1.6-dev
$ sudo apt-get install autotools-dev autoconf automake libtool cmake

git clone https://github.com/signal11/hidapi
cd hidapi/linux
make -f Makefile-manual
sudo cp libhidapi-hidraw.so /usr/local/lib/
sudo ln -s /usr/local/lib/libhidapi-hidraw.so /usr/local/lib/libhidapi-hidraw.so.0

cd
git clone https://github.com/hughesr/TEMPered
cd TEMPered/
sudo git checkout hack-413d-2107
sudo git reset --hard 75aa1e2
sudo cmake .
sudo make
sudo make install
sudo ldconfig

$ sudo tempered

/dev/hidraw1 0: temperature 30.93 °C
/dev/hidraw1 1: Failed to get the temperature: Not enough data was read from the sensor.
/dev/hidraw1 1: no sensor data available

30.93 °C ??

$ sudo tempered 2> /dev/null | awk 'NR==1' | cut -b 17-
temperature 32.43 °C

ほわー？32.43 °C ??

秋なのだが。。おかしい。

USBタップを導入する

$ sudo tempered 2> /dev/null | awk 'NR==1' | cut -b 17-

temperature 26.37 °C

まともな値が出た。

数値だけにする

$ sudo tempered 2> /dev/null | awk 'NR==1' | cut -b 29-33
26.56

Pythonでスクリプトを書く

$ cat getTemper.py


import subprocess

from subprocess import check_output
out = check_output("sudo tempered 2> /dev/null | awk 'NR==1' | cut -b 29-33", shell=True)
print(out)

実行