[RaspberryPi] [python] Inform LINE of room temperature with temperature sensor + IFTTT

environment

• mac
• Raspberry Pi2 Model B
• Raspbian JESSIE -Digital temperature sensor (1wire) DS18B20 +
• python3.5.4

1. Preparation of temperature sensor

Since it uses a 1-wire sensor, add the following to / etc / modules of Raspberry Pi

w1-gpio
w1-therm

Add the following to /boot/config.txt

dtoverlay=w1-gpio-pullup

Sensor connection

--Pin 1 (GND) of the sensor is pin 6 (GND) of Raspberry Pi --Pin 2 (DQ) of the sensor is pin 7 (GPIO4) of Raspberry Pi --Sensor pin 3 (VDD) is Raspberry Pi pin 1 (3.3V)

To The 2nd and 3rd pins of the sensor are connected by a pull-up resistor. Reference: http://blog.livedoor.jp/victory7com/archives/33399310.html

Use the lsmod command to check the connection. If the connection is successful, it will be as follows.

cmd

pi@raspberrypi:~/Documents/work$ lsmod | grep w1
w1_therm                6401  0 
w1_gpio                 4818  0 
wire                   32619  2 w1_gpio,w1_therm

The acquired temperature is written to "/ sys / bus / w1 / devices / 28-XXXXXXXX / w1_slave". (XXXX of 28-XXXXXXXX changes depending on the terminal you are using)

cmd

pi@raspberrypi:~/Documents/work$ cat /sys/bus/w1/devices/28-00000723fabd/w1_slave 
b1 01 4b 46 7f ff 0f 10 8d : crc=8d YES
b1 01 4b 46 7f ff 0f 10 8d t=27062

The current temperature is the value of "t =" divided by 1000.

2. Preparation of IFTTT

Go to IFTTT and create a recipe from My Applet.

Set "this" to "Webhooks" and "that" to "line"

After setting, go to https://ifttt.com/services/maker_webhooks/settings and go to the URL provided to enable the key.

--event is the event name set when setting Webhooks --value is the value you want to send to LINE

By executing the curl command following "You can also try it with curl from a command line.", It will be sent to the set LINE destination.

3. Combine with python

With RaspberryPi, get the temperature with python, request the URL of the Webhooks set with IFTTT, and send the room temperature to LINE.

Install the library to get the temperature

cmd

pip install w1thermsensor

Get and send with the following code

python

from w1thermsensor import W1ThermSensor
import urllib.request, json

sensor = W1ThermSensor(W1ThermSensor.THERM_SENSOR_DS18B20, "(Sensor device name)")
temperature_in_celsius = sensor.get_temperature()

url = "https://maker.ifttt.com/trigger/(Webhooks event name)/with/key/(Webhooks key)"
method = "POST"
headers = {"Content-Type" : "application/json"}

obj = {"value1" : temperature_in_celsius}
json_data = json.dumps(obj).encode("utf-8")

request = urllib.request.Request(url, data=json_data, method=method, headers=headers)
with urllib.request.urlopen(request) as response:
  response_body = response.read().decode("utf-8")

Match THERM_SENSOR_DS18B20 with the model number of the sensor you are using. The device name of the sensor is the XXXX part of 28-XXXXXXXX. After that, if you set this to Coulomb etc., you can get the room temperature regularly.