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https://github.com/ptr33/temp_humidity_sensor
Temperature and Humidity Sensor with a DHT22 and Raspberry Pi Zero W and publish to MQTT
https://github.com/ptr33/temp_humidity_sensor
dht22 homeassistant humidity-sensor mqtt raspberry-pi-zero-w rasperry-pi temperature-sensor
Last synced: 15 days ago
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Temperature and Humidity Sensor with a DHT22 and Raspberry Pi Zero W and publish to MQTT
- Host: GitHub
- URL: https://github.com/ptr33/temp_humidity_sensor
- Owner: ptr33
- License: mit
- Created: 2024-11-07T12:08:39.000Z (3 months ago)
- Default Branch: main
- Last Pushed: 2024-11-17T15:38:47.000Z (3 months ago)
- Last Synced: 2024-11-17T16:37:19.387Z (3 months ago)
- Topics: dht22, homeassistant, humidity-sensor, mqtt, raspberry-pi-zero-w, rasperry-pi, temperature-sensor
- Language: Shell
- Homepage:
- Size: 2.38 MB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Temperature and Humidty Sensor
This project uses a DHT22 sensor connected to a Raspberry Pi Zero W to capture temperature and humidity measurements. The information is published over WLAN to a [MQTT](https://mqtt.org/) broker and displayed in [Homeassistant](https://www.home-assistant.io/).
The configuration of this MQTT client and topics should be set in [config.json](https://github.com/ptr33/temp_humidity_sensor/blob/main/config.json). A MQTT broker should already be running - example in https://mosquitto.org/
## References
Initial work from
- https://github.com/adafruit/Adafruit-Raspberry-Pi-Python-Code/tree/legacy/Adafruit_DHT_Driver
- https://www.airspayce.com/mikem/bcm2835/
## Raspberry PI Zero W setup
Create an image with [Raspberry PI Imaging Utility](https://www.raspberrypi.com/news/raspberry-pi-imager-imaging-utility/).
Setup hostname, wifi access, username, password and locale.
Connect Raspberry to DHT22 sensor ([reference](https://github.com/FranzTscharf/Python-DHT22-Temperature-Humidity-Sensor-Raspberry-Pi)):
GPIO pins:
### Install Tool
On the Raspberr Pi Zero W execute the following comands:
```bash
git clone https://github.com/ptr33/temp_humidity_sensor.git
cd temp_humidity_sensor/
pip install -r requirements.txt --break-system-packages
git update-index --assume-unchanged config.json
```
Then edit server settings, topics and hardware configuration in [config.json](https://github.com/ptr33/temp_humidity_sensor/blob/main/config.json)
To run the script use:
```bash
./getreading.py
```
### Crontab
To execute the script every 10 minutes, use crontab:
```bash
crontab -e
# add below lines to crontab, if you use nano, use ^O^X to install
# run every 10 minutes
*/10 * * * * cd ~/temp_humidity_sensor/ && ./getreading.py
```
### Compile Adafruid_DHT binary (optional)
```bash
cd ~/temp_humidity_sensor/bcm2835_lib/bcm2835-1.75
./configure
make
sudo make install
cd ../../Adafruit_DHT_Driver
make
make test
make clean
```
The library was tested on a Raspbery Pi Zero W (first version) -
if you want to use the driver on a different device, you might need to modify [LOW_HIGH_THRESHOLD](https://github.com/ptr33/temp_humidity_sensor/blob/dev/Adafruit_DHT_Driver/Adafruit_DHT.c#L31)
#### Test
```bash
cd ~/temp_humidity_sensor/Adafruit_DHT_Driver
sudo ./Adafruit_DHT 22 4
```
The output should be:
```
ptr@raspberrypi:~/temp_humidity_sensor/Adafruit_DHT_Driver $ sudo ./Adafruit_DHT 22 4
Using pin #4
Data (40): 0x2 0x17 0x0 0xe1 0xfa
Temp = 22.5 *C, Hum = 53.5 %
```
## Integrate with Homeassistant
Create a MQTT client in [Homeassistant](https://www.home-assistant.io/) for the same MQTT server as used for publishing (configured config.json). Then edit the following files:
*configuration.yaml*
```yaml
mqtt: !include mqtt.yaml
```
*mqtt.yaml*
```yaml
sensor:
- name: "Temperature"
state_topic: "stat/room/temperature"
state_class: measurement
unit_of_measurement: "°C"
device_class: temperature
- name: "Humidity"
state_topic: "stat/room/humidity"
state_class: measurement
unit_of_measurement: "%"
device_class: moisture
- name: "Dewpoint"
state_topic: "stat/room/dewpoint"
state_class: measurement
unit_of_measurement: "°C"
device_class: temperature
```
Reload the configuration or restart homeassistant server for the new devices to appear.