https://github.com/grgomariani/nvidia-jetson-dht22-python
A python library to read temperature and humidity from DHT22 sensor
https://github.com/grgomariani/nvidia-jetson-dht22-python
cython dht jetson python-library
Last synced: 5 months ago
JSON representation
A python library to read temperature and humidity from DHT22 sensor
- Host: GitHub
- URL: https://github.com/grgomariani/nvidia-jetson-dht22-python
- Owner: GrgoMariani
- License: gpl-3.0
- Created: 2017-10-02T08:58:15.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2019-07-30T17:18:49.000Z (about 6 years ago)
- Last Synced: 2025-04-24T03:47:48.253Z (5 months ago)
- Topics: cython, dht, jetson, python-library
- Language: C
- Size: 22.5 KB
- Stars: 15
- Watchers: 1
- Forks: 5
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
## DHT22 NVidia Jetson Python
A python library to read temperature from your DHT22 sensor connected on GPIO pins of your Jetson Development Kit.
## DHT11 support
Also added a DHT11 sensor read - However this should be tested by someone.
## List of supported Jetson boards
* TX1
* TX2
* Xavier
* Nano
Check the `jetsonGPIO/jetsonGPIO.h` for defines. It should be obvious which is which.
### Prerequisites
Install python-dev
```
sudo apt-get install python-dev
```
This repository relies on a fork I made. To clone the repository use:
```
git clone --recurse-submodules -j8 https://github.com/GrgoMariani/NVidia-Jetson-DHT22-Python
```
### Setup
Edit C_DHT.c to edit the pin number you wish to use to communicate with your DHT22.
Default set to:
```
#define PIN0 jetsontx2_pin37 //2-pin from bottom left
#define PIN1 jetsontx2_pin29 //6-th pin from bottom left
```
If you don't know the pin numbers google __Jetson gpio pinout tk1/tx1/tx2/xavier__
### Install
Download project and install the python library:
```
cd /path/to/this/dir/
sudo python setup.py build
sudo python setup.py install
```
Now your python library is set up on your Jetson.
### Usage
To read sensor enter python as superuser
```
sudo python
```
Once in python
```python
import C_DHT
C_DHT.readSensor(0) # if used with DHT22, read first sensor
C_DHT.readSensor(1) # if used with DHT22, read second sensor
C_DHT.readSensorDHT11(0) # if used with DHT11 sensors
C_DHT.readSensorDHT11(1) # if used with DHT11 sensors
```
### Other
The library is written in C so it should run faster than python implementation would. DHT22 sends signals which need to be caught every 50 microseconds (not mili, micro).
The function C_DHT.readSensor(pinNumber) returns (temperature, humidity, 0 or 1) triplet as result.
If the last value is 0 the communication failed so try again in 2 seconds. If 1 simply read the temperature and humidity.
The code sets the communication w/ the sensor on its own thread so it minimizes the chances of interrupt.
Don't expect to get a reading every time you try to call the function. Give it a few times.
~~You can also modify it to read from DHT11 or DHT21 as well.~~ (Done recently)
Datasheet on: https://cdn-shop.adafruit.com/datasheets/Digital+humidity+and+temperature+sensor+AM2302.pdf