This is a simple weather station that will detect wind speed, temperature and humidity using a Raspberry Pi.
This station uses a small magnet to trip a reed sensor everytime the wind blows the top of the anemometer. Once the sensor is tripped the time is recorded. When there has been 25 trips, a certain distance has been traveled by the magnet. That distance is divided by the ammount of time elasped between the 1st and 25th sensor trip. This then yields the speed of the wind.
Anemometer Cirumference is measured using the radius of the magnet's spin
Watch a test in action! https://youtu.be/fI_jUFqnNJo
To calibrate the anemometer the speedtest.py program can be used, where you can replace "tire" with a revolving object of a know speed. I had a DC motor but I did not know its true speed so my calibration test was flawed. The theory is there though and the math is sound.
I initially tried a IR sensor to detect the spin, but once the top of the assembly was closed the inside would equalize to on ambient temperature. Without a change in temperature to detect, the sensor "failed" in its purpose. The reed and magnet duo worked just as intended.
The final program is in test7.py. There are also tests for the DHT11 sensor, minireed sensor and LED. This Anemometer has not been calibrated yet and it if the DHT11 sensor is placed in the housing with the reed sensor the temperatures may reported higher than actual conditions. To ensure that the whole assembly does not overheat and melt, reflective tape should be wrapped around the housing and on the anemometer or a heat resistant material should be used.
Future add-ons will be to integrate a SQL database and a phone app to get historic data. It may be possible to integrate a barometer into the system to help an AI possibly forecast the weather.
- Anemometer
I would like to give credit to this creator for making the Anemometer. https://www.thingiverse.com/thing:2875873 Thank you.
- Fan Mount
I would like to give credit to this creator for making the 30mm fan mount for the Raspberry Pi. https://www.thingiverse.com/thing:3768077 Thank you.
- Case
Here is my box that houses the Raspbery Pi. It's a bit thin and should be kept out of the sun. My green house has killed many of my weather nodes. https://www.thingiverse.com/thing:4679757
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install python3-pip
sudo pip3 install --upgrade setuptools
sudo apt-get install -y python3 git python3-pip
sudo update-alternatives --install /usr/bin/python python $(which python2) 1
sudo update-alternatives --install /usr/bin/python python $(which python3) 2
sudo update-alternatives --config python
pip3 install RPI.GPIO
Settings:
sudo raspi-config
Enable SPI
Enable I2C
sudo apt-get install python-rpi.gpio python3-rpi.gpio
sudo apt-get update
sudo apt-get install build-essential python-pip python-dev python-smbus git
git clone https://github.com/adafruit/Adafruit_Python_GPIO.git
cd Adafruit_Python_GPIO
sudo python setup.py install
sudo pip3 install adafruit-blinka
sudo pip3 install adafruit-circuitpython-ssd1306
sudo apt-get install git
git clone https://github.com/adafruit/Adafruit_Python_SSD1306.git
cd Adafruit_Python_SSD1306
sudo python setup.py install
sudo apt-get install pigpiod
*Adafruit Perma-Proto 40-Pin Raspberry Pi Breadboard PCB Kit - with 2x20 Header
*DHT11 Temperature Humidity Sensor Module Digital Temperature Humidity Sensor 3.3V-5V
*I2C IIC 12864 128X64 Pixel OLED LCD Display
https://www.amazon.com/gp/product/B076PNP2VD/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1&fpw=alm
*KY-021 Mini Magnetic Reed
*Magnet
*Raspberry Pi 30mm fan and heat sinks