camputer-server

Installation

After connecting the pi:

$ sudo apt-get update -y
$ sudo apt-get install python3-pip git
$ git clone https://github.com/neilb14/camputer-server.git
$ cd camputer-server
$ pip3 install -r requirements.txt

Create and initialize the sqlite database:

$ $ sudo apt-get install sqlite3
$ sudo mkdir /var/db
$ sudo chown pi:pi /var/db
$ python3 create_db.py -l -c camputer.config.ProductionConfig

Omit the -l flag above to avoid adding dummy readings.

Ensure that you can host the flask app:

$ python3 production.py runserver

And in another shell:

$ curl localhost:5000/sensorreadings/last?name=temperature

You should get a dummy sample that was loaded in the create_db.py script.

Setup UWSGI

$ pip3 install uwsgi
$ ~/.local/bin/uwsgi --socket 0.0.0.0:5000 --protocol=http -w wsgi:application

And in another shell:

$ curl localhost:5000/sensorreadings/last?name=temperature

You should get a dummy sample that was loaded in the create_db.py script.

Now get it running on a socket:

$ sudo mkdir -p /var/www/camputer
$ sudo chown pi:www-data /var/www/camputer
$ ~/.local/bin/uwsgi -i camputer.ini

Then check that the socket file exists at: /var/www/camputer/camputer.sock.

Now configure UWSGI to start on boot: sudo vi /etc/rc.local and add the following line before the exit:

/usr/local/bin/uwsgi --ini /home/pi/sampleApp/uwsgi_config.ini --uid www-data --gid www-data --daemonize /var/log/uwsgi.log

Then you should be able to start the service by running:

$ sudo systemctl start rc-local.service

Then ensure that the socket exists in: /var/www/camputer And tail the log at: /var/log/uwsgi.log to see if there are any errors. The output in the log should be similar to the output seen in the previous commands.

Setup Nginx to host UWSGI app

$ sudo apt-get install nginx
$ sudo rm /etc/nginx/sites-enabled/default
$ sudo vi /etc/nginx/sites-available/camputer

Edit the camputer site with the following:

server {
 listen 80;
 server_name localhost;

 location /api { try_files $uri @app; }
 location @app {
   include uwsgi_params;
   uwsgi_pass unix:/var/www/camputer/camputer.sock;
 }
}

Then create a symbolic link in sites-enabled:

$ sudo ln -s /etc/nginx/sites-available/camputer  /etc/nginx/sites-enabled

And restart NGINX:

$ sudo service nginx restart

Finally test it out:

$ curl localhost/api/sensorreadings/last?name=temperature

Enable sensors

Best to update the pi and firmware:

$ sudo apt-get upgrade
$ sudo apt-get install rpi-update
$ sudo rpi-update

Enable the DS18B20 temperature sensor

From the Adafruit DS18B20 Guide Plug the temperature wire into GPIO4 (jumper 7)

$ sudo vi /boot/config.txt

Add the following at the bottom of that file:

dtoverlay=w1-gpio

Then reboot.

$ sudo modprobe w1-gpio
$ sudo modprobe w1-therm
$ cd /sys/bus/w1/devices
$ ls
$ cd 28-xxxx (change this to match what serial number pops up)
$ cat w1_slave

Should see a temperature reading.

Next run the python script (note, only runs with Python 2):

$ cd ~/camputer-server/scripts
$ python2 ds18b20.py
$ curl localhost/api/sensorreadings/last?name=outside 

And should see the sensor reading inserted into the database from the script.

Enable the AM2302 temperature, humidity sensor

Follow ModMyPi instructions to install the Adafruit_Python_DHT libraries.

If you plug the sensor wire into GPIO17 (jumper 11) then no parameters are required to run the script:

$ cd ~/camputer-server/scripts/python2
$ python2 am2302.py

Should print a temperature and humidity reading. Also will write a record to the database.

$ curl localhost/api/sensorreadings/last?name=temperature
$ curl localhost/api/sensorreadings/last?name=humidity

Should return readings from running the script previously.

Darksky Weather

Script grabs the current weather from Darksky API:

$ python3 fetch_temperature.py -k DARKSKY_API_KEY -u http://localhost:8080

Core Temperature

Script to grab the core temperature of the Pi. The upper temperature limit for the Pi is 85C.

$ python3 core_temperature.py

Run scripts automatically through cron

crontab can look like:

*/5 * * * * python2 /home/pi/camputer-server/scripts/python2/ds18b20.py
*/5 * * * * python2 /home/pi/camputer-server/scripts/python2/am2302.py
*/5 * * * * python3 /home/pi/camputer-server/scripts/core_temperature.py
*/15 * * * * python3 fetch_temperature.py -k DARKSKY_API_KEY -u http://localhost:8080