SDS011 Frontend made for Octoprint: https://github.com/sn4k3/Octoprint-SDS011
Adapted from: https://opensource.com/article/18/3/how-measure-particulate-matter-raspberry-pi
First steps
sudo apt install git-core python-serial python-enum lighttpd pip3
pip3 install https://github.com/ikalchev/py-sds011/archive/master.zip
sudo pip3 install https://github.com/ikalchev/py-sds011/archive/master.zip
sudo chown $USER:$USER /var/www/html/
sudo chgrp -R $USER /var/www/html
sudo usermod -a -G www-data
sudo usermod -a -G $USER www-data
git clone https://github.com/sn4k3/SDS011-Frontend.git sds011temp
rsync -a sds011temp/* /var/www/html/
rm -rf sds011temp
chmod +x /var/www/html/scripts/aqi.py
chmod +x /var/www/html/scripts/aqi3.py
echo [] > /var/www/html/assets/aqi.json
sudo chmod 664 /var/www/html/assets/aqi.json
sudo lighttpd-enable-mod cgi
sudo service lighttpd stop
sudo chown -R $USER:$USER /var/log/lighttpd
sudo chown -R $USER:$USER /var/run/lighttpd
sudo chown -R $USER:$USER /var/cache/lighttpd
To test if the aqi.py script is OK you can run:
python3 /var/www/html/scripts/aqi3.py debug
(You need to force quit when you ready, CTRL + C)
Run the script automatically so that we don’t have to start the script manually every time, we can let it start with a cronjob, e.g., with every restart of the Raspberry Pi. To do this, open the crontab file:
crontab -e
and add the following line at the end:
@reboot python3 /var/www/html/scripts/aqi3.py start > /dev/null 2>&1 &
Otherwise if you prefer to start the sensor manually from web use the following line to put sensor at sleep each boot:
@reboot python3 /var/www/html/scripts/aqi3.py stop > /dev/null 2>&1 &
Now we must configure the http server, open the configuration file with:
sudo nano /etc/lighttpd/lighttpd.conf
Add "mod_expire" to "server_modules".
Add this section:
expire.url = (
"/assets/" => "access 0 days",
"/index.html" => "access 0 days"
)
Modify "server.port", i use 81, but you can choose.
Modify "server.username", and "server.groupname" to pi
server.port = 81
server.username = "pi"
server.groupname = "pi"
Modify /etc/init.d/lighttpd. Change 'www-data' to 'pi'.
sudo nano /etc/init.d/lighttpd
from: install -d -o www-data -g www-data -m 0750 "/var/run/lighttpd"
to: install -d -o pi -g pi -m 0750 "/var/run/lighttpd"
Modify /usr/lib/tmpfiles.d/lighttpd.tmpfile.conf and change www-data to pi.
sudo nano /usr/lib/tmpfiles.d/lighttpd.tmpfile.conf
from: d /var/run/lighttpd 0750 www-data www-data -
to: d /var/run/lighttpd 0750 pi pi -
Modify '/etc/lighttpd/conf-enabled/10-cgi.conf' with sudo nano /etc/lighttpd/conf-enabled/10-cgi.conf and put the content:
server.modules += ( "mod_cgi" )
$HTTP["url"] =~ "^/cgi-bin/" {
alias.url += ( "/cgi-bin/" => "/var/www/html/cgi-bin/" )
cgi.assign = (
".py" => "/usr/bin/python3",
)
}
Save, exit and reboot: sudo reboot
Now it must display the page, go to your web browser and test, eg:
http://octopi.local:81
OR
http://IP:81
There are small things that you can adjust:
/var/www/html/scripts/aqi3.py
Note: Changes under this file require a reboot or kill the process and re run.
SERIALPORT = "/dev/ttyUSB0" # USB port where SDS011 is
# This will influence the accuracy and speed of readings, keep a good balance
# Less reads = Less precision and fast
# More reads = More precision and slow
# After measurements the sensor, laser and fan will be turn off for 'UPDATE_FREQUENCY' time, this will increase the lifespan of the sensor.
READINGS = 5 # Number of readings, this will not perform an AVG, only the last read will be used as value.
SLEEP_BEFORE_FIRST_READ = 10 # Time to wait in seconds after sensor awake and before the first read. Give sometime for the sensor stabilize
SLEEP_BETWEEN_READS = 2 # Time to sleep in seconds between each read, total read time will be READINGS x SLEEP_BETWEEN_READS.
UPDATE_FREQUENCY = 60 # Update frequency in seconds, new measurements after that time.
# If UPDATE_FREQUENCY = 0, the sensor will never turn off, this will wear your sensor much faster.
# (according to the manufacturer, the lifespan totals approximately 8000 hours).
STORED_READ_NUM = 100 # Maximum number of readings to plot or store, when max is reached, the oldest read will be removed./var/www/html/assets/aqi.js
var AQI_CONFIG = {
UPDATE_FREQUENCY : 60, // Default seconds to auto refresh the data if not specified by the user via url.
MIN_UPDATE_FREQUENCY : 10, // Min seconds for the refresh frequency, must be greater than 1, if user use lower than that, the value will be set to this.
SHOW_AQI : true, // Show AQI index values by default or only pm values
GRAPH_WIDTH : 720, // Set the graph width, note the graph is responsive
GRAPH_HEIGHT : 420, // Set the graph height, note the graph is responsive
GRAPH_MAX_DOTS : 50, // Set the max dots to show on the graph
};URL Parameters
Use url parameters like: http://url:port/?param1=value¶m2=othervalue¶m3=value
refresh=60 // Seconds to auto refresh the data, use 0 for manual refresh only. if not set AQI_DEFAULT_UPDATE_FREQUENCY will be used.
showaqi=0 // Show AQI index values or only pm values
graphwidth=720 // Set the graph width, note the graph is responsive
graphheight=400 // Set the graph height, note the graph is responsive
graphdots=50 // Set the max dots to show on the graph
AQI API
URL: http://url:port/cgi-bin/aqiapi.py?action=xxx
Replace 'xxx' with a action:
start # Start sensor
stop # Stop sensor
resetdata # Reset the collected data
status # Get the sensor status, 0 = Off | 1 = On
If you wish to update/reset your frontend and lose any changes you have made:
git clone https://github.com/sn4k3/SDS011-Frontend.git sds011temp
rsync -a sds011temp/* /var/www/html/
rm -rf sds011temp
chmod +x /var/www/html/scripts/aqi.py
chmod +x /var/www/html/scripts/aqi3.py