I’ve added an air quality monitor to my weather station. This uses a laser to measure the particle concentration between 0.3 to 10µm in the air. The sensor is the silver and black unit at the left, and has a small fan which sucks the air in from the outside via a small tube which you can just see going through the garage wall to the outside.

There is a more detailed explanation of the sensor Here

The output from this sensor are two values for PM2.5 and PM10, both measured in µg/m³. This graph shows the PM2.5 value for the last 24 hours – it’s still a bit high as the unit is still settling down:

You can see the results from this, and my other weather sensors, by viewing http://home.wsn.uk:5555 username ‘view’, password ‘view’. Click on the icons to see the graphs showing these inputs change.

See A Weather Station for the original post on this project.

I needed to create some fittings to hold some 12V LED lights used for emergency lighting, which was a good excuse to do a bit of 3D design and print them on the 3D printer:

The slot in the middle is for a connector for the lamp, which fits in from the back:

The 12V lamp then plugs into the socket:

Note the gap around the lamp and the triangular holes to help airflow; the first version didn’t have these and the lamp got so hot that it melted the plastic of the base!

And finally, the working fitting. This will be mounted upside down on the ceiling:

We have an underground storage tank, which was used for irrigation when the surrounding area was an orchard before the house was built. It’s not as deep as it used to be, but still holds around 2000 gallons of water when full. It’s filled from half of our house roof, and all of the garage roof. There is a submersible pump in it which we use to water the garden.

Measuring the water depth has always been a challenge, and you can just see a white measuring stick – but all the markings on this faded over time!

Last year, I purchased an ultrasonic depth sensor which worked fairly well but wasn’t robust enough to survive outdoors.

So this year, I bought an industrial pressure sensor, which now sits at the bottom of the tank:

I found an small microcontroller board that has a suitable input for this – this board also has integrated WiFi so it can send the measurements back to the house.

This sends the data to some logging software running on our Raspberry Pi based server.

This works just fine, but being a pressure sensor, the recorded level varies slightly with atmospheric pressure changes. So a bit more digging found this little board, which measures barometric pressure and temperature:

I found a design for a small “Stevenson Screen” to hold this board, which I printed on my 3D printer:

This also connects to the WiFi board.

You can see the results from these sensors by viewing http://home.wsn.uk:5555 username ‘view’, password ‘view’. Click on the icons to see the graphs showing these inputs change.

The next task is to adjust the Water Level reading with atmospheric pressure!