Adding External Sensors to the Weather Station

We recently introduced a simple weather station that measures humidity, temperature and light from a waterproof container. In this post we’d like to make things more interesting by adding external sensors.


We’ve decided to go with 3 Grove sensors, connected to the relayr cloud via a Particle Photon:

  1. A Gas sensor
  2. A UV Sensor
  3. A Barometer

Below is a step by step tutorial to walk you through the stages of adding these external sensors to your weather station.


External Sensor Supply List

External Sensor Supplies


To get started you'll need to gather the following:

  1. The weather station built in stage 1
  2. Gas sensor
  3. UV Sensor
  4. Barometer
  5. Cables
  6. Flat and round files
  7. Caliper
  8. ‘Dremel’ drill
  9. Flat and round drill bits (around 1 cm in diameter)

The Process



We’ll start with the Photon and provide it with access to a power supply via a USB cable. Much like with the Master Module in the Weather Station Tutorial.

  1. Measure a gap of 6 mm and mark the distance.
  2. Place the markings about one thumb from the lower rim of the container.
  3. Drill two holes at the marked spots.
  4. Use a flat file to refine the edges of the hole.




  1. Insert the USB cable and secure it in place with the use of the hot glue gun.
  2. Measure the width of your gas sensor.
  3. Mark the width of the sensor board on the container - again, about a thumb’s width from the rim.
  4. Use your largest drill bit to drill a hole.




  1. Enlarge the hole to fit the gas sensor with the help of a dremel drill. This can get loud- so brace yourself!
  2. Make sure that the sensor fits snugly.
  3. For the UV sensor, measure around 20 mm in width and mark it.
  4. Measure 1.6 mm in height. Mark that as well.




  1. Measure an additional 3.6 mm in height in the middle of the marking.
  2. Use the flat drill bit to drill a hole.
  3. Enlarge the hole with the flat file.
  4. Create space for the sensor with the round file.




  1. Make sure the sensor fits in nicely.
  2. Draw the contours of the barometer about 1 cm from the bottom rim of the container.
  3. Repeat the drilling process, similar to the one for the UV sensor.
  4. Make sure the sensor fits in nicely.


The next stage will be connecting all sensors to the Photon. The following chart displays which cable should be connected to which pin:


Sensor / Cable Barometer Gas UV
White D0    
Yellow D1 A1 A0




  1. Once all connections are in place, place the Photon inside the box.
  2. Connect the Photon to the USB cable.
  3. Insulate the sensors and secure them in place with hot glue.
  4. Make sure not to cover the actual sensors with glue - only the circuitry.




Connect the the Master Module and the Photon to a power supply via the USB cables.

And… you are done!


Your new external weather sensors are ready to be added to the cloud. To find out how to create a prototype with these sensors on the relayr cloud, check out the code and the instructions on github. You can also use the repository to learn how to add the readings to your web dashboard.