Here’s a video tutorial on how to communicate with and use Alphasense OPC-N2 Optical Particle Counter sensors with Valarm Tools Cloud.

Note: that you can get your housing enclosures for mounting and deploying your Alphasense OPC-N2 sensors here on!

Please don’t hesitate to contact us at if you have any questions!



Voiceover / Transcript:

Howdy! This is Dr. Edward Pultar, PhD, from Valarm. In this video you’ll learn how your organization will use to remotely monitor air quality measured by Alphasense OPC-N2 particulate matter sensors. What you’re seeing is an Alphasense OPC-N2 particle counter that monitors PM1, PM2.5, and PM10 particulates.

The OPC-N2 is connected to a SPI serial sensor adapter that’s connected to a sensor hub. The sensor hub uploads your sensor telemetry information to in real-time. You can have any number of sensors connected to your sensor hubs. And you can get your sensor hubs on that connect to Valarm Tools Cloud by the internet connectivity that’s best for your Industrial IoT application, whether it’s Wireless WiFi networks, GSM cell networks like 3G, or ethernet.

First make sure you’ve got your sensor hubs linked to There’s a 4-minute How to Use Valarm video on our website that will get you going if you don’t already have your sensor hubs on Valarm Tools Cloud.

In the rest of this video we’ll show you how to configure your Alphasense OPC-N2 sensor with the SPI, a.k.a., Serial Peripheral bus, sensor adapter so you can see your particulate matter air quality sensor data in tables, graphs, and maps in 2D and 3D!

To attach your Alphasense OPC-N2 to the SPI sensor module, follow the Alphasense docs and connect your cables to the proper holes like PWR, SS, SCK, SDO, SDI, and GND.

Once you have your Yoctopuce SPI module plugged into your computer via USB for initial configuration then click Configure on your SPI module in virtualhub. You’ll see a screen like this one where you can make sure you’re giving the Alphasense OPC-N2 5V of power, using Frame-based binary protocol for communication, 63Kb/s, SPI mode 1, SS active low polarity, and measuring sensor values with TTL 3.3V.

Under the job files you’ll use the OPC-N2 .job file that you can download on our blog post about the Alphasense OPC-N2 on The .job file scripts perform 2 tasks: 1 is turn on the sensor and its forced intake air fan. The other task is to take a regular measurement from the sensor for PM1, PM2.5, and PM10 air quality sensor readings. You can see the hexadecimal commands in this screenshots and set how often the hex commands are sent based on how often you want to get a new sensor measurement. The dollar sign command arguments in the script mean the sensor readings will be stored in the generic Sensor 1, 2 and 3 fields. After you’ve got the job file configured and set as your startup job then we’ll map the air quality sensor data to column fields on

On your Valarm Tools Cloud Device Manager you can now see the SPI module has reported in your Device Details page. You can map the 3 sensor fields from the OPC-N2 to any output channel field. Remember that the particle counter is reporting PM1, PM2.5, and PM10, in that order. In these screenshots you’re seeing Valarm units we made for the AQMD, the California government agency responsible for air quality monitoring and compliance. In this example we’ve mapped the particulate matter readings to the Calc 1, 2, and 3 fields.

You can use the column renaming tool to set up aliases and name the fields PM1, PM2.5, and PM10 like you see here. Once you’ve got the sensor values mapped you’re all done and you can see your Valarm sensor data on graphs and maps in 2D and 3D like you’re seeing here. The Alphasense OPC-N2 air quality sensor data is now available in all of the screens on Valarm Tools Cloud and via our APIs like JSON.

Now you’ve finished configuring your OPC-N2 with Valarm Tools Cloud!

Note: You’ll purchase your boxes, sensor adapters, harnesses, enclosures, and housings for your Alphasense OPC-N2 sensor units here on




Please don’t hesitate to contact us if you have any questions at

We can help you out if your organization needs Industrial IoT, sensor telemetry, and remote monitoring solutions.

Have a look at our Customer Stories page for stories on how our customers are using IIoT applications.

See our homepage at for more info. Thank you for watching!

Youtube screenshot Valarm Tools Cloud with Alphasense OPC-N2 Particulate Matter Sensors for Industiral IoT Remote Air Quality Monitoring