The following is a list of requirements a WiFi network must meet for your PurpleAir sensor to be able to connect.
If you’ve tried connecting your PurpleAir sensor to WiFi, but it’s unable to connect or won’t show on the PurpleAir map, you’ll first want to follow the steps in our WiFi troubleshooting article. This should include rebooting your router at least once by unplugging it for 10 seconds and plugging it back in. If you have already followed those steps or think you’re experiencing a network problem, continue with the guide below.
When following the troubleshooting steps below, you should regularly check the WiFi Status Indicators for your sensor to see if it has connected due to a troubleshooting step. Even if your sensor says it’s connected at the top of the WiFi setup page, using the status indicators is the only definitive way to determine connection status.
Does the network use a captive portal?
Public WiFi networks (guest networks), like those offered by a coffee shop or university, for example, often use a captive portal network. If the desired local network requires any secondary authentication (like clicking a button on a web page), the MAC address of the PurpleAir sensor will need to be added to the WiFi router.
Some organizations set up a separate WiFi network for PurpleAir sensors to isolate them from other devices. Whether you decide to do this or simply permit the sensor to use the captive portal network, both methods work.
Your sensor’s device ID is the same as its MAC address, with the exception that leading zeros between colons are omitted. For example:
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If a sensor had Device ID 94:45:BF:EA:45:23, its MAC address would be the same.
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If a sensor had Device ID 34:F3:8B:A:53:AC, it’s MAC address would be 34:F3:8B:0A:53:AC. In this case, the “
:A:” in the device ID is singular because the leading zero is being omitted.
Once you have your sensor’s MAC address, it must be added to your router’s allowed list, also known as a “whitelist.” The steps for this vary depending on your specific router.
Is the WiFi router an Eero router, or does it use an IP address within the 192.168.4.0/24 address range?
PurpleAir sensors are unable to communicate with routers that have an IP address of 192.168.4.*, with the star replaced by any number. This most commonly occurs when using an Eero router, as this is their default configuration.
To connect a PurpleAir sensor to an Eero router, you’ll need to follow the steps in our trouble connecting with an Eero router article. Without these steps, a sensor may say it’s connected but will be unable to communicate with PurpleAir or appear on the map.
If this happens, the sensor is connected to an Eero Router, and it thinks WiFi setup is complete. However, the status indicators you can find in the bottom left of the WiFi configuration page will show that the sensor can’t communicate with PurpleAir, meaning it won’t appear on the PurpleAir Map.
Technical Details: This is because PurpleAir sensors use the 192.168.4.1/24 subnet for the PurpleAir-**** WiFi network used during setup. When sending packets to an IP address within this range, they will be routed internally within the PurpleAir-**** network. The sensor will not communicate with IP addresses inside this range on another network.
Is the WiFi network 2.4 GHz (Gigahertz)?
PurpleAir sensors only support 2.4 GHz WiFi networks. If the network you’re trying to connect your sensor to is not 2.4 GHz, it will not appear in “WiFi Settings” when you try to connect your sensor.
Most WiFi routers broadcast both 2.4 GHz and 5 GHz networks. To determine if your WiFi network is 2.4 GHz, you can log in to your router’s settings.
If a 2.4 GHz network is not available, a separate WiFi network using 2.4 GHz must be created if you want your sensor to be online.
To definitively determine if your WiFi network is 2.4 GHz, you can temporarily disable 5GHz on your router and see if the WiFi network is still visible from other devices.
Have You Performed any Advanced Network Configuration?
Advanced networking configurations, like custom filtering, network firewalls, and VLANs, may prevent your sensor from connecting to PurpleAir.
If the problem is that the sensor is connected and trying to send data but does not connect to PurpleAir, you’ll want to allow the hostnames and ports used by PurpleAir sensors. You may also want to add the sensor’s MAC address to the network’s allowed list or “whitelist.”
If you’re still having trouble connecting your sensor to WiFi, you’ll want to try connecting it to a different WiFi network using a more default configuration. If this is successful, you will know that the sensor is functioning properly but that the network configuration is preventing it from connecting. If you don’t have another network readily available, you can also do this using a mobile hotspot from your phone.
WiFi Encryption - Does the WiFi Network use WPA2-Enterprise or WPA3?
PurpleAir sensors can’t connect to networks that require usernames. These are commonly WPA2-Enterprise or WPA3 networks.
WPA2-Enterprise networks are typically used by larger companies and organizations. PurpleAir sensors cannot connect to WPA2-Enterprise networks, and a separate WPA2-PSK network must be set up for the sensor.
WPA3 is also not supported currently.
Learn More
Sensor WiFi and Registration
PurpleAir Sensors Functional Overview
Q: How much power does a PurpleAir sensor draw, and how much bandwidth/data does it use?