Who else is using the PoE to the Air Sensor?

I am here to configure and learn about the connections and how does the PoE work with the PA II sensor without the ugly power cord hanging on the exterior wall towards my nearest power outlet. My new idea as i have already receive a good answer from Kurt and just wondering if Others are doing the PoE set up with your air sensor device. Looking forward to seeing more ideas before I locate the air sensor at the perfect spot near my weather station

Is PoE possible with the devices? Please tell me how, I’d greatly like to do. Right now, I don’t like to have WiFi on all the time, so only when needing to view air quality. PoE would allow it 24/7.


P.S. Would also allow removing the power supply as well, as you stated.

Just use a 5V PoE splitter like this: https://a.co/iaFt5RI
You won’t be using the Ethernet connection for data, just power.

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Hi Robert. POE is Power Over Ethernet. It just provides device power through the ethernet cable (CAT5, CAT6e, etc.) It does not, by itself, provide the necessary protocols for network communications. Normally, if you’re using POE, you have a network device that will accommodate that network connection (i.e., has an RJ45 jack, capable of hardwired connection, etc.).

But in the case of the PA sensor, I do not believe the existing models have the capability to be “hardwired” via an ethernet cable. They are designed to use wireless network connectivity only.

So why use POE if PurpleAir doesn’t have an RJ45 jack to accept a network or POE connection? Simple, the PA sensor requires 5v .08 amps of DC power in the physical form of a USB connector. It does not care how you provide that power, as long as it’s stable, correct voltage and current, and is in the form of that USB connector.

A simple “POE splitter” takes the power from the ethernet cable and converts it into a USB connector.

So to do away with the messy electrical cords hanging from the side of the house just to power the sensor, one can simply use a POE source to power the sensor. It’s the same power, just provided in a different manner. In my case, I already had POE capabilities in my rafters for other devices, so it was very simple to provide another connection for my sensor (see my pictures on this thread: Relocating Sensor and Power resource issue - #2 by KurtH)

Keep in mind that this configuration does require an ethernet cable and a POE capable device to feed that POE power (i.e., switch, injector, etc.). But it’s much simpler to run an ethernet cable on the outside of your house that it is to mess with 120v AC cables, connections, etc.). Much safer too.

As with anything, the devil is in the details. What works for me may not work for you or others. But modifying the configuration to meet your requirements is easy, and it simplifies the entire cable run/configuration.

While I do not advocate for any specific equipment vendors, I do recommend using POE technology when it can benefit and simplify your needs.

Did that at least answer some of your question?


Hi Kurt, thanks for the detail response. It does answer my question - unfortunately, confirms coverage for one aspect (powering), but does not support the ultimate goal - not needing Wi-Fi, so the unit can collect and report data 24/7 (versus on demand/limited activation of Wi-Fi). I already have external POE devices transmitting, so the POE connection would be trivial, . But what I want, and hope PurpleAir will someday support, is data transmission as well via ethernet/POE.

Thanks again,

Thanks, noted, as also relayed via KurtH. As replied to Kurt, this doesn’t get me the ultimate goal of 24/7, POE enabled ethernet data collection (no reliance on Wi-Fi).


They’d need to revise the hardware and firmware. Right now it’s based on an ESP8266 which has no native Ethernet interface so they’d have to add an external (probably SPI-based) Ethernet module. Or they could change to the ESP32 which has a built-in Ethernet MAC.

There is a lot of stuff out there to convert PoE to usable voltage, but since we cannot use that for data I opted for a Hubbell USB15AC5WWR outlet and a standard short USB cable. It has been running in this configuration for about a year and a half and looks aesthetically pleasing whenever I see it.

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I’d really like to reduce the dependency on my house WIFI (i.e. turn it off). But I guess until PA makes a version with ethernet data support, that’s not possible (doesn’t seem that will happen anytime in the near future). There’s no technology that would provide a local, low voltage WIFI, just for the purpose of connecting to the meter (and mounted close to it) I assume? I can get a POE cable out to it, no problem.