Topic: PurpleAir PA-II

[waysta]

After watching sensors on the west coast respond to the smoke from the brush fires, I decided to buy a PurpleAir PA-II.

One of my interests is to understand AQI numbers from outdoor burning.  For example, what is the range from a smell of burning smoke to higher AQI numbers of possible concern for health risks?

The unit came nicely packed.  Installation was easy with a single drywall screw installing the sensor to the side of the house under the eves to mounting the outdoor power supply to the wall below the unit.  In both cases I used my own screws, longer than those supplied.  Fortunately, I have already have an outdoor 120V outlet with a weather cover in range (15 feet) and plugged the sensor power supply in there.

The unit powered up fine and connected in minutes following the WiFi procedure.  The web GUI shows RSSI (received signal strength at the unit) and even plots a graph of RSSI with time.  Ironically, everything installed fine, the first time with no problems, so I may never need that RSSI feature, other than to tweek WiFi router antenna positions to see any sig. strength changes at the sensor, just for interest.

My unit is graphing fine on the PurpleAir map.  Not sure how to log data, or if that is possible.  For now, its not a concern.  Standard concerns with reporting through a 3rd party server apply, hopefully that will not be a problem.

The hardware seems well built and solid.  In the "spirit" of much higher cost laser particle counters (and it is a dual sensor - self comparing unit), the cost may not be that high.  Although it is on the higher edge for a home hobby installation, especially considering similar stand alone (not WiFi) lower priced units from CN flooding the market. 

On the other hand, the PurpleAir Web map is very good, and each station graphs significant sensor detail there, both particle count data and sensor hardware health data.

Overall, my initial impressions are very positive.

https://www.purpleair.com/map?&zoom=8&lat=42.851057995157156&lng=-75.7759850692749&clustersize=30&orderby=L&latr=4.067323068869335&lngr=8.272705078125

click on each sensor oval to see the detail for that station, (some selections (e.g. particles) have two rows of tabs, one over the other) to select the various data pages.

[cjohlandt]

I've had my PA-II up for several months now and it just works.  No problems whatsoever.  Brian added support for PurpleAir in Weather Display a couple of months ago, making it easy to pull your AQI data and use on your website.

-Chris

Sent from my XT1650 using Tapatalk

[Eno]

I own a PA-II-SD and look at their map often, but the website isn't developed well for a phone, except last week a Purple Air app appeared on my Samsung S8 and it appears to be optimized for a mobile device.  Just weird that it appeared on the homescreen and I never did anything to put it there.

[Eno]

After about 40 days of working perfectly, the PurpleAir PA-II-SD I installed on November 19 will not stay online. I have been unplugging the power, waiting about 15-30 minutes (shorter time doesn't seem to work), restoring power, then it will appear on the map, but disappear from the map again anywhere from within an hour to 12 hours.  Been up and down a ladder about a dozen times in the last four days.

I've changed some router settings; tried different channels, specified 802.11 n only mode, and got the RSSI down from -70 to -74 dBm down to -59 to -64 dBm.  I don't think it's on my end.  I think it's something in the device itself or something in their network.  The number of offline devices fluctuated from about 49 down to 17 just today, currently at 42.

 

[Skywatch]

I've had my PAII running for about 4 weeks. My uptime fluctuates most likely from being on the other side of the house from the router.

At first during the initial setup it was sending then dropped out after I unplugged the sensor to install it and it dropped the house's WiFi code and after a day of trying to figure it out I had to redo the setup.

I've actually gotten intrigued by the information.  Some days depending on the wind direction I can watch other stations in the area fluctuate then see my numbers change in sequence. It's also interesting to see my AQI high up over 50 then with the passing of a cold front it drop to single digits. Someday I'm going to figure out the Weather Display setup.

[Eno]

After a month of problems trying to keep the sensor online with decreasing success, now even the gray offline dot is gone from the map.

[Forever]

I have had no issues with my unit, have you tried talking to PurpleAir to determine if you have a bad unit?

[Eno]

I have had no issues with my unit

Only 4.5% of the sensors are offline today (only?) so you're one of the lucky 95.5%

have you tried talking to PurpleAir to determine if you have a bad unit?

They've been helpful on the FB users group. They said they will send another unit to "try". But there is no warranty that I can see in their terms of service.

I have a feeling the issue may be something with the ISP that will be hard to figure out and will remain unresolved when the ISP inevitably says it's not on their end. The FB PA users group contains several dozen messages of mine regarding troubleshooting I've done.  Sometimes I get weird messages in the router log, sometimes not.  Sometimes rebooting the router brought the sensor back online, sometimes not.  Sometimes unplugging the sensor and then restoring power to it brought it back online, sometimes not.

Did you see in the WU Issues thread, the WU guy said that there would be a lot of "Internet of Things" sensors, like the PA-II, in the future.  I think I've bought "Internet of Things" sensors twice now, my first and last time.

[ggsteve]

I know this isn't a fair comparison, but I had horrible problems keeping my Rainwise IP-100 and Bloomsky 2 online.  This went on for several months.  Bloomsky even sent me a second unit and it had the same problems.  I finally got Comcast to swap out the router and it was literally like turning on a switch.  All of my problems with the wifi devices vanished.  Been a happy camper ever since, almost a year now.  I'm very interested because I am considering a PurpleAir.

[DaleSpring2]

I sent the following questions to PurpleAir, but have not heard back.  Is someone able to answer these?

1) Regarding the WiFi Configuration.  I am not familiar with the path for connecting to WiFi listed on your website.  I am used to opening a new device and entering my password.  Would I use the 'push to connect' button on my router?  I have not used this method before.

2) Can the unit be placed in an area where it may get wet in the rain?  Or does it need to be under something like a roof eves?

3) How is the "Village Green" air quality measured?

4) When I view AQI on your map it will read one value.  But when I open a meter's information and view the large font size number, that number is often different.  What is used to calculate the large font size number?

[n3b]

I'm happy with my PurpleAir sensor, it doesn't have the SD card, but I don't need to export data, and hope some day WU or other site can show years of history, like WU can.

It's very interesting to see how much just one wood burning neigbour can affect the air quality. Right now it's almost no wind and the value is 160!

Follow it on:
https://www.purpleair.com/map?&zoom=12&lat=59.718461465526005&lng=10.812468551972302&clustersize=30&inc=324152|324154&orderby=L&latr=0.26470138250660824&lngr=0.512237548828125

 ( it would been nice to see some shorter url's like WU have to my weather station: https://www.wunderground.com/personal-weather-station/dashboard?ID=IAKERSHU100 )

[Forever]

I did get the SD version but I have no idea how to access the data. I send PurpleAir an e-mail but they have not replied yet.

By any chance does anyone know how to access the SD card?

[ConligWX]

the only stuff i have seen so far is

http://ip.of.purple.air

and

http://ip.of.purple.air/json   

[Forever]

I'm able to pull live data from the json file but don't see how to get to the SD card.

[Forever]

PurpleAir got back to me and current the only way to access the SD card is to remove it and place it in a card reader.

They are currently working on a firmware update to make it so the SD card can be access remotely.

[waysta]

I've had my PAII running for about 4 weeks. My uptime fluctuates most likely from being on the other side of the house from the router.

At first during the initial setup it was sending then dropped out after I unplugged the sensor to install it and it dropped the house's WiFi code and after a day of trying to figure it out I had to redo the setup.

I've actually gotten intrigued by the information.  Some days depending on the wind direction I can watch other stations in the area fluctuate then see my numbers change in sequence. It's also interesting to see my AQI high up over 50 then with the passing of a cold front it drop to single digits. Someday I'm going to figure out the Weather Display setup.

My unit continues to run well.  Many stations in an area do tend to track a bit (minus the nearby wood burning spikes).  Very pleased with the unit, not a criticism, just wondering if there might be any systematic errors?  Could regional effects be due to similar temperature and humidity combinations?  Or, maybe those type of common temperature and humidity area conditions set the stage for common air quality (such as the ability to support particles in the air)?

[mmorris]

So finely got my PurpleAir install well actually twice. Where I wanted to place it on the far end of the detached garage the wifi would barely make it to the router so I had to move it closer and put it on the other end closer to the router. Any way not a hard job. Then it took 8 hour to get the dam thing on line. You know you click on thing on a web site and it tells you it can't find what your logged onto with a excellent signal so I just registered my location. Then web site said the server was down so I don't know some how I got to some web page that showed all the networks choose mine  entered password and it said it wrote it to the eprom and was restarting the network and it just sat there for ever. So I just disconnect it myself and it never did show up again on the list. I then check the map and it was showing number at my location on the map.
 I have no idea what the IP of this thing is. Also I didn't look around the unit just plugged it in where is the SD card?   

[Forever]

Yah, their setup could use some work.

You should be able to use an phone app like Fing to get the IP.

The SD card is on the opposite side of the power connection between the sensor and the housing.
You will probable need some tweezers to get the card out and back in.

[mmorris]

Thanks

Yah, their setup could use some work.

You should be able to use an phone app like Fing to get the IP.

The SD card is on the opposite side of the power connection between the sensor and the housing.
You will probable need some tweezers to get the card out and back in.

[prestwickwx]

I have been looking at the PurpleAir PA-II and I am curious about the micro usb connection to the Power cable. Is the connector on the PurpleAir Sensor side, a "female micro usb"? The reason I am asking is because I would prefer to use a male micro usb extension cable to get the power supply inside.

Thanks for any info concerning the cables.

[drewcssv]

PurpleAir got back to me and current the only way to access the SD card is to remove it and place it in a card reader.

They are currently working on a firmware update to make it so the SD card can be access remotely.

Have you heard back from PA that they've pushed the remote SD card access? This would be key for my installation. Thanks!