recommendations Weather

Backyard weather station

I love sensors. Measure all the things! Home power generation/consumption, air quality, CO2, airplanes flying overhead, infrared, ultraviolet, RF… yah.

So here’s the latest, which I’m immediately adding to the “you should buy” list:

Weather station, installed in my back yard.

That’s the WeatherFlow Tempest Weather System, and it’s awesome. Briefly:

  • Smartphone and web-based displays
  • Simple network protocol, so there’s lots of open source to capture data
  • Innovative, clever sensors – ultrasonics for wind speed and direction, piezo for rainfall. No moving parts!
  • Solar powered
  • Works with or without the internet
  • Also has cool stuff like a lightning sensor (useless in San Diego)
  • Calibrated to lux and watts per square meter
  • Reports UV levels too
  • Precise temp/humidity of course.

Here’s a picture from the vendor:

Basically a does-everything solution. I found it via this TechHive review and got one ordered. It took a few weeks to arrive, but having just installed it, like I say, I’m already a fan. You have to pay more ($329) for the better tech, but having bought and had fail any number of $50 to $100 ‘weather stations,’ I’m ready to buy it once and enjoy it.

You can see my data right here on the web. Buy your own from the vendor here.


You should buy a PurpleAir air quality monitor

Check this out:

Air quality right now in SoCol. One of those is my house.

In July of 2018 I paid $244 to a company called Adrionics for a chunk of PVC stuffed with electronics, the PA-II:

Mine, mounted next to the garage door

It’s a sophisticated, lab-grade piece of hardware – twin laser-based light scattering particulate sensors, and it measures how much junk is in your air. In particular (a pun I am delighted with), the “PM2.5” size range most important to your health and lungs.

It’s rated for indoor or outdoor use. I put mine next to the garage door mainly due to the difficulty of running a power wire outside. Outside is better but you could benefit by having indoor and outdoor if you’re feeling fancy.

You can read about the PMS5003 sensor here, it’s pretty nifty. The PA-II uses twin sensors so you can plot and compare the two readings and thus get better data:

Science! You can connect directly to the sensor (it uses WiFi) and see the full details as well as temp, RH% and breakouts of counts per size range.

Leftover smoke from distant fires, I think.

And even if you don’t own one, head over to and try their map – you can see see local and regional quality at a snap, as with the top image in this post. I can tell, for example, that we’re in fire season as the quality is usually much much better. And if your health is affected (asthma, seasonal allergies or the like) then a sensor makes even more sense. There are other ‘smart home’ air quality monitors with designer enclosures; I don’t recommend them. Do your own research but I found that PurpleAir was a guy who started making these for himself and then for others who asked.

Which, yeah, is a lot like Paul Scurfield in another post in this series. Or Dan Fock.

Each sensor automatically shares its data so you benefit others too – I like that. I’ve done a few experiments with cheap air quality sensors and have come to believe that you can’t get good data without spending a chunk of money, so while this is a non-trivial expense I consider them a good value and recommend buying one.

Or maybe check the map – if someone nearby has one already, then just bookmark the map and benefit from some citizen science.


It’s okay to shower with your dive watch. | planetkris

Great post, via Hackaday. He puts sensors into a watch and torture tests for temperature, pressure and water resistance.

Quite possibly Invicta’s finest hour.


Health recommendations Uncategorized

The world in ultraviolet

After watching this very cool video I went shopping for a UV camera. They are super rare, much harder to find than the infrared camera I got some time ago. I found the Sunscreenr for $80:


There seem to be, at present, none that are iOS compatible, so this was the best option that I could find. It’s took a while to find an Android device from the pile and get it working. (I had to buy a special USB OTG cable to connect my Yubikey for 2FA, really silly!) but its up and working, and friends, the world in UV is weird:

Things to note: My glasses reflecting and blocking UV (just like it says on the tin), skin damage seems more visible, and my light grey car looks almost black. The sky is grey and my daily face sunblock seems pretty good.

So far, it’s money well spent – I’ve already used it as quality control on the kids’ application of sunblock. It’s a good investment if you live someplace as sunny as this.