Beefed up Sensoring

A friend bought a couple of Sensirion SEN54s and I helped him get one working, and ended up buying the extra from him. It had been a few years since I researched what sensors were out there that worked well with Raspberry Pis, and were more on the industrial side than the hobbyist side. I was immediately enthused by Sensirion’s documentation, and their sensor looked top notch. My friend did all the homework on reading specs and comparing with others, it was really a no brainer.

With this SEN54 we’ve gained:

  • accurate humidity (the previous sensor was worthless)
  • VOC
  • PM1.0
  • PM2.5
  • PM4.0
  • PM10.0

It’ll be interesting to see the patterns. I’m honestly a little worried about what the particles will reveal seeing as we’re running 2 wood stoves in the house for half of the year. Reassuringly, the first few readings show we’re in the green, but then Nicole opened the stove to let out a bunch of grilled cheese sandwiches and the readings skyrocketed well above WHO guidelines for particles.

But those are only delicious cheese particles finding their way into your nostrils, surely that can’t have and adverse health effect. Jokes aside it’s interesting to see how much of a tail this benign event has. I’ll be really curious to discover more, I really have no idea what I’m looking at yet.

I am very glad to see the Pis become established as industry capable devices. It’s honestly remarkable what I’ve thrown at them over the years while they kept serving their purpose.

GPIO 2 Inverter

I figured out a way to turn our inverter on and off with a Pi so I can leave it off when Winter forces us to be frugal. It takes a little more than an amp hour just sitting there doing nothing, so I do like to turn it off. This capability will serve to automate the fridge in the future, before I do that though, I need to figure out a way to bring cold air from the outside into it. The idea is to have a logic which looks at outside temperature, solar status, and fridge temperature to decide if we just turn it on or if we can simply (and for less electricity) fan in cold air from the outside.

Running a fridge on the coldest months, when solar power is scarce, is doubly absurd.