Three things from this week.

This week there’s more of a common thread between the three things that bubbled to the top.

Home assistant

Home assistant keeps showing up in the periphery for me so I finally made some time to try it out. It’s a self-hosted home automation software that runs well on a Raspberry Pi 4B. I plugged in the RPi to the router, I found a blank microSD card, and imaged it. Shockingly, it booted up and showed up with expected hostname with no hiccups. It immediately discovered the little temperature/humidity monitor I wanted to connect with.

There are a lot of little home automation devices like this around, I think they usually have some ESP32 device inside. Turn the sensor on and it just starts sending out data over BLE. Usually the vendor intends for them to be used with some wonky phone app or something but I don’t need that part.

Getting a quick experiment going was easy and solves my imminent issue - I want to watch the temperature near a fermenter.

Energy

There are a few ways to measure energy usage. Some of them tie in to home assistant but I’ve been getting a feel for things with ad hoc measurements. This week I measured how much power the air fryer used to cook a batch of tofu. It ran for about 14 minutes at 400°F (~205°C) and the meter said it used 0.230 kWh. So I had to ask myself “Is that a lot?". The Kilowatt-hour is a weird unit to me. Writing it as kW⋅h makes it a little more clear that it’s the equivalent of a kW multiplied by an hour; that is it’s one killowatt of power for an hour. Power is energy over time (figuratively but also mathematically calculated using that division) and power is measured in watts so multiplying power by time gets a unit of energy. It’s an okay unit but it’s not a great unit because hours aren’t easy to work with. SI and metric use seconds and powers of ten.

Calling it 0.230 kW⋅h or 230 W⋅h does make it seem like it’d be the same as using a 100W bulb for about 2 hours 20 minutes. That kind of comparison is more practical for me than knowing that it’s 828 kJ. Joules are a better unit for real calculations because a Joule is 1 watt for one second. Unfortunately I don’t have a good frame of reference for Joules. Maybe I should just get used to multiplying and dividing by 3600 since the hour is the common hangup between useful times on the clock and useful units for everything else.

Brew time

It’s time to brew again. During the stay-at-home order times of the pandemic everyone branched out into homey hobbies. I got into brewing at the prodding of a friend of mine.

About a year or so on I started spending more weekends on Gammacam and fewer on brewing. Now that Gammacam is out there we’re getting together to brew in the same place for the first time. Homebrew beer is fun but it’s one of those hobbies that can expand to fill as much time as you want to give it. Brewing has let me learn a lot about things that are way outside my usual routine though so it’s a nice little brain vacation. Plus the beer is usually good.

The funny thing is that brewing from an extract kit is a lot like making a giant pot of tea. With lots and lots of sugar. And instead of tea leaves you dip in a bag of grain. Oh and after it boils for a while, instead of drinking it you pour yeast in and let it sit for a couple weeks. Other than that though, it’s a lot like making tea.

All grain brewing adds a lot of work to the start of the process where you have to get the sugar out of the grain instead of letting someone else prepare that for you. I haven’t done it myself but it’ll be a fun exercise to get involved in. We’ll try for an extract brew and an all grain on the same day. I’m sure it’ll all go very smoothly.

• ttftw