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Three good things

I had a good Christmas and wanted to share! First off, a Kickstarter that delivered on time, a really good Raspberry Pi case, the Argon ONE:

Assembled case

Here’s the back, showing the magnetic GPIO cover and rearranged port layout. Simple, clean and elegant.

You can get one via their Kickstarter page. It adds a shutdown/reboot circuit, temp-controlled fan, IR LED option, HDMI/audio redirect and a really nice aluminum enclosure with (as seen above) translucent window over the indicator lights. I put a Pi 3B+ into it and plan to collapse three single-purpose Pis onto it. (PiHole, Raven and AWS Greengrass). The cooling fan should help immensely, and the quad-core model 3 with 1GB of memory performs really well, leaving room for more code and projects.

I think I paid either $15 or $20 for it; even at $20 this is a great deal on a well-designed and well-made metal case. The additional cooling should also increase the reliability, lifetime and ability to handle compute loads. Highly recommended.

Echo wall clock

This is my favorite piece of Amazon hardware. It’s a $30 clock, driven by and synchronized with an Echo device using (probably) low-power Bluetooth. It comes with standard AA batteries, sets itself, carries no visible branding and has a spectacular peripheral array of LEDs to show timers:

That’s a 45 second timer counting down. Here’s what you see when I add a second timer – another LED at max brightness:

I’m a plodding cook; I have a few things I’ve learned and I rely heavily on timers for most of them. Having voice-set timers be visible is nice, because a) I can name them (‘oats’) and b) Chris won’t accidentally erase them when using the microwave. Yeah, that happened more than a few times since I used the microwaver timer as a second device.

The downsides of Alexa and Echo are well-known and I’ll not repeat them here, that said music and timers are very useful to me. Here’s the Amazon page for it.

HP multifunction from Costco

We’ve long had an incredible monochrome laser printer, the Brother HL2270DW, bought in 2011 and and running with zero problems for an incredible seven years. Duplex, compact in size, has WiFi/Ethernet/USB, well-priced toner cartridges and, with 24lb paper, jammed four times in seven years!

However, we wanted the ability to print color and, having long used and been burnt by inkjets, it had to be laser. Chris found this HP M281cdw at Costco and it’s worth sharing:


  • Built in support for AirPrint (iOS) and Chrome print (print from anywhere). I had a, you guessed it, Raspberry Pi running Chrome print before plus a desktop MacOS software app to provide AirPrint; this is simpler and works well.
  • Copier and scanner – low usage expected, but there if necessary.
  • 2.4 and 5GHz WiFi support
  • So-so price on refills – black is comparable to the Brother, but it should last a while.

I found a friend who can use the Brother, so it’ll keep cranking for someone else. The HP is a bit larger but so far working great.

It was on sale for around $250 and is now currently $320; still a good deal but you might bide your time for another sale.


Power and energy consumption

I built a system that uses a ‘Raven’ Zigbee USB radio and Raspberry Pi to monitor our SDG&E electric meter, and layered Flask and D3.js on top to display usage.

Sometimes it looks quite cool:

Screenshot 2018-07-18 07.21.01.png

The baseline for the house is 225 to 250W, and the plateaus are the (high efficiency energy star) refrigerator. You can see where I got up, turned on lights and cooked breakfast, too. (Electric range and kettle.)

I’m pretty pleased with our usage and have put quite a bit of effort into reducing our consumption. LED bulbs, of course, but also low power servers and networking (61 watts total!), timer switches on idling electronics and measuring what things use. In-wall insulation is also a huge win year-round.

The code is at this GitHub repo if you want to roll your own.

It’s a weekend or two, but if you’re willing to puzzle it out, the data is nice and it’s purely local – no internet connection needed, no holes in your firewall, no sharing of the data. A few minutes reading should be convincing on why that’s worthwhile.