Debugging poor home wifi at the Snell-Pym residence (by alaric)

So, we have a fairly complicated network at home - the Snell-Pym Family Mainframe has a dedicated DSL link with a static IP for hosting various Internet-facing things, as well as providing internal services to the home LAN. The home LAN has the usual mix of desktop computers, the laser printer, and two wireless APs for mobile devices to connect to - one in the house and one in the workshop, because one can't get a good signal to both locations. And there's a separate infrastructure LAN for systems control and monitoring.

Now, we've often had on-and-off poor connectivity on the wifi in the house; this used to happen sporadically, usually for around a day, then just get better. The wifi signal strength would remain good, but packet loss was high (10-20%) so stuff just didn't work very well. TCP is poor at high packet loss; it's OK once a connection is open, but packet loss during the initial SYN/SYNACK/ACK handshake causes it to take a long time to retry on most implementations.

I went looking for interfering networks (we live in a pretty wifi-dense urban area) using an app called "Wifi Analyzer" on my Android phone, and it showed a strange network, always on the same channel as the house wifi (as in, if I changed the channel, it would move too). The network never had a name, and the signal strength was about the same as the house wifi; sometimes a bit stronger, sometimes a bit weaker. Read more »

Redesigning my workspace (by alaric)

So, I work from home - and a lot of my hobbies involve sitting at the same desk, as they're computer-based or electronics-based. My workspace is an outbuilding at the end of my garden, with power and Ethernet connecting it to the house. Half of it is a workshop, and the other half is my computer / electronics lab. The workshop end is pretty good since I made my custom welding bench, but the lab end was just made from furniture I had lying around that fitted in, so has been a compromise for some time. I am forming a plan to fix it!

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The effect of the pandemic on my mental health (by alaric)

I'm definitely not alone in finding the current pandemic a time for difficult emotions, but it's taken me a while to unpick the emotions I've been having. Having managed this, however, I'm documenting them here - as a record for myself, to save me repeating myself when explaining them to people who ask how I'm feeling, and in the hope that it might provide some ideas for people who are still trying to work their feelings out; you might have something in common with me.

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12v DC Power Distribution (by alaric)

What with not needing to spend quite so much of my time driving my family to places these days, I've been catching up on household maintenance, DIY, and vehicle maintenance tasks, and one of those has been to finish a 12v DC power distribution unit (PDU).

Why do I need such a thing? Well, our van has an auxiliary power system - a pair of large lead-acid batteries in the back that are charged from the engine while it's running, which then power internal and external lights, a microwave oven, a mobile amateur VHF/UHF band transceiver, and things like that.

This is useful compared to just running from the vehicle starter battery for three reasons:

1. While the starter battery is optimised for brief, intense, surges of current to start an engine, the auxiliary battery pack is optimised for energy storage so can store a lot more energy more efficiently.
2. If I leave things on and run the auxiliary batteries flat, I can still start the engine from the starter battery (and thus recharge the auxiliary batteries).
3. I can mumble things like "Switching to auxiliary power" and pretend I'm piloting a spaceship.

However, the auxiliary power system was installed in the van's original life as a work crew support vehicle, so it was hardwired to a few appliances and the lights. Somebody who owned it since had attached a set of four "ligher sockets" - perhaps the nastiest 12v accessory socket in common use to a fuse marked as "spare" in the fusebox. But I ripped that out and used the "spare" circuit to run the transceiver instead. On the other hand, where the van had originally had a hot water system for making hot drinks that was removed before it came into our hands, a 50A fused circuit terminated in a large SB50 Anderson connector.

I had nothing that would plug into such a socket, but did want to plug in things such as:

• Chargers for various kinds of batteries I use
• USB sockets for charging phones
• An inverter to run things I don't have DC power supplies for
• Amateur radio equipment (which usually runs at 12v from 30A Anderson Powerpole connectors)

So the solution was obvious: Make a Thing that plugs into the 50A socket, and then itself has lots of different sockets on so I can plug stuff in. Desirable extra features are:

• Individually fusing all those outputs, as if most of them pulled 50A in a short circuit (which the upstream circuit can provide) it probably wouldn't end well.
• Integral voltmeter so I can check the battery status.
• Usable in other off-grid power situations as well.
• A commonning point for RF grounds for antennas and ground stakes and stuff for radio gear.

The design

So I settled on the following design:

• SB50 connector on the end of a few metres of nice flexible 8AWG silicone-insulated cable, to plug into the van.
• Incoming +ve splits into an eight-way blade fuse box I had lying around
• Two lighter sockets, for legacy devices.
• A panel-mounting 12v-fed USB charger, with two outlets (with a power switch, as it draws a tiny idle current even when not in use).
• A voltmeter, powered through a pushbutton so it's not draining the battery when not in use (I ran this from the same fuse as the USB charger).
• A set of binding posts, for attaching arbitrary wires or banana plugs (also useful as a power INLET by hooking up my bench PSU in the workshop).
• Four 30A Powerpole sockets.
• Four banana plug sockets for RF earthing, joined together, with a switch to join them to the -ve DC power line (I can turn it on to bind RF earth to DC -ve at the box, or turn it off to break a ground loop if it's bound elsewhere - basically, just fiddle with the switch and see which produces less noise in the current situation).
• Every output has a ceramic 100nF filter capacitor in parallel across it, to try and cut down on power line noise.

Then, as the supporting cast:

• A set of battery clamps hooked up to another SB50 via a 50A fuse (plus a single Powerpole connector on a 20A fuse in parallel so I can plug small stuff in directly) so I can also run the system away from the van, from an old car battery in my possession, or nicer deep-cycle batteries I might own in future.
• A powerpole connector with a 5A fuse hooked up to a little 1.2Ah sealed lead acid battery I happened to have lying around, so I can run the system away from the van without lugging a huge battery around at all, for small loads only.

Building it

Electrically, the system is dead simple. But mechanically, fitting it all in the box and making it sturdy enough to survive camping trips was challenging.

• Cables capable of carrying 50A without a problem are bulky
• I didn't have panel-mount Powerpole connectors, so needed to improvise.
• The fuse box I had just had spade terminals for each end of each fuse, without a common busbar.
• The fuse box was meant for mounting to a bulkhead; I wanted the fuses to be accessible from outside the box, while keeping all the spade terminals inside the box so no live stuff was easily pokable.

I dealt with the latter point by cutting a rectangular hole in the front panel so that fuses could stick up, while the electrical connections where beneath the front panel. Long screws through the front panel went down through the mounting holes on the fuse box that should have mounted it to a bulkhead, and a nut on either side of the mounting flange held the fuse box in place at a fixed distance behind the front panel so the fuses stuck out enough to be easily accessed, while the spade terminals were kept amply away from the front panel. I covered the back of it in insulating tape, just in case.

To common the positive connection in, I crimped a massive ring terminal onto the incoming positive wire (I had to buy a special massive hex crimper to do this!), and bolted it to a strip of thick copper I cut to size. I drilled eight holes in it such that I could pull the insulation off of eight female spade terminals and solder them into the holes, then press the entire strip onto the spade terminals along the top of the fuse box, thereby commoning them. Lots of insulating tape and heat shrink then covered all the live (and directly connected to the 50A incoming circuit) parts.

For the Powerpole connectors, I 3D printed some mounting places with suitably sized rectangles, then used them as a guide to cut slightly larger holes in the metal case. I had PCB-mounting powerpoles connectors, which I soldered the filter caps directly onto the backs of, then soldered the negative lines together to common them. Wires were soldered onto the common negative and individual positive lines, and protected with heat-shrink.

I then poked the connectors into the holes (they were a push fit) and used generous gobs of Sugru to protect them against being pulled out or - worse - pushed in. Since Sugru is slightly flexible, I increased the rigidity of the setup by using a length of thick steel TIG welding wire across the backs of all the connectors, embedded in the sugru (and electrically isolated from everything).

I couldn't easily fit filter caps onto the lighter sockets and the USB charger, as they used crimped spade terminals, so I made a bank of filter capacitors fitted to a screw terminal block on the front panel. I glued it in place with epoxy.

Here's a shot of the interior partway through construction, to give you an idea:

I put in 15A fuses for the lighter sockets, a 3A fuse for the USB and voltmeter, 10A for the binding posts, and a range of fuses for the powerpoles - 10A, 10A, 20A and 30A.

Finally, to document what each fuse drives, I put a simple schematic of the circuit on the outside - by drawing lines with a permanent marker from each fuse to its load (going via the switch in the case of the USB outlet).

The finished product

Once all those fiddly details had been addressed, and many many crimp connections made, I was delighted to find that the box would close with only gentle pressure!

I carefully tested it for short circuits with a meter and, none found, gingerly plugged it into my bench PSU through the binding posts on the front and crept the current limit up from zero... it didn't explode!

So, I plugged the small sealed lead-acid battery into a Powerpole socket and tested the internal voltmeter:

It doesn't show so well in the nice sunlight we've been having, but that's registering a healthy 12.79v. And not catching fire or exploding.

Next, I plugged it into the car battery using the big SB50 plug, and checked the voltage with my multimeter on the binding posts:

Also all good. Finally, I plugged a USB voltmeter into a USB outlet and turned on the outlet:

(And, of course, I checked every outlet with the multimeter to make sure everthing was connected properly and all of my fuses were good).

So, with testing complete, it was time to put it to work. I was due to check the tyre pressures on the van, so I plugged the SB50 into that auxiliary power socket that started this whole adventure, and plugged my tyre compressor thingy into a lighter socket, and did all the tyres - after quickly checking how the auxiliary batteries were doing, as I'd not driven the van in weeks:

The pump actually draws eight amps according to the label on the underneath, so this was a test of the system under non-trivial current. It still didn't catch fire.

Things I'd do differently

• Use proper powerpole panel mounting outlets. Doing it myself was skanky.
• Put a handle on the thing. As the surface is so covered in sockets and things, it's not actually easy to hold it. Fine when it's sat on a surface, which is what I designed for, but carrying it around feels ungainly.

What next?

I've already got a 240v AC inverter and various chargers with Powerpole connectors, but I want a few more Powerpole accessories:

• Lighting strips on hooks, so I can set this up inside a tent and light the tent (while also charging all my batteries). I've ordered some cheap 12v LED light strips; I'll put cables with Powerpole connectors on them.
• A plugtop 12v mains PSU, so I can run this lot from a wall socket easily (for small loads).
• A DC-DC 12v battery charger, so I can charge my car battery and my little sealed battery from the van's auxiliary power system (just wiring 12v batteries to each other isn't a good way of charging them...) or, in an emergency, charge the van's starter battery from the auxiliary power system.
• A portable solar powered 12v battery charger for free, clean, energy.
• A boost-converter DC power supply for my laptop, so I can run it without the wasteful step of running an inverter to generate 240v AC for my laptop charger to drop back down to 18v DC.

Time (by alaric)

As I often complain to those around me, I'm a very busy person. I'm the only driver in a family of five (myself, Sarah (who has medical issues), Jean, Mary and Sarah's mother (who has medical issues)), and I have a 9-5:30 job (well, as I take a lunch hour AND an hour to pick Mary up from school it takes from 9-6:30 instead), so there's plenty of demands on my time.

For most of my year, my weekdays look like this:

1. Alarm goes off at 6:30am. Get up at 7am, start getting Mary up and ready for school, get myself ready.
2. Leave the house at 8am, drive Mary to school.
3. School opens up at 8:30amish, when I can drop Mary off and go home.
4. 9am: Start work.
5. At some point: lunch hour, making lunch for Sarah and I, eating it, possibly a few little household chores.
6. At 2:45pm, set off to pick Mary up from school.
7. 3:40pmish: Return from the school run.
8. If it's a Monday or Wednesday: Finish work at 6:30pm, clean kitchen from lunch and everyone's breakfasts and snacks they've made themselves, make dinner, eat dinner, get Mary to bed; finish around 8:30-9pm.
9. If it's a Tuesday: Finish work at 6:15pm, take kids to Ju Jitsu, do shopping while they're there, take them home, then do the same as on Mondays except making a quicker (less nice) dinner and finishing at 9pm or later.
10. If it's a Thursday: finish work at 6:30pm, assess tiredness levels; if not too tired, head out to Cheltenham Hackspace, leaving Sarah and the kids to feed themselves, get home around 9:30pm.
11. If it's a Friday: finish work at 6:30pm, head out with Jean and her friend to run her Explorer Scout group, get home at 9:30pm.
12. In theory, to get eight hours' sleep, I need to be asleep around 10:30pm, so I try to go to bed at 9:30pmish; I'm often late to bed, and often can't sleep as my mind is brimming with thoughts and stresses.

Weekends involve Mary's dance class from 9am-11am on Saturdays and a climbing session for the kids on Sunday afternoon, and of course making lunch and dinner for us all, and between those two there's usually some mixture of:

1. Shopping, housework, that sort of stuff.
2. An event Sarah's involved in that I need to do some combination of drive her to/from, help out at, and look after the kids while she's busy.
3. An event the kids are involved in that requires them being taken to/from and possibly staying at.

In the gaps between the above and sleeping, I need to find time to:

• Have showers
• Do laundry
• Tidy the house and/or chase the kids to tidy
• Help kids with homework
• Do normal household admin (pay bills, renew insurance, organise MOTs, that sort of thing)

In practice, I think I get 2-3 afternoons off (defined as: there isn't something specific I need to be doing or somebody asking me to do something for them right then, so I can choose what I'm going to do) a month on average.

What I'd like to do:

• Work on my workshop: I have a fun plan to build myself an amazing custom desk/shelving setup that will give me space to store a lot of stuff that's in piles of boxes on the floor, and make this a more comfortable place to work in, and I need to finish building my workshop management system (12v power distribution for lighting, raspberry pi to monitor sensors and play music and make announcements with speakd and control the lights, etc).
• Do fun things with my family.
• Set up radio stuff and mess around with it.
• Work on the Snell-Pym Family Mainframe - including writing a long-overdue blog post about it!
• Work on my open source projects - I have great plans for Ugarit, and I'm rewriting my "Eye of Horus" system monitoring/alerting/metrics/observability system into something totally awesome.
• Practice Morse code and Lojban and welding and various other little things I'm trying to learn.
• Start doing Krav Maga again!
• Improve my resin-casting setup.
• Read more books.
• Visit friends and extended family.
• Write more blog posts.
• Write fiction.
• Work on my MMORPG game.

School holidays are great. Not having to do those two one-hour school runs every day gives me back ten hours a week alone, and the kids' clubs also stop, which adds up to another nine or so hours. Not having to wake up at 6:30am - I work from home so can get up at 8:30am - means I'm less tired to begin with, too, although it takes me a few weeks of not having to wake up at 6:30am before I stop automatically waking up at 6:30am!

However, when I get a free moment, I just feel... tired, and have no enthusiasm for anything. I tend to just slump in a chair and watch Youtube videos of people doing the things I'd like to do, until I run out of time. Unless I can awaken The Enthusiasm, I rarely have the energy to do much. This tends to leave me feeling guilty, as there's a lot of tasks on my TODO list that hang over me, and I feel I need to get them out of the way before I can work on "fun" stuff. Sometimes I have no choice; at the time of writing, my workbench in the workshop is taken up with a partly-built set of shelves for the living room, and I can't do much else until they're done and installed.

The guilt is a real pain. Logically, I know it's healthy to have some time off, and that resting and reading and passive media consumption and just chatting with my family is important for my self-care so should be the top thing on my TODO list after a few weeks of constant pressure - but I still feel guilt. Which depresses me and kills The Enthusiasm and makes the problem worse...

Usually, it takes me a week of no school runs and normal work, or two or three days off nothing, to get beyond that point and start to perk up. This means that, mainly, the school summer holiday is my best time.

Last summer, for the first week and a half I wasn't very productive; as before, I just sagged in my new-found free time. Enthusiasm for my projects started to pick up at that point, and I did some good work on the Eye of Horus, and started to have the energy for Morse practice again. I also had time to go for walks with Sarah and the kids a bit.

There's talk of school closures for a few weeks coming up to slow the spread of COVID-19; I will still be working as usual (I work from home) so it will be like a small summer holiday - which might be good for my TODO list, at least! But I suspect they'll be taken out of the normal summer holiday to prevent the kids' education from being affected in the long term... We'll see.

Update 2020-03-18 (2020-W12-03 for you ISO weekdate fans)

So, the schools aren't closed, but Sarah has a cough and a fever, and Mary has a cough, so under current guidance we're all to self-isolate for 14 days. I'm still working (I work from home anyway) so my weekday schedule now looks like this:

1. 8am: Alarm goes off
2. 9am: Get up, see if Sarah is OK and if she needs anything (she's isolated in a separate room).
3. 9:30am: Start work
4. Noon: Break for lunch, housework, sorting out things Sarah needs. Making lunch is a bit more involved than before, as we're trying to cook things from storecupboard food and ration out the "easy" stuff. Food is brought to Sarah and dirty plates collected after.
5. 2pm: Back to work
6. 6:30pm: Finish work, make dinner, eat dinner (again, take some to Sarah and bring it back later).
7. 9pm: Relax for a bit
8. 10pm: Bed

So I'm not getting much more relax-time in the week, but I am getting enough sleep, which is fantastic. I'm being a bit less productive at work, as I have a fair few interruptions from the family needing my help with stuff through the day and I'm distracting myself with worrying about stuff, but I'm still getting plenty done.

I've had one weekend so far - I mainly spent it being exhausted and not achieving much, as usual, but I'm quietly hopeful that will improve next weekend as I've been having enough sleep for a week!