Bit rot in micro controllers? (2023 Update)

Our clothes washer got erratic so I replaced the mechanical timer, the thing with a drum and a zillion cam switches. It was easy, after the youtube tutorial.

+1

I've several old boxen that still run (Compaq Portable 2, Portable 386, SPARCstation Voyager, even a "Megaboard" from CP/M days, etc.). IME, the issues that limit lifespan are:

- bad batteries in NVRAMs (or, batteries that fail and are too hard to source)

- bad caps in power supplies (sooner or later!)

- mechanisms that dry out from lack of use (floppies)

Of course, I image every programmable device in this sort of kit so I can always refabricate if a problem develops, there. So far, the only need has been to manually edit the disk parameter tables to define larger drive "types" (cuz finding < 1GB disks is hard!)

I suffered an outage not that long ago that lasted 36 hours, or so. People in the nearby suburb were without power for a week.

This was after a severe storm that brought down power poles and cables.

Such things don't happen often, but when they do, being needlessly without the ability to cook things is really annoying.

Sylvia.

Now that I've lived in various places in Puerto Rico I have a better appreciation of what happened after Maria. The island is only 100 miles by 35 miles, but the entire central portion of the island is mountainous with homes only along the various roads. Everything is on poles. If *all* of the wires and poles are destroyed it takes a long time for them to be replaced everywhere. I've talked to people who were within the greater San Juan area who had no power for months. Other regions had no power and no water. People lived by using generators and hauling gasoline and water. Even food was hard to find for a while.

The problem was not the people. The problem was no longer having infrastructure. Makes it hard to get anything done. Add in a total lack of support from the Federal Government and it results in a slow recovery.

1. Yes it's possible. High temperatures will speed it up (that's how they test retention).
2. Remedy? Get a spare board, design one (not worth it financially) or replace the appliance. The memory will be locked to prevent it from being read (easily).
3. Make *sure* you're not seeing a side effect of a failing power supply. Power supply ripple from failing (high ESR) e-caps would be my very first suspicion in a device that old that operates at elevated temperatures.

Jones Act doesn't help either, from what I've heard.

Design a new controller with relays.

A bag of charcoal stored in a water-tight container (I use the

5G paint containers leftover from roof painting) will address that easily.

Or, having a tank of propane (for gas grill) on hand.

Or, a small bottle of propane (think: plumber's torch) and a single-burner, portable "camp stove".

Or, genset that can deliver ~2KW (the load for a single stovetop burner, on HIGH).

[dual-fuel giving you some flexibility, there]

As our utilities are below grade, outages from storms, drunk drivers, falling tree limbs, etc. are pretty rare. However, the infrastructure is approaching its design life and many of the buried coaxial cables are failing.

As pad-mounted transformers are daisy-chained with these, an outage only affects the homes downstream from the fault. And, as each "branch" can be fed from either "end", the remedy simply involves isolating the failed cable segment and connecting the "spare" cable to the other feed end (to power those isolated homes until a new cable segment can be installed).

By far, the more concerning "outage" is loss of natural gas supply. This happened a few years ago (demand far exceeded the ability of the pipeline to deliver) and much of the city was deliberately cut off from the supply so the rest of the city had sufficient pressure and flow to satisfy the needs of gas appliances (mainly, gas-fired heating). It was annoying to see the furnace ignite... then shut itself down, moments later, as it wasn't generating enough heat to convince the sensors that gas was actually flowing! (Lather, rinse, repeat)

Most folks can't easily heat a home in the absence of that source (but the need for heat, here, is only token).

Loss of domestic/potable water would probably be a panic issue! (but, we have wells all over town so it would need to be a city-wide power outage to disable ALL pumping stations)

Blech. I have a water heater that uses electronics to start the pilot when you first turn the gas on, but also has a bimetallic safety valve.

Why would one want a gas oven, period? All that water vapour makes pastry tough. Electric ovens, gas cooktops are the ticket.

Round here we need a generator to run the circulation pumps on the gas boiler (which uses the millivolt system).

Cheers

Phil Hobbs

You don't have actual weather, though. We get Atlantic hurricanes. We had an outage 5 or so years ago that lasted (iirc) 8 days.

I got on the Con Edison website, and mentally divided the number of affected customers by the number being restored per hour, and got a number like 10 days.

There were no generators to be had locally by then, so I got a 5 kW one from Amazon and hired an electrician to put in a transfer switch and an external feed inlet. I had power by day 3, but it cost about $1500 all told. (Plus now I have to mess around with gas stabilizer and battery tenders.)

Cheers

Phil Hobbs

put the cables under ground ;)

get hybrid car, some of them have a pretty beefy inverter that runs off the main ~400V battery ;)

People in Puerto Rico cite the Jones act of causing all sorts of mayhem. I think it is over rated. I've yet to hear from anyone who could cite even one example of significant impact of the Jones act. In this case, it would seem to be possibly misunderstood.

"The Jones Act requires goods shipped between U.S. ports to be transported on ships that are built, owned, and operated by United States citizens or permanent residents"

So while the cartoon may be accurately showing a foreign *ship* not being allowed to bring supplies from another US port, it would not prevent the import of supplies from a foreign port on any vessel.

The people in Puerto Rico do seem to have a certain level of resignation to many political impacts on their lives. They don't have a two party system in Puerto Rico, but people complain that none of the parties are actually any more effective than the others!

Do we have an equivalent law to protect US airlines or US ground shipping? How about US bicycle couriers and pizza delivery?

That doesn't sound encouraging :-(

Either I'll try to find a new controller or turn all that stuff towards analog. The new controllers are unfortunately for 1rpm augers while the older stoves have 4rpm augers. So I'd have to follow the auger motor control output with some sort of nifty "adaptable pulse length corrector".

Yes! Or better yet, design an analog controller that works like it used to be on pellet stoves.

Charcoal? That's only for wimps :-)

I cook over manzanita or almond wood, depending on the meat for that particular meal. When the power went for the first time around here (the famous Californian Gray-outs) my wife almost panicked because she had just started cooking an elaborate gourmet dinner. I fired up the barbie and then we had everything we wanted. Steaks, freshly baked bread, baked potatoes with sour cream, whiskey peppercorn sauce, steamed vegetables, followed by some sort of glazed dessert and, of course, espresso.

No way.

Ok, but then I'd rather use a few rocks and a few pieces of wire to hold a pot over the fire.

Glamping :-)

Much of California has among the highest electricity prices but a grid reliability like Romania in the 80's.

[...]

During an outage I called a store for something else and before the clerk that picked up the phone even said her name she proclaimed "We do not have any generators in stock".

That monster must consume gasoline to no end. I bought a 1700W/2000W inverter generator. It suffices to drive the big kitchen fridge/freezer and a small chest freezer downstairs. Plus the swamp cooler and a few little items such as lights or a TV set. It modulates the engine RPM according to load, spends much of its time in mid-idle and can run aboyut four hours on a galloin of gasoline.

I use the stabilizer for storage purposes that is supposed to last two years. I also start the generator about once a month, to make sure the carburetor doesn't gunk up and to have peace of mind that it will start if needed.

[...]

Nah, a wood fire is the ticket. That's how I also bake pizza, rolls and bread. The real bread, German style with a crust that requires good chompers. Our house has an indoor cooking alcove for woord/charcoal cooking but I always do it outdoors. Rain or shine. Less messy, more manly :-)

[...]

Try burning a stump out of the ground with "a pile of wood".

Running a genset on wood is pretty tough...

We (our house) have been caught downstream of two cable-segment faults. I believe there is one that hasn't yet failed between us and our nominal feed direction. Once that has failed and been replaced, we should be set for another 20+ years...

[An amusing feeling to see homes "two doors down" with power while you sit in the dark. But, the outages are never long enough to warrant firing up the genset; the UPSs carry most of the important loads...]

Other (older) parts of town still have flying power/phone distribution. I suspect they suffer more outages from the increased vulnerability of that distribution method.

But then when water gets in, you're out for weeks and weeks. No thanks. During Hurricane Floyd, we got over 60 cm of rain in a day, plus a number of washed-out roads. That will reliably do a job on underground mains.

A dozen years later we had Hurricane Irene, which was smaller, but in my nabe was even worse because it washed out a short section of road that also had electric, gas, and water mains.

The networks were well-designed, so most of the supply was restored quickly, but fixing the damage took a couple of months.

As I said, you folks don't have real weather.

What I actually did was to get a generic electric gas pump and some

5/8-inch tube, so that I can pump gas directly from my car to the genny, and then pump it back once power is restored.

Cheers

Phil Hobbs