dgriffith

joined 2 years ago
[–] dgriffith@aussie.zone 7 points 23 hours ago (4 children)

Australia and NZ have country wide coverage for SMS via starlink.

Australia is a huge landmass , and being able to send/receive messages just by having a view of the sky is quite significant for emergency situations.

Here is a map showing phone coverage in Australia from all providers. There's about 5 million square kilometres with no service at all, that now has basic communications via starlink.

Mobile phone coverage in Australia

[–] dgriffith@aussie.zone 121 points 1 day ago* (last edited 1 day ago) (6 children)

You can ship 1 ton/1m3 of cargo via any international air freight company to the other side of the world for less than 10,000 dollars.

(Source: I've done it plenty of times)

A day for pickup and transport to the airport in Sydney, 24 hours for actual transit, a day in customs in LA, a day for a truck to deliver it to that location. 5 business days to get that IBC to your destination in LA, tops.

[–] dgriffith@aussie.zone 5 points 1 day ago* (last edited 1 day ago)

Slow charge/discharge rates, cycle efficiency (in vs. out) is much lower than lithium, much heavier and bigger for the same capacity, liquid electrolyte to spill, generates hydrogen gas when charging.

Basically, it's the wrong battery for this kind of application. Great for a house battery charged off a lot of solar that you want to keep for 50 years. Not so great for a scooter.

[–] dgriffith@aussie.zone 5 points 5 days ago* (last edited 5 days ago) (1 children)

Qualcomm has its "IZat" system where:

- every AP's BSSID your phone sees is sniffed by a program running continuously in the background, mapped to a latitude/longitude if possible (via GPS or any phone location means) and sent to their servers,

- So that other devices can send a list of AP BSSIDs and signal strengths and get a triangulated location within 5-10 meters.

So the server ends up with a global database of AP locations, and also the location of every device in the world using the service within ~5-10 meters.

They've had this in action since 2012.

[–] dgriffith@aussie.zone 3 points 6 days ago

Owned by Akami now for 4 years, I think.

I've several small linodes and have been using the platform since 2018 or so. No difference seen so far in the linode plans or features I'm using with Akami, except for more in-depth monitoring available (for a price).

[–] dgriffith@aussie.zone 6 points 1 week ago

Now if you turn anything off (like that stupid autobrake that brakes for cars in the left hand turn lane beside me), they’ll use that to say “it’s not our fault, the driver turned it off!”

Don't try and spin this as a convenient liability-limiter for manufacturers.

Unless it is an actual failure of a safety critical system, with no warning, that then directly leads to harm, manufacturers are in no way responsible for how you operate the chunk of metal and technology that you bought from them.

All this stuff absolutely helps to reduce the overall risk of injury when operating a vehicle. Is it also a pain in the ass sometimes? Sure it is. Can you turn it off? Sure you can. But sometimes that shutoff is just temporary, because governments - not manufacturers - mandate that some things are now required, because they're sick of hosing body parts off of highways.

[–] dgriffith@aussie.zone 8 points 1 week ago
[–] dgriffith@aussie.zone 9 points 1 week ago* (last edited 1 week ago) (2 children)

LLMs looove to commit things. Every little thing. It is handy for them as they can use commits as their own memory store that they can scan easily, but it leads to very wordy-but-minor commits.

Things that humans would just lump together in a single commit like "updated docs" gets broken into commits for every single change made over the course of a few hour session.

[–] dgriffith@aussie.zone 5 points 1 week ago

This is not like the days of old where television/radio/newspapers pushed their opinions to the public en masse. It's social media, where everything is tailored to you, personally, available to you on your personal device that you carry with you everywhere 24/7, and it makes it so much harder to resist it.

That couldn't happen with the mass media of old. It wasn't tailored for you, so there were enough rough edges that you could stop and say "Hey, this guy's an asshole!" and break the loop. It wasn't with you all the time , sneaking in during that 30 second scroll of your phone when you're bored.

Now, it's continuous reinforcement where a tiny aspect of your profile matches a tiny part of their message, so you see it in your feed, and then it slowly cycles you through more and more of what they want you to see, until your interests match their interests and their opinions seem normal, because you see them all the time.

Brainwashing, essentially. And it's very hard to get yourself out of it.

[–] dgriffith@aussie.zone 18 points 1 week ago* (last edited 1 week ago) (2 children)

I don't know what they used on the moon landing, though.

An efficient, real-time multitasking software stack on a 2MHz processor with the equivalent of ~4K of RAM and 64K of ROM.

Smart enough to handle being accidentally overloaded by its operators and still balance a spacecraft on a single engine and land on the moon while doing multiple reboots to clear its software stack. It would work its way down a list of "fly a spacecraft" tasks from critical, to informational, to just monitoring, with a certain amount of time allocated to complete the whole list. If it ran out of time, it would drop everything, perform the equivalent of a reboot with navigation parameters parked in memory, and then start again at the most critical task.

Apollo 11's crew accidentally left their rendezvous radar (which was checking on the location of the command module in orbit) in a mode that constantly poked the computer with "pay attention to me" interrupts, and it couldn't service the radar and run through it's task list completely while it was on descent to the lunar surface.

To the programming team's credit, this just caused an overload alarm a few times and the mission completed successfully.

The Apollo programmers pretty much created the whole software engineering field from scratch in the 10 years before 1969.

[–] dgriffith@aussie.zone 44 points 1 week ago (7 children)

At this point, I'm just hoping that when we are sifting through the smoking wreckage of the AI crash we'll find a hundred million books that we can add to Anna's Archive.

And some RAM. RAM would be nice.

[–] dgriffith@aussie.zone 2 points 1 week ago (6 children)

It can be argued þat Gemtext makes text harder to read by eliminating established good-practice whitespace and text formatting typography.

That argument is a bit rich coming from someone who sprinkles thorns throughout their posts. 👀

 

Hi all,

In an effort to liven up this community, I'll post this project I'm working on.

I'm building a solar hot water controller for my house. The collector is on the roof of a three-storey building, it is linked to a storage tank on the ground floor. A circulating pump passes water from the tank to the collectors and back again when a temperature sensor on the outlet of the collector registers a warm enough temperature.

The current controller does not understand that there is 15 metres of copper piping to pump water through and cycles the circulating pump in short bursts, resulting in the hot water at the collector cooling considerably by the time it reaches the tank (even though the pipes are insulated). The goal of my project is to read the sensor and drive the pump in a way to minimise these heat losses. Basically instead of trying to maintain a consistent collector output temp with slow constant pulsed operation of the pump, I'll first try pumping the entire volume of moderately hot water from the top half of the collector in one go back to the tank and then waiting until the temperature rises again.

I am using an Adafruit PyPortal Titano as the controller, running circuitpython. For I/O I am using a generic ebay PCF8591 board, which provides 4 analog input and a single analog output over an I2C bus. This is inserted into a motherboard that provides pullup resistors for the analog inputs and an optocoupled zero crossing SCR driver + SCR to drive the (thankfully low power) circulating pump. Board design is my own, design is rather critical as mains supply in my country is 240V.

The original sensors are simple NTC thermistors, one at the bottom of the tank, and one at the top of the collector. I have also added 4 other Dallas 1-wire sensors to measure temperatures at the top of tank, ambient, tank inlet and collector pump inlet which is 1/3rd of the way up the tank. I have a duplicate of the onewire sensors already on the hot water tank using a different adafruit board and circuitpython. Their readings are currently uploaded to my own IOT server and I can plot the current system's performance, and I intend to do the same thing with this board.

The current performance is fairly dismal, a very small bump of perhaps 0.5 - 1 deg C in the normally 55 degree C tank temperature around 12pm to 1pm, and this is in Australia in hot spring weather of 28-32 degrees C.(There's some inaccuracy of the tank temperatures, the sensors aren't really bonded to the tank in any meaningful way, so tank temp is probably a little warmer than this. But I'm looking for relative temperature increases anyway)

Right now , the hardware is all together and functional, and is driving a 13W LED downlight as a test, and I can read the onewire temp sensors, read an analog voltage on the PCF8591 board (which will go to the NTC sensors), and I'm pulsing the pump output proportionally from 0-100 percent drive on a 30 second duty cycle, so that a pump drive function can simply say "run the pump at 70 percent" and you'll get 21 seconds on, 9 seconds off. Duty cycle time is adjustable, so I might lower it a bit to 15 or 10 seconds.

The next step is to try it on the circulating pump (which is quite an inductive load, even if it is only 20 watts), and start working on an algorithm that reads the sensors and maximises water temperature back to the tank. There are a few safety features that I'll put in there, such as a "fault mode" to drive the pump at a fixed rate if there is a sensor failure, and a "night cool" mode if the hot water tank is severely over temperature to circulate hot water to the collector at night to cool it. There are the usual overtemp/overpressure relief valves in the system already.

All this is going in a case with a clear hinged cover on the front so I can open it and poke the Titano's touchscreen to do some things.

Right now I am away from home from work, so my replies might be a bit sporadic, but I'll try to get back to any questions soon-ish.

A few photos for your viewing pleasure:

The I/O and mainboard plus a 5V power supply mounted up:

The front of the panel, showing the Pyportal:

Thingsboard display showing readings from the current system:

Mainboard PCB design and construction via EasyEDA:

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