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Air Con: $1697 for an on/off switch

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Re: Air Con: $1697 for an on/off switch

#391

Post by amiga-workbench »

Scoundreller wrote: post #354
amiga-workbench wrote: post #237

Earlier quoted context omitted.

That's where the wear levelling comes in, still expose 8GB of space to the host device, but internally have I dunno, twice that in cell capacity that you can move bits to as other cells wear out. Its a shame mobile devices don't have a SMART equivalent, would be nice to have some warning as something approaches the end of its life.

Do you even have to limit the exposed space? It’s not going to write at twice the rate just because more space is available.

You do, most SSD controllers already implement this. Have you ever wondered why most SSD's come in slightly odd sizes like 100GB instead of 128GB? The extra space is put aside and used for wear levelling and other maintenance tasks.

You can find out a bit more here https://www.seagate.com/gb/en/blog/ssd-over-provisioning-and...

I also remember a guide a while ago on how to reprogram a SSD to operate in SLC mode instead of MLC. You lost disk capacity but gained a large performance boost and a reduced error rate.

Re: Air Con: $1697 for an on/off switch

#392

Post by lgats »

paranoidrobot wrote: post #108

I installed AC in my home in the last year. I specifically went for units that were IR controlled rather than any proprietary smart B.S. For the smarts, I used cheap IR blasters from AliExpress and hooked them up to HomeAssistant. I just mounted cheap Lenovo tablets to the wall to do the room-dashboard thing to allow controlling lights/AC without a phone. These kind of horror stories only serve to reinforce my decisi…

I did the same, i recommend getting the moes or similar IR blaster (tyua under the plastic). Treat yourself and get a combo temp/humidity sensor + IR.

For one of the rooms i opted for a IR/RF transmitter and the RF covers any RF enabled devices in the house (433mhz + 315mhz[i think but haven’t tested])

Re: Air Con: $1697 for an on/off switch

#394

Post by e44858 »

paranoidrobot wrote: post #108

I installed AC in my home in the last year. I specifically went for units that were IR controlled rather than any proprietary smart B.S. For the smarts, I used cheap IR blasters from AliExpress and hooked them up to HomeAssistant. I just mounted cheap Lenovo tablets to the wall to do the room-dashboard thing to allow controlling lights/AC without a phone. These kind of horror stories only serve to reinforce my decisi…

Some units have a 5V UART port that's easy to connect to HomeAssistant and has two-way communication: https://static.xtremeownage.com/blog/2023/pioneer-mini-split...

Re: Air Con: $1697 for an on/off switch

#395

Post by cududa »

rocqua wrote: post #223
lawgimenez wrote: post #195

Earlier quoted context omitted.

They would have to put the condition inside shared library .so and use Android JNI. Make it complicated and hide the string tablet model throughout the code, just enough time to frustrate whoever is decompiling the so file.

If they want to really do it wrong (or right, from their PoV), they require the communication with the base station to be signed with a certificate signed by their root CA, and put the private key of that certificate in the TPM.

I genuinely get the sense nobody there is capable of coming up with this on their own and are likely looking at this thread for ideas

Re: Air Con: $1697 for an on/off switch

#396

Post by connicpu »

paranoidrobot wrote: post #108

I installed AC in my home in the last year. I specifically went for units that were IR controlled rather than any proprietary smart B.S. For the smarts, I used cheap IR blasters from AliExpress and hooked them up to HomeAssistant. I just mounted cheap Lenovo tablets to the wall to do the room-dashboard thing to allow controlling lights/AC without a phone. These kind of horror stories only serve to reinforce my decisi…

I also just got AC last year, and while it doesn't have as many fancy features I'm glad I got one that works with standard 24V HVAC wiring. I built my own thermostat out of an ESP8266, I²C temperature sensor from adafruit, and three TRIAC circuits to control the fan, heat, and ac wires. Connected to MQTT and I can send control commands to it from my Home Assistant instance!

Re: Air Con: $1697 for an on/off switch

#397

Post by FridayoLeary »

consteval wrote: post #347
yurishimo wrote: post #302

Earlier quoted context omitted.

Maybe they moved? In my experience, IKEA furniture that isn't solid wood (more and more of it is heading that direction to their credit) tends to not make it more than 1 move. I just got done (mostly) reassembling a wardrobe. It's a bit more wobbly around the edges. I'm not sure if it's because I didn't put the shelves back in the exact spots (wasn't thinking and didn't label them during disassembly) or if it's somet…

This "trend" of furniture being made of composite materials makes no sense to me. They're obviously so much weaker. I've had nightstands that sway like a tree in the summer breeze. Furniture today though doesn't feel much cheaper. Even the "luxury" brands these days, who charge big bucks, sneak in composite.

It does make the furniture much lighter and therefore easier to move. I once had to move a plywood dresser and it was an experience i'd rather not repeat. Light furniture on the other hand is a pleasure to work with.

Re: Air Con: $1697 for an on/off switch

#398

Post by Cerium »

JohnFen wrote: post #378
bitcharmer wrote: post #240

Earlier quoted context omitted.

I love it too but this only becomes worthwhile if you manage to promote this post in social media somewhere. If you don't already have a strong social media presence or don't personally know anyone who does you can forget about it. And here on HN you really have to get lucky, post at the right time and hope the flagging gangs don't get you.

I could not disagree more. This sort of thing is a public service. Even if only a dozen people find it valuable, it can be exceedingly valuable to them. It's worth putting this sort of thing on your website for that reason alone.

In complete agreement, I will add an anecdote from my experience:

I have a tiny hardly updated blog where I post stuff I do and assume nobody at all will ever read it. A month ago I got an email from somebody asking about a detail because her granddaughter's toy has the same problem that my daughter's did. It is so rewarding that some work I did for myself can continue to have value for people across the world.

Re: Air Con: $1697 for an on/off switch

#399

Post by cyberax »

liminalsunset wrote: post #226
cyberax wrote: post #98

Ugh. The whole "smart aircon" industry needs a good-sized asteroid wiping them out of the existence. There is a very real need for modern variable-speed units, and vendors just keep fucking it up by using proprietary protocols locked into their ecosystem. TRANE in the US is similar. And this is really annoying because variable-speed pumps solve all the problems with short cycling and oversized systems.

The problem with having standards for this kind of thing is that different units have different needs for communication and different levels of being smart. For example, some units want 2 temperature sensors and some want 3. The method used to control the system can be relatively complex - some systems are using physical models of the characteristics and positioning of sensors to do fancy control, and there are proba…

> The problem with having standards for this kind of thing is that different units have different needs for communication and different levels of being smart.

There really is nothing complicated there. I have some background in lift (elevator) systems, and they have similar requirements. Modern lift systems use variable frequency drives for smooth start/stop, and they came up with compatible protocols that allow users to mix-and-match controllers.

In the end, there just needs to be a simple protocol to command the motor to run at a certain speed. It can be CAN-based, it can be based on RS-485, etc. For additional smarts, throw in readings from the sensors inside the AC units (pressure, coils temperatures).

Then the control units can be made by third parties. They can do all kinds of prediction-based logic, complicated PID controllers, whatever.

> Some of these systems attempt to be "smart" and just use the 24V C/W/Y1/Y2 etc protocol as a "standards compliant fallback". You don't necessarily lose ALL of the smarts

You actually do with TRANE units. They become completely dumb, not even 2-stage emulation.

> The closest thing I can think of to a standard, and the way it is solved in larger buildings, is through something called BACnet.

I have BACnet at home, for wired temperature/humidity sensors, the same RS-485 network is also used for Somfy shades ( https://github.com/Cyberax/py-somfy-sdn ). BACnet is a low-level system, and it needs higher-level profiles. But yes, exposing the motors and the sensors inside the AC units over BACnet would be a great start.

Re: Air Con: $1697 for an on/off switch

#400

Post by agos »

kbouck wrote: post #323
XorNot wrote: post #56

Earlier quoted context omitted.

The nice thing about my Mitsubishi Heavy Industry units is I've got a bunch of MHI-AC-Ctrl[1] modules tucked into them talking to the service interface with Home Assistant. The neat thing is it doesn't just control it, it also makes all the internal sensors and codes available. What I think we really need to do though is make publishing these control standards mandatory under right-to-repair laws - no one should need…

Network-connected home Mitsubishi units can be controlled with the MELCloud API (same api used by mobile app) which makes it easy enough to write scripts that grab current temp, settings, power usage. Perhaps someone has already made a home assistant plugin that does this?

I keep thinking about doing this
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