Minisplit AC units are not very popular in the US. The US mainly uses either central air conditioning units or all in one AC units that are designed to be installed in a window. The window units are cheap, but inefficient. The central units are more efficient, but very expensive. Minisplit units are more expensive than window units (by probably a factor of 10), but are more efficient than either. I suspect most people in the US do not know that minisplit units are even an option.
In my home, I recently had a heat pump unit replace my central A/C with some minisplits that connected to the exterior unit installed in the basement. The entire setup cost as much as it originally cost to install the central A/C, despite parts of the central A/C being reused.
Note that in the US, what we call air conditioners only support cooling and not heating. When they support both, we call them heat pumps despite that being the scientific name which applies to the cooling only units too.
I don't think it's just "most Americans don't know."
When I installed AC in my former Bay Area home, I would have needed multiple mini split units to cover 1200sq ft, with questions about how many you could have on at once to still get the right performance. I went with a single central air unit instead.
It also (at the time at least) didn't come with a centralized thermostat, which meant managing each room individually (that would've been fine with me, personally, but it's a drawback for lots of people).
On top of that, many (if not most) mini split units are also somewhat aesthetically displeasing.
In my new home (on a different continent), I have mini splits. I'm somewhat satisfied with them, at best. I'd still prefer central air but it's not a thing for residential homes here.
If I were to ask most people I know offline, I suspect only a small number of them would know what a minisplit unit is. For most people, A/C is like plumbing. They do not think about it until it breaks. Learning that there are better options is just not something that people do.
That said, I was replying to someone from Vietnam. Assuming that things in Vietnam are similar to China and Japan, people will only heat or cool the specific rooms that they are using, rather than heating or cooling everything like how many Americans do things. Those in the US who cannot afford to heat or cool everything, who are likely very underrepresented here, would be those using window units, since they are cheap upfront. A minisplit would be cheaper over the long term, but the high upfront cost dissuades people in thing market from even looking at them.
Finally, I had Fujitsu minisplit units installed in my basement two years ago. They are far more aesthetically pleasing than window A/C units.
How long of a long term are we talking about? I suspect this is very dependent on many factors (not least of which is labor, but also insulation, climate, etc).
The energy (gas+electric) bill for my whole home would've taken well over a decade to add up the amount the mini split installation alone would've cost, so even if it brought down my energy cost to zero (which it wouldn't), it would've taken a decade to pay for itself (including the cost of window units).
Edit: and yes, they're prettier than window units for sure, but as you've pointed out, they're not competing with window units. They're competing with ducted central air that has almost no visible impact.
If you need R410A refrigerant, the high costs are due to government regulations causing the shortage. I very much hope that the heat pump I had installed 2 years ago does not leak. Theoretically, if the leak occurs under warranty, it should be covered. The central A/C unit I replaced with the heat pump had developed a leak right before the warranty expired, which resulted in a costly repair being covered. Unfortunately, we paid another company to refill it before learning that it would be covered as part of the warranty repair by the company that installed it. It then developed a second leak several years later, so I had a heat pump installed. Of course, that heat pump uses R410A refrigerant.
The leaky A/C unit had been made by Lennox while the new heat pump was made by Fujitsu. I very much hope that Fujitsu engineered its heat pump to last. The heat pump had also replaced an oil heating system that was around 25 years old and still could have been used for many more years. Expecting similar or better longevity out of a heat pump does not seem unreasonable.
> If you live in the United States today, and you accidentally knock a hole in your wall, it’s probably cheaper to buy a flatscreen TV and stick it in front of the hole, compared to hiring a handyman to fix your drywall.
While this is true, the costs are inflated because you need to repaint the entire room to get the original look, rather than only pay the cost of merely replacing the drywall. Of course, some handymen are much more expensive than others, so it is possible that is more expensive too.
If you are one of the few using wallpaper and have extra wallpaper for just such emergencies, using the extra wallpaper to paper over it should be cheap.
> On the spiritual side, I think it is somewhat calming. I face this at times when you have patients that pass away and you talk their families; you have to be the bearer of bad news. Right now, we don't know anything about what happens to their loved one’s brain when they're dying. I think if we know that there is something happening in their brain, that they are remembering nice moments, we can tell these families and it builds a feeling of warmth that in that moment when they are falling, this can help a little bit to catch them.
I do not see any connection between this and spirituality. I also see no reason to think that they must be remembering nice moments. It is possible to be remembering painful moments. This seems especially likely in cases of PTSD.
That might be an excellent reason not to use some of these capabilities. And maybe in a different situation it would make sense to use the mechanisms provided. Programmer’s responsibility to decide what’s appropriate in each case, that’s all I’m saying.
There is no statement about the efficiency of the motor itself. If the energy conversion efficiency is low, then the weight savings will not matter and the car will have even less range.
This depends on the PIO in the RP2040/RP2350. As far as I know, that is an innovation exclusive to the Raspberry Pi company, so it would not be possible to do this on another microcontroller:
The microcontroller has additional cores called state machines in the PIOs that are specifically designed for bit banging and have their own custom ISA that reportedly only has 9 instructions.
Yes, it does, although it's almost like horizontal microcode; it can do several things in a clock cycle other than the instruction itself. I didn't mean to imply that you could bitbang 100BaseT with a Padauk PFS150 or a PY32.
The Padauk FPPA chips are probably a bit better at bitbanging strange protocols than any ARM, but not in the same class as the Pi's PIO.
After consulting the datasheet, I think the most things you can do in a single pioasm instruction would be a conditional decrementing JMP with side-set, wrap, and delay:
• decrement the X or Y register;
• conditionally jump to a specified target address if it was nonzero;
• otherwise, jump (by "wrapping") to some other specified target address, usually an outer infinite loop;
• change the state of four or less GPIO pins to immediate constants;
• delay 1–15 clock cycles.
Arguably IN can compete here, replacing the first two items with:
• set one or more GPIO pins from bits shifted out of a shift register;
• conditionally "autopull" a 32-bit word from an input FIFO if the shift register is empty;
• conditionally stall the pioasm program if the FIFO is empty;
• conditionally initiate a DMA request to refill the FIFO if it's not full.
The OUT instruction has similar "autopush" capabilities.
Most of these are somewhat independent choices, but if you don't pull from the FIFO you won't have the other effects, and several of the options are state-machine-wide.
This would be a great starting point to make a USB Ethernet NIC if someone were inclined to do it.
It could even have a very practical use if it were made to impersonate a USB Ethernet device that the Nintendo Switch / Nintendo Switch 2 supports. They only support gigabit NICs, but it should be easy to just pretend that the other side failed to negotiate gigabit and only supports 100Mbps.
I remember hearing about people doing that around the time that windows 98 was still current. It was really impressive.
At the time, the idea of an operating system using a gigabyte of space was a fantasy to most people. Now, I wonder when Microsoft Windows will pass the terabyte threshold.
In my home, I recently had a heat pump unit replace my central A/C with some minisplits that connected to the exterior unit installed in the basement. The entire setup cost as much as it originally cost to install the central A/C, despite parts of the central A/C being reused.
Note that in the US, what we call air conditioners only support cooling and not heating. When they support both, we call them heat pumps despite that being the scientific name which applies to the cooling only units too.