Following on the heels of their Raspberry Pi 5 launch and some specifications for their RP1 all-in-one peripheral chip, the Raspberry Pi folks have now released an update to the HAT peripheral hardware specification reflecting the new model. Called the HAT+, it represents a major step forward with some significant changes.
Most visible will be changes to the mechanical specification, for while the original HAT specification was very rigid this new version is much looser. A HAT+ must only mate with the 40-pin connector, including the ID pins, and line up with only a single mounting hole compared to the four on the original. Electrically, a HAT+ must recognise the standby power state in which the 3.3-volt line is powered down while the 5-volt line remains active, while software-wise, there are changes to the content of the ID EEPROM including the ability to inform about stackable smaller HATs.
As the Arduino folks will no doubt tell you, the danger for the maintainers of a popular standard is that it risks becoming a victim of its own success, leaving it to ossify as it falls behind the cutting edge. For the Raspberry Pi, it must be a tight balance between keeping it up to date and not losing earlier models, and by our reckoning, they may just have achieved it.
We like how some have allowed multiple HATs, and we wonder if this will work — or will be made to work — with the HAT+. You usually think of HATs as having sensors or lights, but that isn’t always the case.
Too little too late imo. Not just for the HAT but for Raspberry Pi in general.
The inability to get one without having to be overcharged by scalpers or excessively scanning a list of stores in desperation has caused so many of us to just give up and move onto other SBCs which — while not a bad thing — sort of makes you wonder if there really is a point in going for a Raspberry anymore.
They’ve done nothing to address the issues in getting one’s hands on them either and they’re eye-wateringly expensive nowadays to boot.
The fact that you can get x64 sbc “mini PCs” that have similar power requirements and better supported hardware for double the price as well as handheld “gaming” emulator consoles that -are- the same price and include a case, battery, input and display (and now even have a very good community-maintained linux distro to boot) makes the Raspberry Pi 5 already look decrepit if not outright pathetic in comparison.
What gaming consoles are you referring to? I don’t follow them, but that sounds interesting.
JustEnoughLinuxOS @ github has a big ol’ list.
Not at GitHub at there own website
https://jelos.org/devices/
Have you tried buying from anyone besides Amazon and eBay? They’re out there, albeit with significant quantity restrictions.
Availability is not a problem at the moment. You can buy Raspberry Pi 5s from Digi-Key, they’re in stock. Mouser probably has them as well. Pi 4s are even easier to find, I just bought 12.
DigiKey doesn’t have any RPi5 8GB in stock.
Availability of the older Pi models has never been that bad, and the current ones are in stock at every retailer I’ve ever used right now… And blaming them for being hard to get or scapled when everyone was struggling with those problems in the aftermath of Covid is rather silly, for a relatively small electronics manufacturer they dealt with those problems rather impressively.
Price wise the Pi5 seems really darn competitive to me – yes its expensive compared to the lower numbered Pi’s but its got performance and exciting potential with PCIe and that 2040like chip built in to go with it – and considering inflation the launch price of a new Pi5 isn’t actually that much more than the older models, and they were not nearly as close to the same performance relative to the average PC of their era. If cheap was the only thing that mattered you can still get a Pi2 or something if you want to. Not going to be getting great value for money doing that, but there is nothing wrong with a Pi2 if cheap low power computer was your goal.
The few other SBC that might on paper match or better a Pi tend to be saddled with such terrible support you are stuck running an obsolete kernel for the rest of time and with only half the onboard hardware actually functional… Potential is definitely there in some other boards, but the reason Pis remain in huge demand that stretches supply a bit despite every growing production numbers is because they are so good and well supported they actually meet or even exceed the expected potential of the hardware on paper…
Yes there are finally some consumer available x86-64 options that actually have performance and efficiency enough to perform well at a low power budget, but they are pretty much only available in devices that generally cost massively more than a high end Pi, yes you get some fluff that might be useful with these devices but its not at all the same thing. One is something that is probably a rather bare minimum PC with limited options – GPIO probably none, flexibility to put into your own project limited, documentation beyond the most basic user guides probably none-existent, the ability to actually get a spare for when you do manage to break something in your project very much more limited – maybe you can for a year or two but long term… You can still get old model Pi for drop in replacements and the Pi folks promise a prolonged period of being able to do so on their products.
If all you want is a finished Steamdeck or GPD Win type device to play your retro games on or whatever you are clearly not looking at the right thing in a Pi, if you actually want a performant, flexible and easy to embed in your project computer you are almost certainly looking at the wrong thing if you at any of the completed devices…
Never been bad? Are you kidding me?
There were literal watch lists and discord servers you could join that would announce you when there would be stock. Please don’t kid yourself.
It’s a nice change, it never made sense to have an expansion “bus” that allowed only one device. One has to be careful with which HATs can be combined but plenty can, and the hardware community is plenty capable of figuring it out.
That said, in this age of power hungry Pi’s that need coolers to reach their potential, putting other hardware on top becomes a bit problematic. Hardware below the Pi would be a whole lot more practical than on top, or alternatively to not break compatibility, the CPU should be on the bottom so it can be cooled from that side.
Sorry but we are not in an age of power hungry Pis. Quite contrary. Pis are more efficient than ever! Run your Pi 5 with clock&voltage lowered so it has the same performance available as Pi 3 and you’ll see that it runs much cooler than Pi 3 ever ran both under max load and in idle.
What has happened to reading comprehension? Didn’t I say “need coolers to reach their potential”?
Sure, you can run them slower but most people are not going to do that. They’re going to slap a cooler on it and once that’s there you need a riser to even fit a HAT and the HAT will be in the way of some of the airflow.
My point is that the HAT idea worked better during the time that cooling a Pi CPU was not a concern anyone had, now it’s less than ideal.
But sure slow down your Pi if that makes you happy.
He said to set the 5 to the same clocks and voltage as a 3 and compare the thermals, to show the 5 is a more power efficient device. He did NOT say run it like that all the time.
That said, what’s wrong with clocking it down if you need the feature set but also need to meet a specific power budget, for example off-grid.
Potential can mean a lot more than just performance.
Says “need coolers to reach their potential, putting other hardware on top becomes a bit problematic”
Well, not really as all you have to do is add a pin extender to the 40 pin connector and use taller stand-offs. Or use a ribbon cable as there are boards that move that hats to another extender board where you can put multiple hats (I have a couple that I’ve bought ). So not a problem at all.
The ‘power hungry’ question was answered above. It can be as power hungry as it ‘needs’ to be … or not. So depends how the user plans to use the board. Very flexible.
Boy, sure would like to edit :) . “Use a ribbon cable from the RPI header to an extender board that can accommodate multiple hats”. zzzzzz.
I too thing it is a nice change to HAT+. See how it goes.
But then you’ve radically increased the size of the whole thing. Putting the CPU on the bottom is a much better solution.
Personally I think CPU on the bottom adds more hassle to a normal format Pi than it is worth – breaks the whole ecosystem of existing Pi mounting hardware and accessories design. I’d also suggest heat sink on the bottom doesn’t actually end up smaller – that heatsink only works if its got airflow or a good heat conductive surface to sit on, which means it has to be really quite huge if its to sit on the bottom and actually function while sitting on the average desk – and it will be that way in nearly all cases as the user input HAT are on the top! A little bit of taller GPIO header and standoffs to fit a larger cooler underneath probably cools better and works out smaller as that cooler has better access to the air, and with no extra space at all and the thin heatsink that implies I’d suggest you may well get similar performance – even sandwiched between HAT and Pi that heatsink is probably more able to radiate heat (including through the HAT) than a compact heatsink (to keep the total size similar) on the bottom.
For the users that need extra compact and superb cooling the compute module is and always will be the right Pi for the job (even if CM5 isn’t out yet a CM4 is no slouch) – you can then have that extra compact package, the I/O exactly where you want it, the heat sources positioned where you want them.
“Radically increase the size”. Agree with the ribbon cable solution.
But the last few projects I did, the RPI-4s were relatively swimming in extra space around them. I agree though, if looking at say a hand held device where small as possibly is the game… Wouldn’t be practical.
Oh forgot there is also the split connector where pins continue up and also have a set at 90 degrees.
I always wanted to design and market an Audio Sink-Source hat but they rarely play nicely and just rub people up the wrong way…
But what color does the Hat have? Black, White, Grey? This is important!
HATs kind of suck compared to a bus. I wish RPi would have approached the expansion in a way somewhat like Risc PC’s slices. Where you can stack peripherals on top of a shared bus. Part of the problem is the microcontroller-like heart of most SoCs has a lot of built-in hardware interfaces that can’t be shared easily. Unlike old-school things like SCSI, or somewhat modern interfaces like I2C.
Normally I’d say that hindsight is 20/20. But even a cursory examination of computing history would have informed the RPi Foundation how to build an enduring platform.