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HawaiianPi
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Re: I didn't think the usb c power thing was a big deal...

Fri Jul 12, 2019 7:25 pm

Fraoch wrote:
Fri Jul 12, 2019 7:00 pm
I haven't tried the official 2.5 A power supply with the adapter, but I would be surprised if that didn't work fine as well.
It works, even when hybrid booting from SD with the OS on a USB 3.0 SSD. There were no official Pi4 power supplies available when I ordered mine, and I already owned an official 2.5A Pi3 PSU and some Volutz micro USB to USB-C adapters, so that's what I'm using now.

Since pure USB boot is not enabled with the current firmware, I have /boot on a micro SD card and / (root filesystem) on a SATA-III SSD with a USB 3.0 to SATA-III adapter cable. Here's a picture of a similar setup on my Pi3. Same configuration for my Pi 4B, and it works fine using the old 2.5A power supply with this adapter. I'll get the official USB-C PSU eventually, but for now this works for me.
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Fraoch
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Re: I didn't think the usb c power thing was a big deal...

Fri Jul 12, 2019 7:39 pm

Yup, typing this on my 4 right now with the official 2.5 A micro USB power supply with my micro USB - USB-C adaptor and it's working perfectly. I wouldn't even know I had done it.

Also noticing the power supply is just barely warmer than ambient, so it's nowhere near stressed.
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HawaiianPi
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Re: I didn't think the usb c power thing was a big deal...

Fri Jul 12, 2019 7:53 pm

Fraoch wrote:
Fri Jul 12, 2019 7:39 pm
Also noticing the power supply is just barely warmer than ambient, so it's nowhere near stressed.
I should try my system on my RAVPower charger with a USB power meter. While I am one who often advises against the use of chargers as power supplies (due to poor voltage regulation on many), I have load tested my RAVPower PC002 chargers, and since they use a separate micro USB cable, it's easy to insert a USB power meter into the chain.

With 3A rated Volutz micro USB cables and USB-C adapters I could get some PSU side load figures under various conditions.

Still a bit busy with personal crap, but I'll try and remember to do that when I have time.
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Re: I didn't think the usb c power thing was a big deal...

Fri Jul 12, 2019 8:56 pm

HawaiianPi wrote:
Fri Jul 12, 2019 5:19 pm
hippy wrote:
Fri Jul 12, 2019 5:04 pm
The term "charger" is often only a lingering legacy term when used with top-end power supplies. It has almost become a colloquial term for whatever connects between the mains and the device, which just happens to power the device and charge its battery.
Nobody calls an ATX power supply a charger.
Probably not but I don't think that's really relevant. And maybe they would if the ATX supply wasn't fitted inside the PC case was external, like a laptop power supply or charger, and especially if the PC had internal battery backup.
HawaiianPi wrote:
Fri Jul 12, 2019 5:19 pm
If it's designed to charge a battery, it's a charger, and may get away with poor voltage regulation. Doesn't matter if it can also be used to power the device while charging (the battery is what powers the device, and also acts as a rudimentary UPS).
By that argument it means laptop mains power supplies aren't; they are chargers.

And I don't believe it is the battery powering the device whilst charging. Simple current flow would seem to suggest it isn't. And that wouldn't work when one had removed the battery and were only running it from the power supply charger. I do that all the time with laptops and tablets I've rescued from landfill.

Whilst some chargers may not be power supplies, that some power supplies may get called chargers doesn't meant they aren't power supplies.

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davidcoton
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Re: I didn't think the usb c power thing was a big deal...

Fri Jul 12, 2019 9:17 pm

hippy wrote:
Fri Jul 12, 2019 8:56 pm
Whilst some chargers may not be power supplies
Sorry, but that is just plain wrong :twisted:
Every charger that works supplies power. Therefore, it is a power supply. Any power supply, whether it is a charger or not, may or may not be good at its primary purpose. It also may or may not work at any other power supply task. We need to move away from semantics and emphasise that power supplies for Pi computers MUST be able to supply the necessary current (required by Pi and peripherals, not the same thing as the supply's current specification) without dropping the output voltage below the USB minimum requirement of 4V75.

The fact remains that the power supplies intended to supply a charging circuit often have poor voltage regulation and cannot maintain 4V75 at anything like full load. Hence, the standard, correct advice is to use an appropriate version of the "official" PSU whenever there is doubt about the quality of the power supply.


BTW, most USB "chargers" are no such thing -- they lack the regulation and protection circuits required to charge a particular battery or cell. The modern charging circuit is usually more associated with the battery or cell than the power supply. Track the development of cell types and charging techniques from Lead Acid through NiCd and NiMH to Lithium types.
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Re: I didn't think the usb c power thing was a big deal...

Fri Jul 12, 2019 9:37 pm

davidcoton wrote:
Fri Jul 12, 2019 9:17 pm
BTW, most USB "chargers" are no such thing -- they lack the regulation and protection circuits required to charge a particular battery or cell. The modern charging circuit is usually more associated with the battery or cell than the power supply. Track the development of cell types and charging techniques from Lead Acid through NiCd and NiMH to Lithium types.
In the vast majority of cases the "modern charging circuit" is inside the device containg the cell or battery, eg the phone, tablet, laptop etc. The external "charger" merely supplies raw power to that internal circuitry. For lithium and NiMh cells that internal circuitry monitors cell voltage to determine when to stop the charging current. It may also monitor the charging current and/or cell temperature.

As such the typical "wall-wart charger" is not a charger in the sense that a car battery charger or a AA cell charger is. It is a power supply whose performance is adequate to enable the cell or battery in the companion device to be recharged. Its performance may or may not be adequate for other tasks such as powering a RPi.

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HawaiianPi
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Re: I didn't think the usb c power thing was a big deal...

Fri Jul 12, 2019 9:55 pm

Too much semantics. The subject at hand is a power supply suitable for powering a Raspberry Pi computer, which does need to maintain a reasonably stable 5V output under variable load conditions.

Let's try to stay focused here. This is the Raspberry Pi forums after all. If you really want to be anal about it, anything that supplies power is a power supply, so a pair of wires connected to a mains AC outlet is a power supply.

But I wouldn't connect that directly to my Raspberry Pi. Image
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scorpia
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Re: I didn't think the usb c power thing was a big deal...

Fri Jul 12, 2019 11:34 pm

There are quite a few clickbaity articles on this topic now (and a large amount of other add revenue farming articles as well based on my received word-press pingbacks), I started to see quite a few of them once techrepublic and other tech news sites featured the story (was amusing to see my google suggested news stories be mostly articles I discovered the content for for a few days). In my opinion the major result of the issue was that the pi would not to work with a power supply/cable that works everywhere else in a way that would be hard for a non tech savvy user to work out why (have seen several discussions about this when visiting referral links to my blog post on the issue). Now that the article is so widely spread the solution should be fairly easy to find when googling so provides some level of mitigation, but glad it will be properly resolved somepoint in the future with the next board revision (hopefully the USB-C backpowering issue in gadget mode will be fixed then as well).

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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 9:19 am

HawaiianPi wrote:
Fri Jul 12, 2019 9:55 pm
Too much semantics.
Agreed. Bottom line is that it is the actual electrical characteristic of the thing which determines whether it is suitable to power a Pi or not. That is regardless of what it gets called or sold as, regardless of what any labelling suggests its electrical characteristics are.

The official USB-C power supply works.

Some third party USB-C products work.

Some third party USB-C products which could and should work don't because of the circuitry on the Pi 4 board or the cable being used.

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HawaiianPi
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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 9:52 am

hippy wrote:
Sat Jul 13, 2019 9:19 am
Some third party USB-C products which could and should work don't because of the circuitry on the Pi 4 board or the cable being used.
Yup, USB-C is complicated. The funny thing is, most of the PSU/chargers that don't work probably cost more than the Pi4 itself, and most of the "e-marked" cables cost more than the official power supply. Why would anyone want to use a $60 charger and a $15 cable to power a $35 Pi?

So all this nonsense really is getting blown out of proportion.

Just buy the $8 official PSU. Problem solved.
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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 10:13 am

HawaiianPi wrote:
Sat Jul 13, 2019 9:52 am
The funny thing is, most of the PSU/chargers that don't work probably cost more than the Pi4 itself, and most of the "e-marked" cables cost more than the official power supply.
I think that's why it has become such a public issue. The Pi should work with those eye-wateringly expensive USB-C compliant PSU/chargers and cables yet it doesn't.

I would likely be somewhat peeved if I happened to have one of those and then found I had to buy another supply, cable or adapter to make my Pi work, and that provides the foundation for those who choose to publish articles regarding the issue.

Good and bad news about the Pi attracts clicks so one cannot really blame publications for seizing on whatever the latest Pi news may be. Hyperbolic articles are nothing new and one just has to take the rough with the smooth.

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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 10:45 am

HawaiianPi wrote:
Fri Jul 12, 2019 5:19 pm
If it's designed to charge a battery, it's a charger, and may get away with poor voltage regulation. Doesn't matter if it can also be used to power the device while charging (the battery is what powers the device, and also acts as a rudimentary UPS). Even if the Pi4 was compliant, we'd probably be dealing with the same kind of nonsense we went through with the Pi3 and chargers.
Other SBCs have solved that by requesting 9V from the USB-C charger, and regulate that down to 5V and the other voltages they need themselves.
Something that could also be considered.

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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 11:36 am

Just buy the $8 official PSU. Problem solved.
That's what I have. But the official PSU needs a mains socket all to itself which is a bit of a nuisance. I have a selection of 4 port usb chargers which can power my other pis, breadboard, esps etc and charge my phone all at the same time.
No doubt some of these could also power the pi 4, if I had any usb c cables.

It is a bit confusing that the advice for a pi 3 cable is "buy an expensive one" and for a pi 4 "buy a cheap one".

Has anyone tried running the pi 4 with one of the power packs that work for the pi 3?

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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 12:01 pm

jbudd wrote:
Sat Jul 13, 2019 11:36 am
...t the advice for a pi 3 cable is "buy an expensive one" and for a pi 4 "buy a cheap one".
No it is not. The advice for both has been to buy the official one and both are reasonably priced.
jbudd wrote:
Sat Jul 13, 2019 11:36 am
Has anyone tried running the pi 4 with one of the power packs that work for the pi 3?
Yes, have you not seen the several reports on these forums from posters who have successfully done that? There is even an official adaptor to enable that. https://www.raspberrypi.org/products/us ... c-adapter/

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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 12:13 pm

No I hadn't. Thanks for that.

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rin67630
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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 3:16 pm

Anyhow, I use to not power the Pi directly but add a 2$ stepdown bucket converter and use a regular power jack feeding something between 7V and 20 DC. Everybody has such power supplies left over. It is MUCH safer for the Pi and you newer get a low-voltage indicator again.

Fraoch
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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 4:21 pm

hippy wrote:
Sat Jul 13, 2019 10:13 am
Good and bad news about the Pi attracts clicks so one cannot really blame publications for seizing on whatever the latest Pi news may be. Hyperbolic articles are nothing new and one just has to take the rough with the smooth.
Yeah it's too bad this actually minor issue is detracting from the rather amazing performance of the Pi4 - THAT's what the news should be about. Been updating all my Pis to the new Buster lately and the performance of the Pi4 is way ahead of even the rather fast Pi3B+.
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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 4:45 pm

As regard the thread title... I still don't think the USB-C power thing is a big deal. It's more like a tempest in a teapot.

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hardwaremack-orginal
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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 5:45 pm

This thing powers my PI4B great.
1 x 18650
https://www.ebay.com/itm/3V-5V-Wemos-ES ... SwsYpaDb58
3569e0b59f1abede.jpg
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hardwaremack-orginal
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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 5:58 pm

windows and mac GUI have it down.

Linux GUI's over all is kind of not fantastic, --- GUI offered is fantastic considering its free.
What needs to happen is GUI needs to be 100% rendered using the 3D hardware, as soon as that happens
i think we will be golden on the Linux side.

my PI4B is running 4k@30hz the mouse pointer is laggy as heck.
my DELL screen apparently will only do 4k@30hz through the HDMI cable i have to use the DP or mDP
for 4k@60hz so i bought an HDMI to DP adapter... maybe that will work?
The Pi4B over all GUI is sluggish and just not that enjoyable to use, though it does work.

I have a $500.00 dell latitude 11" SSD touchscreen etc I deleted W10, and have been experimenting wtih MINT.Peppermint,Ubuntu, and Ubuntu MATE. So far 64 bit MINT seems to function the best for this laptop. BUT even the gui on this is not that fantastic as i think the GRAPHICS hardware is capable of.

Cant they Make a GUI that is 100% rendered in openGL?

trejan
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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 7:05 pm

10+ USB-C cables tested with a RPI 4. Most are fine. Avoid Apple Macbook cables and cables that say they're capable of 10Gbps+ operation.
Last edited by trejan on Sat Jul 13, 2019 7:09 pm, edited 2 times in total.

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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 7:06 pm

hardwaremack-orginal wrote:
Sat Jul 13, 2019 5:58 pm
windows and mac GUI have it down.
Yeah...well both those GUI are "built in" to the OS. IMHO, a rather bad mistake. Not surprising with Windows, but Apple should have known better, considering what the underlying kernel started out as.
Linux GUI's over all is kind of not fantastic, --- GUI offered is fantastic considering its free.
At least one can *choose* what sort of GUI one wants, or even write a new one, if you are so inclined.
What needs to happen is GUI needs to be 100% rendered using the 3D hardware, as soon as that happens
i think we will be golden on the Linux side.
I beleive the trend is in that direction on the Pi4B.
Cant they Make a GUI that is 100% rendered in openGL?
How is your C?

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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 7:06 pm

trejan wrote:
Sat Jul 13, 2019 7:05 pm
10+ USB-C cables tested with a RPI 4. Most are fine. Avoid Apple Macbook cables and cables that say they're capable of 10Gbps+ operation.
Hmmm.. So avoid USB-C 3.1 cables.

trejan
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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 7:09 pm

W. H. Heydt wrote:
Sat Jul 13, 2019 7:06 pm
Hmmm.. So avoid USB-C 3.1 cables.
Yeah. They're far more expensive anyway.

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Re: I didn't think the usb c power thing was a big deal...

Sat Jul 13, 2019 11:38 pm

bensimmo wrote:
Fri Jul 12, 2019 6:01 pm

I know people who call laptop power supplies chargers, even though they can run the computer off it without the battery it.
Laptop power supplies ARE chargers (or at least only designed to provide power to a charging circuit)- you can run the computer from one but as I discovered, when my MacBook battery died, only at reduced speed, because the power supply/charger could not supply sufficient current and relied on the battery to supply peak current.

Modern laptops using USB-C (and some using µUSB) DO NOT run/charge from 5V, they negotiate a higher voltage.
Indeed it is physically impossible to fit sufficiently large cables to supply 3A at acceptable voltage drop (<0.2V) into one of these tiny connectors.

Regardless of which connector is used, the Pi - which requires 5V±0.25V is always going to be limited by cable resistance. Simple calculations of wire resistance for reasonable cable length produce surprising results.

Of course, it would be relatively simple to build a charger with feedback from the connector to compensate for voltage drop in the cable, although a 5V regulator on the Pi would be a better option (but unlikely).

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