19 ms·

Raspberry Pi 4 not working with some chargers

401 points by styx31 7y ago

ilikepi 7y ago
So the take-away for consumers is...what exactly? Don't use certain types of cables to power a RaspberryPi 4? And how does one identify a cable that could cause problems?
- HappyRobot 7y ago
  I don't think there is any take away for consumers. This seems to be an explanation for why certain cables do not work and how to avoid this issue when designing electronics that accept USB-C power input.
- qmarchi 7y ago
  Although the blog post is directed towards the Raspberry Pi Foundation, consumers essentially only have one option, use a "dumb" cable.
- kenny_r 7y ago
  My personal take-away is "hold off on buying a Pi4 until this issue has been addressed in a future revision".
  - tryptophan 7y ago
    My takeaway is "use the official $8 charger they sell".
    - baq 7y ago
      i bought the rpi4 and the official charger and the combo works FWIW. it's good to know that it just might not work with some cables though. probably saved a few hours of head scratching in the future for a few folks.
    - walshemj 7y ago
      But if you want to power a cluster from a single beefier usbc power pack
    - TeMPOraL 7y ago
      I'd agree (and that's what I did) except here I'd suggest "maybe wait until they solve the core overheating issue". Mine is idling at 64°C now that I took off the official cover; with the cover on, it was idling just below the CPU throttling point of 80°C, which meant that almost any computation caused it to start intermittently locking up.
      - zamadatix 7y ago
        Odd, mine is idling at 49 C in a 21 C room. This is the 4G version running fully updated Raspbian without the desktop (one of the updates fixed the USB controller using a lot of power at idle).
        TeMPOraL 7y ago
        Mine is 4G too; I installed heatsinks on it couple hours ago and it now sits at 61°C idle, with an external HDD attached (but not under I/O load) to USB 3 port. Slightly better, though arguably still ridiculously high.
      - snovv_crash 7y ago
        Apparently this will be fixed with a PCIe firmware update, they're just figuring out the best way to roll this out.
        gadgetoid 7y ago
        It looks like it'll be mitigated (https://www.tomshardware.co.uk/raspberry-pi-4-firmware-update-tested,news-61071.html https://www.tomshardware.co.uk/raspberry-pi-4-firmware-updat...), but not necessarily fixed- making a difference of a few degrees. Active cooling makes a huge difference, which is why it baffles me that the official case has no ventilation.
      - ehonda 7y ago
        I did not buy the official cover, but a cheap top/bottom (but not side) acrylic case that included a fan, and also applied 3 heat sinks which came in the basic kit that came with the pi from canakit. It idles at 47°C and can browse "new reddit" at 59°C. A samba share its hosting causes it to run at 59°C during file transfers to an external SATA drive connected to the USB 3 port. I'm pretty happy with it considering all the complaints about heat issues. Only issue I've had so far is that you cannot reliably power more than one external hard drive with this. A second one will need its own power adapter. There was a firmware update, so make sure you applied that. Might help bring the temps down a bit.
  - ohazi 7y ago
    You'll be waiting for a Pi4+ or a Pi5, then. They've had similar "minor" bugs with trivially easy hardware fixes on older boards, but punted on fixing them until the next major version. I could be wrong, but AFAICT, they've never done a minor board revision for an already released Raspberry Pi.
- tracker1 7y ago
  I had so many issues with 3B+, that I won't even use a power adapter/cable that wasn't sold as working with the Pi in the first place.
Roritharr 7y ago
Wow, this is really bad. I have enough USB-C incompatibility in my life to make this the issue that makes me not order the Raspberry 4 until this issue is sorted out.
- toomuchequate 7y ago
  Can you list examples where it hasnt worked? I support a USB system and I this was my worry since day 1. Curious, and it would be helpful
  - Roritharr 7y ago
    The usual fare of Dongle Incompatibility, we have a Dell USB-C Dongle that won't provide display outputs to anything that's not a specific Latitude Model, we have quite a few HP Notebooks that won't properly charge with standard USB-C Chargers (even Apple ones), then there's the USB-C Audio Adaptor issue where some phones output analog audio via USB-C and others need an active adaptor with a DAC, which look physically identical... The Standard, if you fully embrace it, is a mess.
- makomk 7y ago
  They've improved a bit over the years. The power screwup on the original Pi meant that some boards wouldn't work reliably at all with any power supply. (They mistook the 1.8v output from the USB+ethernet chip's internal regulator for an input and connected it to the 1.8v rail that powered everything else on the board, meaning that for some unlucky folks it ended up supplying 1.8v power to the entire board, overheating spectacularly, and falling over. It took an outside engineer to find that one after the folks who designed it blew off all the complaints about overheating Ethernet chips, USB falling over, etc as user error. In fact, they were so confident all the problems were user error that they banned the person who spotted their mistake from their forums for pointing it out.)
- imtringued 7y ago
  Just get the official power supply then.
pavlov 7y ago
Before we had separate ports and cables for power, USB and Thunderbolt. There was no way to plug the wrong cable in the wrong port. With USB-C, we still have separate cables for these three types, but they all look confusingly the same. Not convinced this is an improvement.
- timw4mail 7y ago
  A fully-featured USB-C cable can be used for all of those functionalities, but the fact that there are lesser-featured cables is confusing, yes.
  - deleted 7y ago
    [deleted]
  - VBprogrammer 7y ago
    To be fair, I've cut open pound store USB-B cables before only to discover that they contained literally 2 strands of copper (Or at least I hope it was copper). The idea that people are trying to sink 2 amps down that type of cable is a bit frightening. I guess the point I'm trying to make is, specs are great, but the reality is that there are infinitely many types of cable and the only thing which definitively defines the capabilities is physics.
    - KirinDave 7y ago
      Even bad USB cables are gonna have total resistances below 150mΩ, and that's including contact resistance on both ends. Unless you're shorting the cable inside the contacts (you do short pins to make USB deliver power, but upstream ports gotta spec for shorts anyways), even bad cables are unlikely to be a severe risk. The nice part of DC is you get to use the entire cross section of the wire. So 2A at 5V isn't gonna start too many fires even on thin wire. Now hopefully we don't see too many folks start using USB-PD 3 with crappy but compliant cables, as my comfort with DC drops as we go up into 20V 5A territory.
      - 7y ago
MobileVet 7y ago
Curious what led to this decision. Reference schematics exist for a reason... It seems odd to not use them.
- nerdponx 7y ago
  That's what I was thinking. I've recently gotten into hardware design myself as part of a hobby, and this is something I learned early on. I'm sure they had good reasons to deviate from the reference (I assume they are experienced hardware designers over there), but I'd be very curious as to what those reasons were.
  - MobileVet 7y ago
    Considering the heavy emphasis on budget, it could very well have been on reduced cost. Is a single resistor expensive? No but each decision adds up and it may just be ingrained in the team's ethos. Many times if we push something too hard, we apply the rule without questioning whether it truly makes sense in a particular situation.
    - voidwtf 7y ago
      In this case they directly shorted two pins together though. That would give me pause to ask why the two pins existed in the first place. Something that should have led to the conclusion the author reached about the configuration.
      - MobileVet 7y ago
        I personally agree and would have been curious myself. That said, someone with less experience might have just said ‘oh cool, I can be clever and reduce our BOM’ and not given much thought to it.
      - michaelt 7y ago
        That would give me pause to ask why the two pins existed in the first place. Bear in mind, the USB-C connector is designed to be rotationally symmetric - so you'll start your layout by paralleling up the four ground pins, and the four bus power pins, and the two pins for USB 2.0 negative and the two for USB 2.0 positive. I can understand why it might get overlooked, when someone has paralleled up 12 pins in the last 5 minutes...
timw4mail 7y ago
The Raspberry Pi foundation has their own "official" USB-C power adapter as well (At least, they have it for pre-order). So I doubt it's the highest priority. I can still see this getting fixed in a future revision, but I think it will be a while. It is an issue, but it doesn't make the pi 4 useless.
- jws 7y ago
  When I saw the official adapter was 5.1 volts I just mentally relabeled that port as “proprietary power port” and got their adapter. They fudged their power supply voltages up on previous models to handle drop in the regulators. I presume that will be an issue on these as well.
- agumonkey 7y ago
  I see it as an 'exercise left for the reader'
- Traster 7y ago
  This is going to be a really sticky issue for a consumer. Randomly not working with some subset of USB-C cables is the sort of thing you expect the engineering team to consider - and they missed it. How do you think the average enthusiast is going to figure out that their Pi4 no longer works because of the USB-C cable they're using? At best they'll decide the cable is faulty, use a different cable and probably bin the old one, at worst they'll just come to the conclusion the Pi is bricked and bin it.
  - morsch 7y ago
    How do you think the average enthusiast is going to figure out that their Pi4 no longer works because of the USB-C cable they're using? Presumably they're going to search for pi 4 does not power on and get their answer as the first search result[1]. You know, the same way the average enthusiast figures out the other twenty seven roadblocks they stumble on during their RPi project. Not to minimize that it'll be an issue for those people who don't happen to have a compatible charger laying around. [1] For me, at the time of posting: https://hackaday.com/2019/06/28/power-to-the-pi-4-some-chargers-may-not-make-the-grade/ https://hackaday.com/2019/06/28/power-to-the-pi-4-some-charg...
consp 7y ago
I would not be surprised if this is the default in the bcm2711 documentation and they simply took that as guidance.
amelius 7y ago
> The short summary is that bad things (no charging) happens if the CC1 and CC2 pins are shorted together anywhere in a USB-C system that is not an audio accessory. Why should it matter what kind of accessory it is used in? > Each CC gets its own distinct Rd (5.1 kΩ), and it is important that they are distinct. Why? I think this article was not written by an electrical engineer. The reason why this design is inadequate still eludes me. But, RPi should have probably used the reference design, that's clear.
- InitialLastName 7y ago
  > Why should it matter what kind of accessory it is used in? I suspect you're misunderstanding what they mean by "audio accessory". They don't mean "a standard digital USB device that happens to do audio-related things". USB-C has a special-case allowance to drive analog audio signals through the port (to allow all-analog headphones and such) that has its own CC configuration. >> Each CC gets its own distinct Rd (5.1 kΩ), and it is important that they are distinct. > Why? Because of the above; if the CCs use the same Rd, they're shorted together by definition, which isn't allowed to happen. Especially since the USB-C format uses the CC's to determine plug orientation.
  - dTal 7y ago
    >USB-C has a special-case allowance to drive analog audio signals through the port Wat. Just when I think I've heard it all...
    - floatboth 7y ago
      You've seen the Type C - 3.5mm headphone dongles right? They're so tiny and cheap.. did you think they could be active? :)
      - deleted 7y ago
        [deleted]
    - cesarb 7y ago
seaborn63 7y ago
I read it but I have no idea what it meant. I am very interested in getting a Pi4, so can some of you more knowledgeable folks help me understand what this means?
- wereHamster 7y ago
  The Pi4 does not work with all USB-C chargers. You may be lucky and it will work, or you may be unlucky and it will not work and you will have to buy another USB-C charger (which again may not work). The reason is that the developers of the Pi4 made a mistake while designing the electronic circuit. They tried to design it themselves instead of copying it from the specification.
  - JshWright 7y ago
    The other reason for is that the developers of the USB-C specifications left us with a terrible confusing mess where visually identical cables have different capabilities and behaviors.
    - derefr 7y ago
      If it’s confusing, just don’t use it. They could have stuck with a micro-B charger, or a custom charger, and no one would have questioned it. Instead, they decided they were confident enough in their understanding of USB-C to implement it on their device. And they were wrong.
      - JshWright 7y ago
        I said the "other" reason. I am not absolving the RPi team here... The fact that they shipped this reveals significant gaps in their engineering and QA processes. That doesn't change the fact that USB-C is a mess, and that mess contributed to this failure.
      - TremendousJudge 7y ago
        >They could have stuck with a micro-B charger Somebody here said they were running into the maximum rated current for the port >or a custom charger Literally everyone would have complained
crshults 7y ago
Had to fire up Eagle quick and take a look at my latest design (first time using USB-C). Looks like I got lucky this time.
- deleted 7y ago
  [deleted]
michaelt 7y ago
The fact that no QA team inside of Raspberry Pi’s organization caught this bug indicates they only tested with one kind (the simplest) of USB-C cable. Raspberry Pi, you can do better. I'd say at least 20% of the blame lies with whatever genius decided to have multiple types of USB-C cable I mean, cables already suffer from having A, Type A SuperSpeed, B, B SuperSpeed, Mini-B, Micro-B, Micro-B SuperSpeed, C, and lengths from 10cm to 5m. Who'd expect adding a complete extra dimension of difference to be trouble-free?
- ProblemFactory 7y ago
  I believe the original plan was the opposite - one port and one cable type that can do everything - 100W of power, 5K video, USB devices, analog audio, Ethernet and more. But it was naive to think that manufacturers will ship a $30 cable for a phone charger when a cheaper hack will do. At least there should have been mandatory color coding of the "full" and "limited" ports and cables, just as USB 3 ports were blue to distinguish them from older versions.
  - y4mi 7y ago
    Until cheap knockoffs heard they could charge 4x their normal price by changing the coloring. ... You can't trust the coloring either if you're buying off of Amazon, eBay or any Chinese site like Alibaba
    - Wowfunhappy 7y ago
      Coloring appears to have worked for distinguishing between USB 2 and USB 3, at least in my experience.
      - katbyte 7y ago
        With USB 3 isn’t the other end of the cable usually different as well?
        deleted 7y ago
_wmd 7y ago
Pretty unfortunate design flaw, and hopefully it can be corrected, but this post is horribly finger-pointy and the tone generally stinks. Would hate to make a mistake while working around this guy Can the link be changed to the apparent source article? It's not as bad. https://www.scorpia.co.uk/2019/06/28/pi4-not-working-with-some-chargers-or-why-you-need-two-cc-resistors/ https://www.scorpia.co.uk/2019/06/28/pi4-not-working-with-so...
- MobileVet 7y ago
  Seriously. Considering what a cluster the spec is and the budgetary goals for a project like the Pi, this feels really harsh. The focus is on the mistake and how trivial it was without any thought of why or how. Pointing out mistakes can be done without being such a jerk about it.
  - joelhaasnoot 7y ago
    They spend months if not years on the design and crank out millions. Getting USB-C right seems like a no-brainer!
    - MobileVet 7y ago
      I highly doubt they spent years on the design... But regardless we all make mistakes. What is a no brainer to you may not be to everyone. Besides, you are fundamentally assuming this was a mistake and not a deliberate design decision. Maybe they prioritized X over following the spec 100%. I may not make that decision, but that doesn’t mean they didn’t.
  - arghwhat 7y ago
    This is exactly why the presence of this mistake appears very careless. When you are met with a complicated spec with known issues, do you test more or less? I know which I'd pick, and if they had tested common cables like those from Google or Apple (I'm sure someone has a macbook), they'd see it not work.
  - pas 7y ago
zimbatm 7y ago
TIL; there are different types of USB-C cables with functional differences. How do you know what type the cable is? Is is possible to detect it visually?
- pixl97 7y ago
  You can detect it visually by the sparks and smoke coming out of your device.
  - ineedasername 7y ago
    Sure, but what color sparks? In my experience, standard orange sparks mean you just killed a component. Blue sparks mean you just did something very interesting, but not too healthy. Green sparks mean you're scraping thin the boundaries of reality, and Eldritch horrors are looking at you in hunger.
- XaspR8d 7y ago
  Also curious about differentiation strategies, if anyone has tips. I'm guessing the marketing materials for the cables isn't even sufficient to tell them apart in many cases. It's tempting to build some sort of test rig for this (though I hardly have the background for it)...
  - cesarb 7y ago
    I don't have a USB-C device right now to check, but according to https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-class-typec https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-c... there might be some information at /sys/class/typec/<port>-cable
  - pault 7y ago
    There are lots of testers on the market, but it's hard to differentiate them and I'm sure many of them are garbage. I need one myself, but I haven't had the time to do the research yet.
- ProblemFactory 7y ago
baybal2 7y ago
Usb PD + type C is hard. You have to read specs for days just to get a basic idea of the logic governing the negotiation protocol. I'm waiting for a single chip solution that will take upon the pain of dealing with Type-C for me. Besides the complexity of the spec itself, another "landmine" in dealing with Type C + PD is the divergence of different PD implementations, proprietary extensions from big brands, and... DRMed power supplies along with devices with DRMed PD devices... Yes, the electricity is now copyrighted too.
- brandmeyer 7y ago
  Common misconception: USB Power Delivery is not what the RPi4 is doing. The base Type-C spec provides the schematic for analog signaling of either a 5V/1.5A or 5V/3A state. USB-PD uses a much more complex digital signaling method across the CC lines, and is its own separate spec.
  - baybal2 7y ago
    Yes, it is not a PD. I am talking specifically about the case of doing USB fast charging aka USB PD, which is much, much more complex
    - brandmeyer 7y ago
      The entire USB power situation is complex. Lets see, there's pre-enumeration classic 5V/100mA, post-enumeration 5V/500mA, a host of proprietary signaling methods for additional power, the more or less de-facto BC 1.2 method for extra power, Type-C analog signaling for 5V/1.5A or 5V/3A power, and USB-PD digital signaling. Oh, and there's also Type-C VCONN power in addition to VBUS power. The irony in all this is that Type-C analog signaling was meant to greatly simplify the market situation and UX well above and beyond what happened in the micro-B charger world. And it is simpler. RPi4 just goofed in their implementation.
moonbug 7y ago
Says more about the quality of no-name usb wotsits
gadgetoid 7y ago
Ever since the very first model, sub-par, underrated power supplies have been responsible for a good slice of tech support issues with the Pi. It wouldn't be a real Pi launch without power issues. IIRC the Pi 3B+ was butting up against (if not exceeding) the maximum rated current for the microUSB port, so I believe the switch to USB Type-C is more about picking a port that can handle a 3A@5V supply than a conscious effort to support the dozens and dozens of terrible and near arbitrary USB Type-C supplies on the market (some output 12V with zero negotiation. You know- for giggles). I'd be surprised if they tested with more than a couple of staff phone chargers and their own-brand chargers. I can't imagine the idea of anyone using an expensive power-delivery enabled dock with a thick, 40cm Thunderbolt 3 cable really entered their minds. My advice to anyone buying a Pi 4 would be "Just buy a Pi-branded power-supply. They're inexpensive and guaranteed to work." Granted you might want to save a few bucks and use your phone charger... but then what are you going to use to charge your phone?
- DangerousPie 7y ago
  > Ever since the very first model, sub-par, underrated power supplies have been responsible for a good slice of tech support issues with the Pi. It wouldn't be a real Pi launch without power issues. Except this time the issue is not with the power supplies by the Pi itself.
  - gadgetoid 7y ago
    I think the problem is that people see a USB Type-C port and expect everything with a USB Type-C connector to work in it, which has and never will be the case with USB Type-C connectors. If you think this is bad, go ask PlanetCom what the heck "Pump Express" is and why USB Type-C PD power supplies wont charge their phone ;)
    - jrockway 7y ago
      Nintendo also interpreted the USB Type-C standard interestingly.
fortran77 7y ago
Everything works for me except my Apple charger. I blame Apple.
- LIV2 7y ago
  The linked article shows how it's due to a design flaw and explains why shitty cheap chargers/cables work but ok
- Tepix 7y ago
  Wrongly.
- jesseb 7y ago
  Apple followed the specification, the Pi 4 does not. How is this Apple's fault?
an_d_rew 7y ago
There have been a lot of comments here but I want to leave one specifically to the person or team who designed the Pi’s circuitry: Thank you for working on such an important project and thank you for all the things that you got right. I’m sure that somewhere, someone is feeling a little bit embarrassed and possibly somewhat sheepish over this and… Please don’t let one incident overshadow all the great things that have come from the existence of the Raspberry Pi!
- jaclaz 7y ago
  I would add - for what it may count - that IMHO there is an issue with the actual USB-C "standard" (not unlike many other standards that have been made by this or that "technical committee" into a large mass of mostly unreadable stuff). The document (that you can find here [0]) is a 27 Mb .zip [0] https://www.usb.org/document-library/usb-type-ctm-cable-and-connector-specification-revision-14-march-29-2019 https://www.usb.org/document-library/usb-type-ctm-cable-and-... inside there are various .pdf files, the most interesting is the one named "USB Type-C Specification Release 1.4 - Redline from 1.3.pdf" , besides highlighting the changes, some minor like changing "existing" to "legacy USB", it makes clear that the matter is complex. The specification, remember only for USB-C connector and cable, is 338 pages, I wouldn't be so hard with someone that missed something in them.
  - LaughingMan11 7y ago
    It's one thing if an enthusiast made a mistake putting together a one-off breadboard for a board they're hacking on. But it's entirely a different problem if a professional engineering organization, with a hardware release process, a factory build process, and a QA process didn't read the spec properly and didn't catch this bug. If it's someone's profession to do engineering, don't give them a pass for not being able to follow an industry specification. Engineering is all about following arcane rules in various specs. If it's not USB, then it's Wifi or Bluetooth, or whathaveyou specs, which are all similarly complicated. For what it's worth, the USB spec is complicated, but in this case, there's actually a picture in the USB Type-C Spec you linked to which tells hardware designers exactly how to put together this circuit. They should have just copied it directly instead of going off-script. I wrote about it here, and included the figure from the spec: https://medium.com/@leung.benson/how-to-design-a-proper-usb-c-power-sink-hint-not-the-way-raspberry-pi-4-did-it-f470d7a5910 https://medium.com/@leung.benson/how-to-design-a-proper-usb-...
cesarb 7y ago
There might be yet another issue. As commented by the author of this blog post in the RPi forums (https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=243875#p1492674 https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=2438...): "Also the 5v on the connector is connected directly to the 5v rails. If the pi is powered over the GPIO then the USB-C connector is vbus hot which means it could backfeed devices when using the type C port on the pi as a USB client." That is, when powering the RPi4 through PoE, its USB-C connector is in an invalid configuration: it's powering VBUS when it shouldn't (that is, unlike USB-A where VBUS is always on, IIRC with USB-C it should only be turned on when the CC pins detect that the other side is either a power sink or an adapter which should source power).
- londons_explore 7y ago
  Backfeeding power is one of those things that is 'technically' a bad idea, but practically damages pretty much nothing.
  - TylerWard 7y ago
    Another potential issue here is that if using the Pi as a client with a C-C cable this could confuse the device at the other end meaning it wont connect as it thinks it is being charged (will be seeing if I can get this to occur over the weekend).
    - TylerWard 7y ago
      Have just run this test and it does appear to confuse some USB-C ports (my phone and 3.0 usb-C port on my laptop detect the pi gadget however the 3.1 usb-C port doesn't detect the gadget if the pi is powered by gpio).
chx 7y ago
How does the HN system work when I submitted the exact same URL https://news.ycombinator.com/item?id=20317687 https://news.ycombinator.com/item?id=20317687 five days ago??? We have stickied this on the usbchardware subreddit as well at the time, it's still on the top: https://www.reddit.com/r/UsbCHardware/ https://www.reddit.com/r/UsbCHardware/ We have a nice wiki and if you are still confused about USB C, ask away, we try to help (chances are, I will answer :) ). You will also find a wonderful cornucopia of interesting USB C devices -- not just the usual chargers, power banks and docks but also a toothbrush, a razor, headphones, speakers, video lights, a soldering iron... we like USB C :)
- tracker1 7y ago
  Just guessing the person that submitted later has significantly more karma or popularity. It seems to happen quite a bit. There's also time of day to consider, it's possible this made it in when more people are browsing by newest and upvoted pretty early.
  - glenneroo 7y ago
    chx has 8000+ karma whereas OP has ~600, so scratch that as a possible explanation. I would also guess it mainly depends on the time of day.
  - chx 7y ago
    The question rather is, why would the system allow the same URL to be submitted twice. In the past when I tried to submit something already in, I was redirected to the existing post and my submissions was converted into an upvote.
    - hombre_fatal 7y ago
      A five-day-old HN submission is effectively dead. Would make sense if the behavior you describe only happens to dupe urls within 24hr of each other if the first one hit a certain threshold of traction. Else makes more sense to allow the dupe submission to give it another shot.
    - 7y ago
w0mbat 7y ago
There's a project management lesson here. Raspberry Pi 4 was planned for 2020, but the Broadcom SOC went final much sooner than expected, so they shipped the Pi 4 this year. This sounds like a great thing, but the earlier release meant that the board as a whole spent less time being used internally before release, and they didn't have the time to shake out bugs like this. The lesson: when you move to a faster release cadence, you need to be more rigorous about QA because you have less time to find problems before release.
geekamongus 7y ago
I just wish I could find a 4GB Pi 4 in stock/for sale so that I could even have this problem.
- sbisson 7y ago
  I ordered one yesterday from the Pi Hut here in the UK. It shipped today...
Scuds 7y ago
Odroid, Latte Panda, Pine, and others went with dedicated tried and true barrel jacks. I appreciate re-using the same microusb cables and chargers for my iPhone and headset charger for my Pi3, and not having to handle Yet Another Wall Wart, but barrel jacks would have sidestepped this whole issue. Were they hoping to have users use a single cable deliver power and data over a single cable usb just like a pi zero w? https://desertbot.io/blog/ssh-into-pi-zero-over-usb https://desertbot.io/blog/ssh-into-pi-zero-over-usb God DAMN I hope this doesn't turn into a recall.
- Narishma 7y ago
  Why would this turn into a recall? AFAIU, this is just an inconvenience, not a show-stopper since it only affects high-end cables.
mrlambchop 7y ago
The Pi people are good folk - all that is needed is to run the USB 3 conformance tests and report back the results (both as USB PD sink and source). Better to know the knowns than have a enthusiastic fan base find them and we get into discussions like this! I'd also recommend they put up a compatibility table of power supplies on their website in time - probably cables as well! Its a good opportunity to collaborate with the Google engineer who has been spending his non-core hours on the USB-C madness.

401 points by styx31 7y ago

So the take-away for consumers is...what exactly? Don't use certain types of cables to power a RaspberryPi 4? And how does one identify a cable that could cause problems?

HappyRobot 7y ago
I don't think there is any take away for consumers. This seems to be an explanation for why certain cables do not work and how to avoid this issue when designing electronics that accept USB-C power input.
qmarchi 7y ago
Although the blog post is directed towards the Raspberry Pi Foundation, consumers essentially only have one option, use a "dumb" cable.
kenny_r 7y ago
My personal take-away is "hold off on buying a Pi4 until this issue has been addressed in a future revision".
- tryptophan 7y ago
  My takeaway is "use the official $8 charger they sell".
  - baq 7y ago
    i bought the rpi4 and the official charger and the combo works FWIW. it's good to know that it just might not work with some cables though. probably saved a few hours of head scratching in the future for a few folks.
  - walshemj 7y ago
    But if you want to power a cluster from a single beefier usbc power pack
  - TeMPOraL 7y ago
    I'd agree (and that's what I did) except here I'd suggest "maybe wait until they solve the core overheating issue". Mine is idling at 64°C now that I took off the official cover; with the cover on, it was idling just below the CPU throttling point of 80°C, which meant that almost any computation caused it to start intermittently locking up.
    - zamadatix 7y ago
      Odd, mine is idling at 49 C in a 21 C room. This is the 4G version running fully updated Raspbian without the desktop (one of the updates fixed the USB controller using a lot of power at idle).
      - TeMPOraL 7y ago
        Mine is 4G too; I installed heatsinks on it couple hours ago and it now sits at 61°C idle, with an external HDD attached (but not under I/O load) to USB 3 port. Slightly better, though arguably still ridiculously high.
    - snovv_crash 7y ago
      Apparently this will be fixed with a PCIe firmware update, they're just figuring out the best way to roll this out.
      - gadgetoid 7y ago
        It looks like it'll be mitigated (https://www.tomshardware.co.uk/raspberry-pi-4-firmware-update-tested,news-61071.html https://www.tomshardware.co.uk/raspberry-pi-4-firmware-updat...), but not necessarily fixed- making a difference of a few degrees. Active cooling makes a huge difference, which is why it baffles me that the official case has no ventilation.
    - ehonda 7y ago
      I did not buy the official cover, but a cheap top/bottom (but not side) acrylic case that included a fan, and also applied 3 heat sinks which came in the basic kit that came with the pi from canakit. It idles at 47°C and can browse "new reddit" at 59°C. A samba share its hosting causes it to run at 59°C during file transfers to an external SATA drive connected to the USB 3 port. I'm pretty happy with it considering all the complaints about heat issues. Only issue I've had so far is that you cannot reliably power more than one external hard drive with this. A second one will need its own power adapter. There was a firmware update, so make sure you applied that. Might help bring the temps down a bit.
- ohazi 7y ago
  You'll be waiting for a Pi4+ or a Pi5, then. They've had similar "minor" bugs with trivially easy hardware fixes on older boards, but punted on fixing them until the next major version. I could be wrong, but AFAICT, they've never done a minor board revision for an already released Raspberry Pi.
tracker1 7y ago
I had so many issues with 3B+, that I won't even use a power adapter/cable that wasn't sold as working with the Pi in the first place.

Roritharr 7y ago

Wow, this is really bad. I have enough USB-C incompatibility in my life to make this the issue that makes me not order the Raspberry 4 until this issue is sorted out.

toomuchequate 7y ago
Can you list examples where it hasnt worked? I support a USB system and I this was my worry since day 1. Curious, and it would be helpful
- Roritharr 7y ago
  The usual fare of Dongle Incompatibility, we have a Dell USB-C Dongle that won't provide display outputs to anything that's not a specific Latitude Model, we have quite a few HP Notebooks that won't properly charge with standard USB-C Chargers (even Apple ones), then there's the USB-C Audio Adaptor issue where some phones output analog audio via USB-C and others need an active adaptor with a DAC, which look physically identical... The Standard, if you fully embrace it, is a mess.
makomk 7y ago
They've improved a bit over the years. The power screwup on the original Pi meant that some boards wouldn't work reliably at all with any power supply. (They mistook the 1.8v output from the USB+ethernet chip's internal regulator for an input and connected it to the 1.8v rail that powered everything else on the board, meaning that for some unlucky folks it ended up supplying 1.8v power to the entire board, overheating spectacularly, and falling over. It took an outside engineer to find that one after the folks who designed it blew off all the complaints about overheating Ethernet chips, USB falling over, etc as user error. In fact, they were so confident all the problems were user error that they banned the person who spotted their mistake from their forums for pointing it out.)
imtringued 7y ago
Just get the official power supply then.

pavlov 7y ago

Before we had separate ports and cables for power, USB and Thunderbolt. There was no way to plug the wrong cable in the wrong port. With USB-C, we still have separate cables for these three types, but they all look confusingly the same. Not convinced this is an improvement.

timw4mail 7y ago
A fully-featured USB-C cable can be used for all of those functionalities, but the fact that there are lesser-featured cables is confusing, yes.
- deleted 7y ago
  [deleted]
- VBprogrammer 7y ago
  To be fair, I've cut open pound store USB-B cables before only to discover that they contained literally 2 strands of copper (Or at least I hope it was copper). The idea that people are trying to sink 2 amps down that type of cable is a bit frightening. I guess the point I'm trying to make is, specs are great, but the reality is that there are infinitely many types of cable and the only thing which definitively defines the capabilities is physics.
  - KirinDave 7y ago
    Even bad USB cables are gonna have total resistances below 150mΩ, and that's including contact resistance on both ends. Unless you're shorting the cable inside the contacts (you do short pins to make USB deliver power, but upstream ports gotta spec for shorts anyways), even bad cables are unlikely to be a severe risk. The nice part of DC is you get to use the entire cross section of the wire. So 2A at 5V isn't gonna start too many fires even on thin wire. Now hopefully we don't see too many folks start using USB-PD 3 with crappy but compliant cables, as my comfort with DC drops as we go up into 20V 5A territory.
    - 7y ago

MobileVet 7y ago

Curious what led to this decision. Reference schematics exist for a reason... It seems odd to not use them.

nerdponx 7y ago
That's what I was thinking. I've recently gotten into hardware design myself as part of a hobby, and this is something I learned early on. I'm sure they had good reasons to deviate from the reference (I assume they are experienced hardware designers over there), but I'd be very curious as to what those reasons were.
- MobileVet 7y ago
  Considering the heavy emphasis on budget, it could very well have been on reduced cost. Is a single resistor expensive? No but each decision adds up and it may just be ingrained in the team's ethos. Many times if we push something too hard, we apply the rule without questioning whether it truly makes sense in a particular situation.
  - voidwtf 7y ago
    In this case they directly shorted two pins together though. That would give me pause to ask why the two pins existed in the first place. Something that should have led to the conclusion the author reached about the configuration.
    - MobileVet 7y ago
      I personally agree and would have been curious myself. That said, someone with less experience might have just said ‘oh cool, I can be clever and reduce our BOM’ and not given much thought to it.
    - michaelt 7y ago
      That would give me pause to ask why the two pins existed in the first place. Bear in mind, the USB-C connector is designed to be rotationally symmetric - so you'll start your layout by paralleling up the four ground pins, and the four bus power pins, and the two pins for USB 2.0 negative and the two for USB 2.0 positive. I can understand why it might get overlooked, when someone has paralleled up 12 pins in the last 5 minutes...

timw4mail 7y ago

The Raspberry Pi foundation has their own "official" USB-C power adapter as well (At least, they have it for pre-order). So I doubt it's the highest priority. I can still see this getting fixed in a future revision, but I think it will be a while. It is an issue, but it doesn't make the pi 4 useless.

jws 7y ago
When I saw the official adapter was 5.1 volts I just mentally relabeled that port as “proprietary power port” and got their adapter. They fudged their power supply voltages up on previous models to handle drop in the regulators. I presume that will be an issue on these as well.
agumonkey 7y ago
I see it as an 'exercise left for the reader'
Traster 7y ago
This is going to be a really sticky issue for a consumer. Randomly not working with some subset of USB-C cables is the sort of thing you expect the engineering team to consider - and they missed it. How do you think the average enthusiast is going to figure out that their Pi4 no longer works because of the USB-C cable they're using? At best they'll decide the cable is faulty, use a different cable and probably bin the old one, at worst they'll just come to the conclusion the Pi is bricked and bin it.
- morsch 7y ago
  How do you think the average enthusiast is going to figure out that their Pi4 no longer works because of the USB-C cable they're using? Presumably they're going to search for pi 4 does not power on and get their answer as the first search result[1]. You know, the same way the average enthusiast figures out the other twenty seven roadblocks they stumble on during their RPi project. Not to minimize that it'll be an issue for those people who don't happen to have a compatible charger laying around. [1] For me, at the time of posting: https://hackaday.com/2019/06/28/power-to-the-pi-4-some-chargers-may-not-make-the-grade/ https://hackaday.com/2019/06/28/power-to-the-pi-4-some-charg...

consp 7y ago

I would not be surprised if this is the default in the bcm2711 documentation and they simply took that as guidance.

amelius 7y ago

> The short summary is that bad things (no charging) happens if the CC1 and CC2 pins are shorted together anywhere in a USB-C system that is not an audio accessory. Why should it matter what kind of accessory it is used in? > Each CC gets its own distinct Rd (5.1 kΩ), and it is important that they are distinct. Why? I think this article was not written by an electrical engineer. The reason why this design is inadequate still eludes me. But, RPi should have probably used the reference design, that's clear.

InitialLastName 7y ago
> Why should it matter what kind of accessory it is used in? I suspect you're misunderstanding what they mean by "audio accessory". They don't mean "a standard digital USB device that happens to do audio-related things". USB-C has a special-case allowance to drive analog audio signals through the port (to allow all-analog headphones and such) that has its own CC configuration. >> Each CC gets its own distinct Rd (5.1 kΩ), and it is important that they are distinct. > Why? Because of the above; if the CCs use the same Rd, they're shorted together by definition, which isn't allowed to happen. Especially since the USB-C format uses the CC's to determine plug orientation.
- dTal 7y ago
  >USB-C has a special-case allowance to drive analog audio signals through the port Wat. Just when I think I've heard it all...
  - floatboth 7y ago
    You've seen the Type C - 3.5mm headphone dongles right? They're so tiny and cheap.. did you think they could be active? :)
    - deleted 7y ago
      [deleted]
  - cesarb 7y ago

seaborn63 7y ago

I read it but I have no idea what it meant. I am very interested in getting a Pi4, so can some of you more knowledgeable folks help me understand what this means?

wereHamster 7y ago
The Pi4 does not work with all USB-C chargers. You may be lucky and it will work, or you may be unlucky and it will not work and you will have to buy another USB-C charger (which again may not work). The reason is that the developers of the Pi4 made a mistake while designing the electronic circuit. They tried to design it themselves instead of copying it from the specification.
- JshWright 7y ago
  The other reason for is that the developers of the USB-C specifications left us with a terrible confusing mess where visually identical cables have different capabilities and behaviors.
  - derefr 7y ago
    If it’s confusing, just don’t use it. They could have stuck with a micro-B charger, or a custom charger, and no one would have questioned it. Instead, they decided they were confident enough in their understanding of USB-C to implement it on their device. And they were wrong.
    - JshWright 7y ago
      I said the "other" reason. I am not absolving the RPi team here... The fact that they shipped this reveals significant gaps in their engineering and QA processes. That doesn't change the fact that USB-C is a mess, and that mess contributed to this failure.
    - TremendousJudge 7y ago
      >They could have stuck with a micro-B charger Somebody here said they were running into the maximum rated current for the port >or a custom charger Literally everyone would have complained

crshults 7y ago

Had to fire up Eagle quick and take a look at my latest design (first time using USB-C). Looks like I got lucky this time.

deleted 7y ago
[deleted]

michaelt 7y ago

The fact that no QA team inside of Raspberry Pi’s organization caught this bug indicates they only tested with one kind (the simplest) of USB-C cable. Raspberry Pi, you can do better. I'd say at least 20% of the blame lies with whatever genius decided to have multiple types of USB-C cable I mean, cables already suffer from having A, Type A SuperSpeed, B, B SuperSpeed, Mini-B, Micro-B, Micro-B SuperSpeed, C, and lengths from 10cm to 5m. Who'd expect adding a complete extra dimension of difference to be trouble-free?

ProblemFactory 7y ago
I believe the original plan was the opposite - one port and one cable type that can do everything - 100W of power, 5K video, USB devices, analog audio, Ethernet and more. But it was naive to think that manufacturers will ship a $30 cable for a phone charger when a cheaper hack will do. At least there should have been mandatory color coding of the "full" and "limited" ports and cables, just as USB 3 ports were blue to distinguish them from older versions.
- y4mi 7y ago
  Until cheap knockoffs heard they could charge 4x their normal price by changing the coloring. ... You can't trust the coloring either if you're buying off of Amazon, eBay or any Chinese site like Alibaba
  - Wowfunhappy 7y ago
    Coloring appears to have worked for distinguishing between USB 2 and USB 3, at least in my experience.
    - katbyte 7y ago
      With USB 3 isn’t the other end of the cable usually different as well?
      - deleted 7y ago

_wmd 7y ago

Pretty unfortunate design flaw, and hopefully it can be corrected, but this post is horribly finger-pointy and the tone generally stinks. Would hate to make a mistake while working around this guy Can the link be changed to the apparent source article? It's not as bad. https://www.scorpia.co.uk/2019/06/28/pi4-not-working-with-some-chargers-or-why-you-need-two-cc-resistors/ https://www.scorpia.co.uk/2019/06/28/pi4-not-working-with-so...

MobileVet 7y ago
Seriously. Considering what a cluster the spec is and the budgetary goals for a project like the Pi, this feels really harsh. The focus is on the mistake and how trivial it was without any thought of why or how. Pointing out mistakes can be done without being such a jerk about it.
- joelhaasnoot 7y ago
  They spend months if not years on the design and crank out millions. Getting USB-C right seems like a no-brainer!
  - MobileVet 7y ago
    I highly doubt they spent years on the design... But regardless we all make mistakes. What is a no brainer to you may not be to everyone. Besides, you are fundamentally assuming this was a mistake and not a deliberate design decision. Maybe they prioritized X over following the spec 100%. I may not make that decision, but that doesn’t mean they didn’t.
- arghwhat 7y ago
  This is exactly why the presence of this mistake appears very careless. When you are met with a complicated spec with known issues, do you test more or less? I know which I'd pick, and if they had tested common cables like those from Google or Apple (I'm sure someone has a macbook), they'd see it not work.
- pas 7y ago

zimbatm 7y ago

TIL; there are different types of USB-C cables with functional differences. How do you know what type the cable is? Is is possible to detect it visually?

pixl97 7y ago
You can detect it visually by the sparks and smoke coming out of your device.
- ineedasername 7y ago
  Sure, but what color sparks? In my experience, standard orange sparks mean you just killed a component. Blue sparks mean you just did something very interesting, but not too healthy. Green sparks mean you're scraping thin the boundaries of reality, and Eldritch horrors are looking at you in hunger.
XaspR8d 7y ago
Also curious about differentiation strategies, if anyone has tips. I'm guessing the marketing materials for the cables isn't even sufficient to tell them apart in many cases. It's tempting to build some sort of test rig for this (though I hardly have the background for it)...
- cesarb 7y ago
  I don't have a USB-C device right now to check, but according to https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-class-typec https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-c... there might be some information at /sys/class/typec/<port>-cable
- pault 7y ago
  There are lots of testers on the market, but it's hard to differentiate them and I'm sure many of them are garbage. I need one myself, but I haven't had the time to do the research yet.
ProblemFactory 7y ago

baybal2 7y ago

Usb PD + type C is hard. You have to read specs for days just to get a basic idea of the logic governing the negotiation protocol. I'm waiting for a single chip solution that will take upon the pain of dealing with Type-C for me. Besides the complexity of the spec itself, another "landmine" in dealing with Type C + PD is the divergence of different PD implementations, proprietary extensions from big brands, and... DRMed power supplies along with devices with DRMed PD devices... Yes, the electricity is now copyrighted too.

brandmeyer 7y ago
Common misconception: USB Power Delivery is not what the RPi4 is doing. The base Type-C spec provides the schematic for analog signaling of either a 5V/1.5A or 5V/3A state. USB-PD uses a much more complex digital signaling method across the CC lines, and is its own separate spec.
- baybal2 7y ago
  Yes, it is not a PD. I am talking specifically about the case of doing USB fast charging aka USB PD, which is much, much more complex
  - brandmeyer 7y ago
    The entire USB power situation is complex. Lets see, there's pre-enumeration classic 5V/100mA, post-enumeration 5V/500mA, a host of proprietary signaling methods for additional power, the more or less de-facto BC 1.2 method for extra power, Type-C analog signaling for 5V/1.5A or 5V/3A power, and USB-PD digital signaling. Oh, and there's also Type-C VCONN power in addition to VBUS power. The irony in all this is that Type-C analog signaling was meant to greatly simplify the market situation and UX well above and beyond what happened in the micro-B charger world. And it is simpler. RPi4 just goofed in their implementation.

moonbug 7y ago

Says more about the quality of no-name usb wotsits

gadgetoid 7y ago

Ever since the very first model, sub-par, underrated power supplies have been responsible for a good slice of tech support issues with the Pi. It wouldn't be a real Pi launch without power issues. IIRC the Pi 3B+ was butting up against (if not exceeding) the maximum rated current for the microUSB port, so I believe the switch to USB Type-C is more about picking a port that can handle a 3A@5V supply than a conscious effort to support the dozens and dozens of terrible and near arbitrary USB Type-C supplies on the market (some output 12V with zero negotiation. You know- for giggles). I'd be surprised if they tested with more than a couple of staff phone chargers and their own-brand chargers. I can't imagine the idea of anyone using an expensive power-delivery enabled dock with a thick, 40cm Thunderbolt 3 cable really entered their minds. My advice to anyone buying a Pi 4 would be "Just buy a Pi-branded power-supply. They're inexpensive and guaranteed to work." Granted you might want to save a few bucks and use your phone charger... but then what are you going to use to charge your phone?

DangerousPie 7y ago
> Ever since the very first model, sub-par, underrated power supplies have been responsible for a good slice of tech support issues with the Pi. It wouldn't be a real Pi launch without power issues. Except this time the issue is not with the power supplies by the Pi itself.
- gadgetoid 7y ago
  I think the problem is that people see a USB Type-C port and expect everything with a USB Type-C connector to work in it, which has and never will be the case with USB Type-C connectors. If you think this is bad, go ask PlanetCom what the heck "Pump Express" is and why USB Type-C PD power supplies wont charge their phone ;)
  - jrockway 7y ago
    Nintendo also interpreted the USB Type-C standard interestingly.

fortran77 7y ago

Everything works for me except my Apple charger. I blame Apple.

LIV2 7y ago
The linked article shows how it's due to a design flaw and explains why shitty cheap chargers/cables work but ok
Tepix 7y ago
Wrongly.
jesseb 7y ago
Apple followed the specification, the Pi 4 does not. How is this Apple's fault?

an_d_rew 7y ago

There have been a lot of comments here but I want to leave one specifically to the person or team who designed the Pi’s circuitry: Thank you for working on such an important project and thank you for all the things that you got right. I’m sure that somewhere, someone is feeling a little bit embarrassed and possibly somewhat sheepish over this and… Please don’t let one incident overshadow all the great things that have come from the existence of the Raspberry Pi!

jaclaz 7y ago
I would add - for what it may count - that IMHO there is an issue with the actual USB-C "standard" (not unlike many other standards that have been made by this or that "technical committee" into a large mass of mostly unreadable stuff). The document (that you can find here [0]) is a 27 Mb .zip [0] https://www.usb.org/document-library/usb-type-ctm-cable-and-connector-specification-revision-14-march-29-2019 https://www.usb.org/document-library/usb-type-ctm-cable-and-... inside there are various .pdf files, the most interesting is the one named "USB Type-C Specification Release 1.4 - Redline from 1.3.pdf" , besides highlighting the changes, some minor like changing "existing" to "legacy USB", it makes clear that the matter is complex. The specification, remember only for USB-C connector and cable, is 338 pages, I wouldn't be so hard with someone that missed something in them.
- LaughingMan11 7y ago
  It's one thing if an enthusiast made a mistake putting together a one-off breadboard for a board they're hacking on. But it's entirely a different problem if a professional engineering organization, with a hardware release process, a factory build process, and a QA process didn't read the spec properly and didn't catch this bug. If it's someone's profession to do engineering, don't give them a pass for not being able to follow an industry specification. Engineering is all about following arcane rules in various specs. If it's not USB, then it's Wifi or Bluetooth, or whathaveyou specs, which are all similarly complicated. For what it's worth, the USB spec is complicated, but in this case, there's actually a picture in the USB Type-C Spec you linked to which tells hardware designers exactly how to put together this circuit. They should have just copied it directly instead of going off-script. I wrote about it here, and included the figure from the spec: https://medium.com/@leung.benson/how-to-design-a-proper-usb-c-power-sink-hint-not-the-way-raspberry-pi-4-did-it-f470d7a5910 https://medium.com/@leung.benson/how-to-design-a-proper-usb-...

cesarb 7y ago

There might be yet another issue. As commented by the author of this blog post in the RPi forums (https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=243875#p1492674 https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=2438...): "Also the 5v on the connector is connected directly to the 5v rails. If the pi is powered over the GPIO then the USB-C connector is vbus hot which means it could backfeed devices when using the type C port on the pi as a USB client." That is, when powering the RPi4 through PoE, its USB-C connector is in an invalid configuration: it's powering VBUS when it shouldn't (that is, unlike USB-A where VBUS is always on, IIRC with USB-C it should only be turned on when the CC pins detect that the other side is either a power sink or an adapter which should source power).

londons_explore 7y ago
Backfeeding power is one of those things that is 'technically' a bad idea, but practically damages pretty much nothing.
- TylerWard 7y ago
  Another potential issue here is that if using the Pi as a client with a C-C cable this could confuse the device at the other end meaning it wont connect as it thinks it is being charged (will be seeing if I can get this to occur over the weekend).
  - TylerWard 7y ago
    Have just run this test and it does appear to confuse some USB-C ports (my phone and 3.0 usb-C port on my laptop detect the pi gadget however the 3.1 usb-C port doesn't detect the gadget if the pi is powered by gpio).

chx 7y ago

How does the HN system work when I submitted the exact same URL https://news.ycombinator.com/item?id=20317687 https://news.ycombinator.com/item?id=20317687 five days ago??? We have stickied this on the usbchardware subreddit as well at the time, it's still on the top: https://www.reddit.com/r/UsbCHardware/ https://www.reddit.com/r/UsbCHardware/ We have a nice wiki and if you are still confused about USB C, ask away, we try to help (chances are, I will answer :) ). You will also find a wonderful cornucopia of interesting USB C devices -- not just the usual chargers, power banks and docks but also a toothbrush, a razor, headphones, speakers, video lights, a soldering iron... we like USB C :)

tracker1 7y ago
Just guessing the person that submitted later has significantly more karma or popularity. It seems to happen quite a bit. There's also time of day to consider, it's possible this made it in when more people are browsing by newest and upvoted pretty early.
- glenneroo 7y ago
  chx has 8000+ karma whereas OP has ~600, so scratch that as a possible explanation. I would also guess it mainly depends on the time of day.
- chx 7y ago
  The question rather is, why would the system allow the same URL to be submitted twice. In the past when I tried to submit something already in, I was redirected to the existing post and my submissions was converted into an upvote.
  - hombre_fatal 7y ago
    A five-day-old HN submission is effectively dead. Would make sense if the behavior you describe only happens to dupe urls within 24hr of each other if the first one hit a certain threshold of traction. Else makes more sense to allow the dupe submission to give it another shot.
  - 7y ago

w0mbat 7y ago

There's a project management lesson here. Raspberry Pi 4 was planned for 2020, but the Broadcom SOC went final much sooner than expected, so they shipped the Pi 4 this year. This sounds like a great thing, but the earlier release meant that the board as a whole spent less time being used internally before release, and they didn't have the time to shake out bugs like this. The lesson: when you move to a faster release cadence, you need to be more rigorous about QA because you have less time to find problems before release.

geekamongus 7y ago

I just wish I could find a 4GB Pi 4 in stock/for sale so that I could even have this problem.

sbisson 7y ago
I ordered one yesterday from the Pi Hut here in the UK. It shipped today...

Scuds 7y ago

Odroid, Latte Panda, Pine, and others went with dedicated tried and true barrel jacks. I appreciate re-using the same microusb cables and chargers for my iPhone and headset charger for my Pi3, and not having to handle Yet Another Wall Wart, but barrel jacks would have sidestepped this whole issue. Were they hoping to have users use a single cable deliver power and data over a single cable usb just like a pi zero w? https://desertbot.io/blog/ssh-into-pi-zero-over-usb https://desertbot.io/blog/ssh-into-pi-zero-over-usb God DAMN I hope this doesn't turn into a recall.

Narishma 7y ago
Why would this turn into a recall? AFAIU, this is just an inconvenience, not a show-stopper since it only affects high-end cables.

mrlambchop 7y ago

The Pi people are good folk - all that is needed is to run the USB 3 conformance tests and report back the results (both as USB PD sink and source). Better to know the knowns than have a enthusiastic fan base find them and we get into discussions like this! I'd also recommend they put up a compatibility table of power supplies on their website in time - probably cables as well! Its a good opportunity to collaborate with the Google engineer who has been spending his non-core hours on the USB-C madness.