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Story of Idiots: Raspberry Pi
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  • eatstoomuchjameatstoomuchjam

    Looks like price is expected to be from $63-79. Not bad!

    It's unfortunate that they didn't go USB-C for power, though. Maybe in the next iteration...

  • Vitaliy_KiselevVitaliy_Kiselev

    @eatstoomuchjam

    What is the advantage of using USB-C for power?

    Thing is very fragile, does not allow cable to turn and very hard to impossible to repair only with soldering iron.

  • eatstoomuchjameatstoomuchjam

    @Vitaliy_Kisilev Because USB-C is super common, can carry enough power, and it's much easier to replace the cable or power brick when broken. Also, when traveling internationally, it's easy to buy a USB wall plug which is nice and small vs having to carry a series of large plug adapters.

  • Vitaliy_KiselevVitaliy_Kiselev

    @eatstoomuchjam

    Round plug type power connectors are more common outside smartphone industry. They are much better for the task. Such plug price for company making wires and small PSU is around 10x cheaper compared to good USB-C connector.

    It is extremely easy to replace power supply, as it is common voltage and usually all of them use 1-2 common sizes of plugs.

    And no, USB-C can carry only 2.5-3A at 5V as normal, most Chinese wires you can find at airports are best kept at 1A and below as they use extra thin alu wires (cheap USB-C Chinese cables are much worse than older Micro USB cheap ones).

    Cables that can carry more power require special chip to enable such mode and separate extra wires (90% of cables lack this).

  • eatstoomuchjameatstoomuchjam

    @Vitaliy_Kiselev One of the reasons that the Pi is popular is that it can be powered off of USB Micro-B. Since this board costs about 2-3x the price of the latest Raspberry Pi, it seems like there should be enough budget to bulid a good USB connector.

    And while you may think it's easy to figure out the right type of barrel connector at the right voltage to replace the one that board needs, lots of others will find it opaque - vs a USB connector, which whether it needs extra leads or not, is still generally a whole lot easier to find.

  • Vitaliy_KiselevVitaliy_Kiselev

    @eatstoomuchjam

    Again, USB connectors are WRONG way to power such devices. It can look like simple and easy way for beginner, but I am not sure it must be done even for them as target audience. As such connectors, including USB-C, are prone to failure, heating, becoming real fire hazards.

    For smartphones and notes most safe way is to use MagSafe type connectors. And Apple knows this perfectly, my sources told that they replaced it by USB-C type connectors as number of catastrophic drops increases a lot - hence more service income and new sales.

    Btw, it is lot of magnet type USB cables, including ones for only power, but most of them are 1A.

    As for barrel connectors:

    image

    It is best of them all - developed by real engineers and user interface designers. Easy to plug, easy to pull out, usage of large soft resin inside female part.

    sa7027.jpg
    325 x 589 - 23K
  • eatstoomuchjameatstoomuchjam

    Let me know when you're ready to come back to the real world where lots of devices are currently using USB-C to deliver far more power than is needed by this small SBC and are not bursting into flame. :)

  • Vitaliy_KiselevVitaliy_Kiselev

    @eatstoomuchjam

    Unfortunately I saw whole apartments destroyed by bad micro usb. Connector shorted out, charger overheated as result and after 2-3 hours fire started.

    Also suggest to visit any high volume notebook and smartphones repair service and ask few questions about connectors, common issues and how easy it is to repair or replace. Reason why all of the sudden many companies went for USB-C is exactly feedback telling them that such device lives much less and repairs bring much more money (connector repairs are almost always excluded from warranty).

    Around 50% of smartphone devices using USB-C never use more than 5W (as they use cheap chargers and cheap horrible wires). Next 30% are using up to 10W. And only remaining use from 15 to 30W (3A or 12V variants) with various quick charge methods.

    Latest Pi model uses 6W, so it is not issue of power, it is issue of reliability.

    Finding good safe power supply with USB-C while seems simple is really hard, it is area of extreme competition and huge number of fake remarked products.

  • Vitaliy_KiselevVitaliy_Kiselev

    The microUSB connector was only originally designed to provide 1.8A, and even though that is an old standard and you can find chargers that perform just fine at more than that, so many people try to reuse old phone 1A chargers or buy cheap adaptors online to power their Raspberry Pis. The Pi is a computer, it requires a good quality, stable power supply that provides a stable 5V at the input and is capable of providing 2.5A. Not only the transformer needs to be decent, but also the connection needs to be good (or there will be a voltage drop) but more importantly, the cable needs to be good, or there will be a big drop along it. Bad cables are even more typical to find than unstable voltage supplies, so please, use a good cable, maybe a 20AWG or similar, or just get the official power supply. The take away is that not any USB charger is going to work properly, even if it is 2.5A 5V.

    Add this to was we saw in the last section and we can begin to see the big picture. Most users are running their devices undervolted, and the GPU is hiding this from them, so they are actually running underclocked at 600MHz, almost as bad as the original ARMv6 pi.

    https://ownyourbits.com/2019/02/02/whats-wrong-with-the-raspberry-pi/

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