I noticed in the article “Ubuntu 24.04 Runs On The World’s First Credit-Card-Size RISC-V SBC”
the statement “USB 2.0 ports don’t work, as Linux kernel 6.8 doesn’t have support for those”.
I have not found any confirmation of this, eg The Linux-USB Host Side API — The Linux Kernel documentation mentions USB 2 as legacy implying it is still supported.
Wanting to improve my knowledge of USB interfaces I looked at
where I found that
USB 2.0 is the older “high speed” standard used in type A connector with white or black inserts as in older USB memory sticks, PC and laptop connectors, micro-B connector as used in older mobile phones (not iPhone) and type-B connectors as used in external HDD enclosures, printers, older cameras etc.
USB 3.0, 3.1 is the super speed standard as found in the type A connector with blue inserts and in type C connectors.
If USB 2.0 is not supported in Ubuntu 24.04 then either we do not use Ubuntu 24.04 and derivatives or we buy new equipment supporting USB 3.0, 3.1! What have other users of Ubuntu and derivatives 24.04 found?
I would go with Neville that its just the risc machines that may have this limit. Not come across any problems connecting any version of usb to any linux box, except speed but for most users copy between different devices you hardly notice that. I have a usb1 camera and that works fine transfering photos even plugged in to a usb 3 port.
New computers are now only coming with usb C and in some cases only one of them which is a different problem when you want mouse, external drive no where to plug it in without a multi port box
This terminology REALLY grinds my gears, and gets my goat!
That SBC is NOT “credit card sized” - that’s hyperbole - just about the only “Credit-Card-Size” SBC is the Pi Zero series - and the the Pi Zero 2W packs quite a punch! (and yeah - I know there are competing SBC with similar form factor as the Pi Zero - e.g. even the NTC C.H.I.P. was that form factor).
I’d like to try RISC-V - dunno when… No USB 2 support? WTF? What about USB 1.1? Keyboards and mouses? Maybe I’ll give it a miss then… Don’t wanna find out the hard way ($$$).
Thanks for all the comments. It’s surprising that the Linux-USB Host Side API document is not clearer on which USB versions are supported. As @nevj says we would like to be sure.
Type A - blue insert to type C adaptors are readily available and work with super speed USB 3.0 3.1 since extra signals used to synchronise data for the super speed standard are common to both connectors. A type A-blue insert USB port will work with the earlier type connectors since the extra signals are ignored. Not sure if a type C connector would work with a USB 2 standard signal even if such a combination could be found.
Yes , I bought a USB-c to USB-A (both sides male type)adaptor from Aliexpress , with 10Gbps and 120W notification . The plastic insert of the USB-A side is red coloured.
I know the USB specifications, but with the need for more power via USB, especially for charging smartphones, there have been more colors.
One example that stunned me: the specifications for the USB C plug of generation 3.1 for power supply are 240W (48V, 5A) and we need to have a reliable cable that can handle that power, otherwise we’ll never have the maximum power of 240W.
Gone are the days when USB power was 5V and, if you were lucky, 500mA.
Sorry for the off-topic, but I just wanted to mention a plug that’s used for everything, even transmitting data (excuse the irony).
Hi Neville,
No, only if there is an electronic malfunction.
Anything that isn’t standard USB power is negotiated between devices and/or chargers, for example, one of the protocols is PD (Power Delivery) or PPS (Programmable Power Supply), and the initial normal power supply for these devices is always standard USB power.
You may have seen USB chargers that say “Fast Charging”, for phones that use fast charging technology, but if you plug in a “normal” charger, the phone will also charge, it just takes longer to charge and vice versa, you can connect a fast charge charger to a device with standard USB power and the charger will work just like a standard charger.
I was just getting into the conversation because of the colors of the plugs.
If you’re interested in a general understanding of how PD works, here’s a link:
Thanks jorge down a new line…
Perhaps that explains why one tablet can connect to a tv and others not, never thought about power levels just thought connection ?
To make sure that the TV’s USB doesn’t supply enough power for the other devices, as it used to (does(?!)) with some laptops that USB supply a maximum of 500mA, fully charge the devices that don’t work with the TV and.
Once they’re fully charged, connect them to the TV.
If they don’t work, it could be an incompatibility problem between systems, programs, etc., which is another headache…
