On 1/17/23 07:08, Rich Shepard wrote:
On Mon, 16 Jan 2023, Ben Koenig wrote:
That's probably fine. My rule of thumb is to not PLUG higher end hubs
into
lower end ports. e.g. a bunch of USB 3.0 devices in a hub that
connects to
a USB 2.0 host.
The Sabrent HB-7B3C provides 900mA to each USB port. I assume that's not
what the webcam and headphones draw. Just sent a message to Focusrite
asking
how much power the Scarlett Solo Gen 3 draws.
Sorry, I haven't been following this thread too closely, but if this is a
device you already own, you can look this up yourself. First use lsusb
to find the vendor and product ID values for the USB device of interest.
Then use lsusb again to get more information about the device.
Here I've chosen to find the current used by my scanner.
$ lsusb
Bus 002 Device 005: ID 046d:c404 Logitech, Inc. TrackMan Wheel
Bus 002 Device 004: ID 0472:0065 Chicony Electronics Co., Ltd PFU-65 Keyboard
[Chicony]
Bus 002 Device 003: ID 0472:0065 Chicony Electronics Co., Ltd PFU-65 Keyboard
[Chicony]
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 007: ID 051d:0002 American Power Conversion Uninterruptible
Power Supply
Bus 001 Device 005: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle
(HCI mode)
Bus 001 Device 004: ID 04a9:220d Canon, Inc. CanoScan N670U/N676U/LiDE 20
Bus 001 Device 014: ID 0403:6001 Future Technology Devices International, Ltd
FT232 Serial (UART) IC
Bus 001 Device 009: ID 1d50:6018 OpenMoko, Inc. Black Magic Debug Probe
(Application)
Bus 001 Device 008: ID 1a40:0201 Terminus Technology Inc. FE 2.1 7-port Hub
Bus 001 Device 011: ID 1679:2001 Total Phase Beagle Protocol Analyzer
Bus 001 Device 003: ID 1a40:0201 Terminus Technology Inc. FE 2.1 7-port Hub
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
$ lsusb -v -d 04a9:220d | egrep 'iProduct|MaxPower'
iProduct 2 CanoScan
MaxPower 500mA
My scanner draws a max of 500 mA, assuming the manufacturer hasn't lied
when generating the data for the device descriptors. Since the units are
mA, MaxPower is a misnomer. Actual max power would be 2.5W.
Note that everything above doesn't necessarily apply if USB C Power Delivery
is being used. With power delivery, the voltage is no longer necessarily
5V. I'm not sure how the descriptors change in order to accommodate this.
galen
--
Galen Seitz
[email protected]
