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Is a hi-speed usb hid compliant device possible?


#1

Hi,
I am working a project that requires me to send data into my cerberino quicly, ie hi-speed usb rates.

Is this possible with the standard usb clientcode? Or is that lo-speed?

If not, is there any way to do it?
Thanks! :slight_smile:


#2

What speed do you need?


#3

The more interesting question here would be: How fast can a Cerb process the data.
I’m nut sure about the low/high/super speed thingies, but if I remember right, the G120 can not reach the 480MBits of USB 2.0. If I had to guess it’s more like an USB 1.1 speed.


#4

@ Reinhard Ostermeier - correct plus these devices do much with the data before it reaches the application. If you do things like stream video then things need to be handled quickly, maybe inside the isr. This is the only way we could get usb webcams to work.


#5

Hi,
Thanks for the replies.

My project has a cerberino sitting between a PC (Usb Link) and a old digital synth (GPIO)

I have a virtual midi port on the PC, and it is sending Midi clock pulse (which are just serial messages) down the USB line to the cerberino.
I use the cerberino to compute the time between clock pulses and then re-generate a clock which I send to the synth.

So, it’s not that I need to send a lot of data of the USB, I just want it’s timing to be as accurate as possible. So, I assumed if it was using a hi-speed link, that would be better. Or put another way, the faster the link, the more accurate by clock timing would be.

Thanks again
Guy


#6

You can’t get accurate timing with netmf. It is suited for non real-time needs.


#7

Arghh… ok.

I wonder if I could do that part in RLP?

ie. intercept the USB message some how? or the when the message comes in, get it to call a RLP routine which could do the timing code?

Or I am just wasting my time trying to do any real-time stuff? If hope note, as C# really is my prefered language!


#8

Ok, looks like I’ll try another route.

Thanks for all the feedback, much appreciated :clap:


#9

@ gwpt - USB on the whole is not intended nor can it do time sensitive operations. This is how it was designed (I can’t recall where I read that but I happened upon that fact; firewire however…). I have a USB MIDI device (a M-Audio which I use with Reason), and I haven’t had timing problems with that; and it’s a usb 1.1 device.