[ltp] OT: usb data capture hardware?

[Bert Haskins]

Richard Neill wrote:

> Dear All,
>
> Please excuse this being slightly off-topic: I thought someone here 
> may have experience of what I'm trying to do.
>
> Basically, I have an astrophysics sensor system which generates a 
> 16-bit wide output (from an ADC), with a rising-edge clock every time 
> the output has changed.  The data rate is somewhere between 1-5 MHz, 
> and I need to get this into a computer.

Does it have to be a laptop?

>
> So far:
>
>   1)  It's too fast for a parallel port (unfortunately - or it 

That's only true if you are stuck with running under a GUI.
Using right to the metal machine code the limit would be higher than 5MHz.


>
>       would be ideal)
>
>   2)  The FTDI chip system, such as the DLP-245M is nearly ideal:
>       it implements a parallel port over USB, and has pre-existing
>       GPL drivers - but it is only USB 1.1, so too slow.
>
>   3)  The current solution I've been fighting with is a QuickUSB Module,
>       for which we have reverse-engineered drivers, but it's pretty
>       ghastly, and not reliable.
>
>
> So, any Ideas?

Check with National instruments, I think that they have some
PCI hosted parallel interface boards that should be good to above 30MHz.
Once again, you are looking at custom software, but National just might 
have that
available.

I used to do control systems for three axis machine tools that used a 
single 8088
and I will have to plead guilty to "borrowing" some code from Linux .9( 
something ).


>
>
>
> Thanks very much for your help,
>
> Richard