Jose Colmenares wrote: > 128000 bytes per second for a 1000Hz frequency (which the device > can give). 128000 bytes per second is a lot less than the 480 Mbps > that USB 2 gives. That's what's killing me. I don't think you have written that you have a particular latency requirement, but Greg seems to assume that you want to approach zero latency, which indeed USB is not at all capable of. USB is a high throughput and (relatively) high latency bus. Exactly how high throughput and how high latency depends completely on what protocol the USB device implements. USB offers a wide range of communications building blocks, and each device implements some particular protocol with a combination of them. Many devices unfortunately implement very inefficient protocols. Greg's advice to drive this device from userspace is very good - take a look at libserialport for a good start: http://sigrok.org/wiki/Libserialport https://github.com/martinling/libserialport //Peter -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
