HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
Comment
Christian Légaré
User Rank
Blogger
Re: Nov 28 - Day 3: Understanding the USB Protocol
Christian Légaré   11/28/2012 3:06:12 PM
NO RATINGS
Can you achieve a overall sampling rate of 100Hz for up to 32 USB FS devices connected, when the payload is 4 floats per device. Could this be achieve with HID/Joystick type class, or should I go directly with a custom class??

 

We will have to do the math. First, HID is the right class to use, because it is peioritized by the Host.

(Your 4 floats are 64 bits each? this would mean 32 bytes per transfer)

Second, let's look at the Full Spee table for Interrupt transfer using 32 bytes transfer and see the maximum throughput.

 

At 100Hz, that would mean once every 10 frames. Or stated otherwise, that would mean you can server 3.2 device per frame and have covers the 32 devices in 10 frames.



Partner Zone
Latest Analysis
After more than a century of dedicated service, metals are still upping their game and delivering lighter, stronger bodies and frames to the auto industry.
Suppliers are chipping away at the dominance of the venerable polyvinyl chloride (PVC) electrical cable with rollouts of new environmentally safe, recyclable alternatives.
Most machine design engineers will survey existing component manufacturers for standard linear guide products, limiting what they can do with their designs. Using extruded aluminum profile guides can customize machine designs while shrinking the bill of materials.
The new entity, Celera Motion, will continue to sell Applimotion and MicroE kit-style product lines and leverage their combined integrated assembly expertise.
Practically all electronic devices today contain metals that may be coming from conflict-ravaged African countries. And political pressures will increasingly influence how these minerals are sourced and used in products.
More:Blogs|News
Design News Webinar Series
6/25/2015 11:00 a.m. California / 2:00 p.m. New York
6/24/2015 11:00 a.m. California / 2:00 p.m. New York
6/11/2015 11:00 a.m. California / 2:00 p.m. New York
8/13/2015 11:00 a.m. California / 2:00 p.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Aug 3 - 7, Developing, Testing, and Troubleshooting IPv4 and IPv6 Using Wireshark
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6 |  7


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Course August 25-27:
Sponsored by Stratasys
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2015 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service