Bluetooth Low Energy The Developers Handbook – Robin Heydon

Figure 8–18. HCI initiating a connection to a device 8.6.3. Canceling Initiating a Connection Sometimes a connection is initiated to a device that is not responding, probably because it is nowhere near the initiating device, and the host wants to cancel this connection request to do something else. In this example, which is shown in Figure 8–19, the host uses the LE Create Connection command to attempt to connect to a specific device.

This also works for initiating a connection to a white list. When the host wants to cancel the initiating of this connection, it sends an LE Create Connection Cancel command to the controller that responds with a Command Complete event for the cancel command as well as an LE Connection Complete event for the initial LE Create Connection command.

It is important to complete all commands, and the LE Create Connection command is completed with the LE Connection Complete event, regardless of whether the connection was created. Figure 8–19. Canceling a connection initiation It should be noted that there is a race condition here. It is possible for the host to send the LE Create Connection Cancel command to the controller at approximately the same time that the controller sends a CONNECT_REQ packet to the peer device but before the LE Connection Complete event is sent to the host to notify it of the new connection.

In this condition, the LE Create Connection Cancel command will be completed by using the Command Complete event, but the LE Connection Complete event will be sent up to the host reporting the new connection that has been created. It is possible, therefore, to have created a valid connection even when trying to cancel this very same connection.

8.7.

Upper Saddle River, NJ • Boston • Indianapolis • San Francisco New York • Toronto • Montreal • London • Munich • Paris • Madrid Capetown • Sydney • Tokyo • Singapore • Mexico City 1kitap1.com/en Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book, and the publisher was aware of a trademark claim, the designations have been printed with initial capital letters or in all capitals.

The author and publisher have taken care in the preparation of this book, but make no expressed or implied warranty of any kind and assume no responsibility for errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of the use of the information or programs contained herein. The publisher offers excellent discounts on this book when ordered in quantity for bulk purchases or special sales, which may include electronic versions and/or custom covers and content particular to your business, training goals, marketing focus, and branding interests.

For more information, please contact: U.S. Corporate and Government Sales (800) 382-3419 [email protected] For sales outside the United States please contact: International Sales [email protected] Visit us on the Web: informit.com/ph Cataloging-in-Publication Data is on file with the Library of Congress. Copyright © 2013 Pearson Education, Inc. All rights reserved. Printed in the United States of America. This publication is protected by copyright, and permission must be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise.

To obtain permission to use material from this work, please submit a written request to Pearson Education, Inc., Permissions Department, One Lake Street, Upper Saddle River, New Jersey 07458, or you may fax your request to (201) 236-3290. ISBN-13: 978-0-13-288836-3 ISBN-10: 0-13-288836-X Text printed in the United States on recycled paper at RR Donnelley in Crawfordsville, Indiana. First printing, October 2012 Executive Editor Bernard Goodwin Managing Editor John Fuller Project Editor Elizabeth Ryan Copy Editor Bob Russell Indexer Jack Lewis Proofreader Christine Clark Cover Designer Gary Adair Compositor LaurelTech 1kitap1.com/en This book is dedicated to Katherine.

—Robin xxx 1kitap1.com/en Contents Preface Acknowledgments About the Author Part I Overview Chapter 1 What Is Bluetooth Low Energy?

This is a short excerpt from the opening of “” by Unknown, quoted for review and introduction purposes. All rights belong to the copyright holders.

Book Information

• Unique ID: 0c88859c3ae6fa45
• File Extension: .pdf
• File Size: 6,462,968 bytes (6.164 MB)
• Title: –
• Author: Unknown
• ISBN: 9780132888363, 013288836X
• Pages: 454
• Language: English (en)

Reading & Word Statistics

• Estimated Reading Time: 567.4 minutes
• Total Words: 113,480
• Total Characters: 703,360
• Average Words per Page: 249.96
• Average Characters per Page: 1549.25

Most Frequent Words

device (1086), data (818), connection (643), service (628), devices (585), used (559), packet (487), advertising (471), value (461), bluetooth (443), attribute (434), characteristic (406), state (398), request (396), low (392), services (382), one (368), energy (357), also (345), information (337), client (335), using (332), time (329), command (311), link (303), packets (302), host (292), bit (285), controller (282), read (265), layer (260), use (258), slave (253), two (250), example (245), figure (238), channel (235), possible (231), therefore (225), sent (224), protocol (217), power (217), response (217), set (211), peripheral (211), type (205), server (203), address (199), number (196), test (191), encryption (191), event (181), another (178), central (176), frequency (175), mode (174), means (169), radio (168), procedure (168), master (168), write (166), hci (161), key (160), channels (157), single (157), control (151), send (151), different (148), interface (146), security (146), first (140), defined (139), need (138), values (137), between (135), profile (134), message (133), handle (133), design (130), characteristics (126), list (126), attributes (125), behavior (125), new (123), user (122), parameters (121), application (119), transmit (119), many (118), access (118), battery (118), typically (117), received (117), required (115), error (112), scanning (110), given (109), primary (108), next (108), see (108).

PDF Download