Bluetooth™ modules

...for use with mobile robots...

Introduction

Because I thing Bluetooth is a very useful and easy technology for applications in the field of mobile robotics, I published this page in the hope it might help other guys to make their choice by comparing available modules rapidily. You are very welcome to help maintaining this page, by just sending me an email. Also let me know if you use this technology in one of your projects, I will add your web page on this page.

Information on some existing modules

Have also a look at this page for an updated list of qualified modules or this one for a list of modules based on CSR chip.

Please note that the information on this page is only for rough comparison and may be erroneous or not up-to-date. The rows in blue indicate the modules we have tested or are currenlty tested at LIS.

FAQs

> What is the range of the Bluetooth modules?

Class 2 BT modules have a specified range of 10 m but can easily reach 25 m in indoor enironment. Class 1 BT modules have a specified range of 100 m but I never tested one of them.

> Any good papers to read about Bluetooth?

I don't know any scientific paper about Bluetooth. A useful document for developing a wireless module is the BT core specs that you can find on https://www.bluetooth.org/spec/ (read especially H4 and H1 in the appendixes).

> Any development kits?

Well, they exist but are quite expensive and not really needed if the module you plan to buy is configured by default in HCI/H4 mode (see BT specs) and you want to use the serial (RS232) communication mode. Now, it's even easier with the new "transparent RS232" modules (such as LMX9820A), which automatically enables a virtual serial port.

> BT v1.1 specifications state that Bluetooth hardware consists of an anolog part (Bluetooth radio) and a digital part (Host Controller). So, to establish a point-to-point connection, will I need to purchase two chips?

No. Bluetooth modules usually contain both chips (radio & host controller), included the HCI software (you don’t need to program it). The only thing you have to connect is an antenna, which can be quite simple. To sum up, the BT module is ready to be connected to your RS232 port (with a MAX232 for logic level translation, of course) and to be talked to, using commands specified in H1. Note that new modules such as LMX9820A are even simpler in the sense that they automatically enables a virtual serial port. No need for implementing the HCI protocol anymore.

Useful links

• BTNode an open source and harware development kit from ETHZ: http://www.tik.ee.ethz.ch/~beutel/btnode.html
• A nice online Bluetooth tutorial: http://www.palowireless.com/infotooth/
• Bluetooth drivers:
  • Open source, for Linux: http://sourceforge.net/projects/openbt
  • Official Linux Bluetooth protocol stack: http://bluez.sourceforge.net/
  • BlueDrekar: IBM's stack for Linux (not open source): www.alphaWorks.ibm.com/tech/bluedrekar
  • BlueHoc: an open source Bluetooth simulator: http://www-124.ibm.com/developerworks/opensource/bluehoc/tutorial/docpage.html
  • For a microcontroller: http://www.inf.ethz.ch/~kasten/research/bathtub/bluetooth/

Some applications in mobile robotics

• Bio-inspired Vision-based Flying Robots: http://phd.zuff.info
• Low-cost Bluetooth communication for autonomous mini-robots: http://wwwhni.uni-paderborn.de/sct/projekte/khepera_bluetooth_modul/index_e.php3
• Remote control of robots (Murata): http://www.murata.com/ninfo/nr0191e.html
• Sony Debuts Aibo Pet Robots That ´Communicate via Bluetooth: http://www.wirelesssoftware.info/show1news.php/279.html
• Gridswarms, a project about swarming airborne robots (University of Essex) : http://gridswarms.essex.ac.uk/
• A Bluetooth module (eb500) for robotics that has a fully embedded stack including SPP and is controlled through a simple serial command set. Available for purchase through Parallax or ZEKO. See also the author's web site: http://robotics.fullthrottle.com/.
• Yet another Bluetooth module that is readily interfaceable with micro's and the basic stamp; see also the range of autonomous robots that use this modules: http://merlinsystemscorp.co.uk/live/411.0.html.

Published: 03.11.02    Last update: 06.02.2006