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A Guide to online information about:

IrDA

by Benjamin Day

The original IrDA specification provided for a maximum data rate of 115.2 kbps, but IrDA has been extended to greater speeds. Currently, IrDA 1.1 supports speeds up to 4 Mbps and work is under way to increase speeds to 16 and possibly 32 Mbps. IrDA does not limit itself to just the physical specification either. IrDA takes a layered protocol approach specifying several layers of protocols including IrPHY (physical layer), IrLAP (link access protocol) and IrLMP (link managment protocol). The specification also groups devices into two classes: IrDA Data and IrDA Control. IrDA Data covers data that may need to transport large amounts of data devices such as printers and digital cameras. And IrDA Control covers control devices including mice, keyboards, game controllers, and so on.

Beyond the required protocol layers.( IrPHY, IrLAP, and IrLMP), there are numerous optional protocols that help with various kinds of applications. For example, the IrTran-p protocol is commonly used in digital cameras for transferring pictures back to a host computer.

Chip Vendors

A variety of companies now offer integrated IrDA transceiver solutions that combine an infrared emitting diode and detector pair with a transceiver on a single chip module. Depending on the processor or microcontroller you are using, you may also need an IrDA controller. I have provided a list of a few vendors of both IrDA transceivers and controllers.

IrDA Transceivers from HP come in a variety including 3.3 V, low power supporting both IrDA 1.0 and 1.1.

HP has quite a few app notes on several IrDA-related topics, including an applications note on European safety regulatory standards. Although the applications note is geared specifically toward HP IrDA products, you may find some of this information to be a helpful starting point. You'll also find HP's IR Data Link Design Guide quite useful.

HP also offers evaluation and development kits as well as a reference design kit. The AmbER reference design kit features an AMD Am186ER microcontroller coupled with HP's HSDL-1001 IrDA transceiver. The reference design kit includes application software that can send a page to a laser printer via the IrDA port.

Infineon Technologies offers a full range of IrDA transceivers including 115 kbps, 1 Mbps, and 4 Mbps. Soon they will also offer a 16-Mbps transciever!

National offers a UART that includes an onboard IrDA controller. There is also an evaluation board available for their UART. If you are planning to put a UART in your design, then this is a great solution. Also, if you want to support the full 4-Mbps specification a good UART is essential.

NEC also offers IrDA transceivers for both IrDA 1.0 and IrDA 1.1.

Texas Instruments offers a range of products including IrDA transceivers, IrDA controllers, hybrid UART/IrDA controllers and an EVM. Check out their product selection guide. TI also offers software drivers, some of which include source code.

Vishay Telefunken offers several IrDA transceivers to choose from as well as a nice 16-pin IrDA controller – the TOIM3000 – it offers a simple two-chip solution that you can connect directly to any microcontroller with a serial port. The Vishay Telefunken web page also contains some PDF files with recommended circuits and reference designs.

Organizations

The Infrared Data Association provides a Technical Summary of "IrDA Data" and "IrDA Control" that outlines the differences between the two and the mandatory protocols required by each. The Technical Summary page also describes the Infrared Data Association's Beaming IR logo licensing program for compliant devices.

The Infrared Data Association offers specifications for most if not all of the protocols being used today:

The Infrared Data Association offers some useful guideline documents including their Implementation Guide, Protocol Layer Test Guidelines, and their Physical Layer Test Guidelines.

Software

ACTiSYS Corp is a supplier of infrared wireless IrDA protocol software and adapters for 115.2 kbps and 4 Mbps, since 1990. The ACTiSYS web site IrDA tutorial page includes useful information on system integration and testing, as well as a white paper and a feature article from Wireless Systems Design, May 1996.

Counterpoint Systems

Counterpoint Systems offers a variety of protocol software with support for popular RTOS including pSOS and Tornado.

EMBEDnet offers IrDA-compliant communications software for portable devices. EMBEDnet's IrPro SDK comes with primary and secondary protocol stacks which support IrLAP, IrLMP, IAS, IrLPT, TinyTP, and IrCOMM. Optional protcols OBEX, IrCOMM, IrMC, IrTran-p, IrLan, and Ultra are also available.

If you would like to add any information on this topic or request a
specific topic to be covered, contact Benjamin Day.

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