HAA Infra Red

Since version 1.5.0 HAA has been able to control infra-red (IR) devices. In order to do this the HAA accessory must have an infra-red transmitter.

Examples of devices that have infra-red transmitters are:

Put some examples here

Alternatively look at some examples of the Web of how to add an IR transmitter to an accessory.

Put some web links here

To understand more about infra-red transmissions and how they are used to control devices around the home refer to the following sites for more information:

• Remote Central
• Consumer IR

How HAA supports infra-red control

IR commands consist of groups of infra-red light pulses sent sequentially. These pulses are split into marks and spaces. With marks being the period where infra-red light is transmitted and spaces being the period where no infra-red light is transmitted. A mark consists of an alternating burst of infra-red light where the light is pulsed on & off at a particular frequency. The most common frequency used by IR transmitters is 38KHz.

Manufacturers often define an IR protocol for their equipment. This protocol defines what a mark consists of and the duration of marks & spaces. Sony TV remotes use the Sony Control-S protocol for instance. For more details on IR data formats checkout this Vishay document or this IR Remote Control Theory document.

HAA supports IR control by enabling the specification of either RAW or Protocol formats for the data to be transmitted. A RAW format defines the code to send as an exact replica of a captured signal. An HAA IR Capture Tool is provided for enabling the capture of remote control codes using an IR receiver hooked up to an HAA accessory. A Protocol format defines the infra-red sequence exactly how the manufacturer intended the codes to be sent.

RAW Mode

In RAW mode the IR codes are sent exactly as captured using the HAA IR Capture Tool.

Transmitting the raw captured data is not recommended because you are using a copy of the signal and the quality of the captured signal may be degraded. Use it only if you are unable to decipher the protocol being used by the equipment. RAW mode also uses a lot more flash storage to hold the definition of the codes, requiring 2 characters for each mark or space sequence.

Below is a sample output from using the HAA IR Capture Tool. The table shows the sequential codes that have been captured by the tool.

In order to re-transmit these codes using RAW mode the numeric values need to be translated into a RAW code string. This can be done using the IR Encoder Table. From the table you can convert the integer code stream into a series of HAA RAW codes. Round the integers output by the IR Capture Tool to the nearest 0 or 5 and then find the value in the N column of the IR Encoder Table. The corresponding value in the C column can then be used to create a RAW code sequence to be transmitted by your HAA accessory.

In the above table the RAW code string can be constructed as follows:

• The integer + 3550 is represented by the code Ht
• The integer -1677, rounded down to 1675, is represented by the code DC
• The integer + 500 is represented by the code AQ
• The integer - 362, rounded down to - 360 is represented by the code 0= etc...

The RAW code string can then be constructed as "w" : "HtDCAQ0=A5B>AP0=AR0=AR0=AR0=AR0=AR0=AR0=AR0?AR0A50=AR0ARCDAK0=AR0=AR0=AR0=AR0=AR0=AR0?AR0?AR0=ARB>AQ0=A50=AR0=AR0-AK0-AL0=AR0=AR0=AR0>AP0?ARCDAKB>APB>APB>AP0=AR0=ARB>AP0?ARCDAKCDAKC0APB>AP0?ARCDAK"

Note: see how long the string becomes when using RAW codes.

Protocol Mode

TBD