Research into infrared

The idea of the project is based around the control of devices via a PC – the main goals are to make it as cheap, modular, accessible and physically small as possible.

I plan to cover various methods of control but have started with infrared control and aim to focus on this then, time permitting, expand the system at a later date – infrared should, in theory, be one of the easier and simplest methods of communication although it requires hardware that isn’t usually found within a standard PC.

I’ve been researching products manufactured by the big names in control systems, such as Extron, AMX and Crestron which all cater for multiple infrared emitters and have different approaches to learning new codes via a receiver.

I should point out that I’m basing the requirement for multiple transmitters on my past experience of co-designing, installing / configuring and programming 6 major lecture theatres at my place of work at a reasonably sized UK University. Our preference was to control everything over IP as this allows for greater flexibility, ease of configuration and direct remote access. Where products didn’t provide IP control, we settled for RS-232 and as a last resort infrared.
Most equipment fell into the first two categories but some (products we considered as domestic equipment unless you pay a lot of money) were infrared only, such as blu-ray / DVD and VHS players – unfortunately we still had to support VHS at the time. For our systems we had a total of 3 devices controlled by infrared as depicted below, however, in the past I have also seen a wide range of equipment on our campus controlled by infrared, some you might expect, others you would question why a one-way communication method like this had been used.

Over the years I’ve had quite a lot of experience with Extron equipment, and have done my fair share of ‘configuration’ (a term preferred by Extron for ‘programming’ their devices is in a lot of cases, the ‘programming’ is purely drag and drop). However I have had limited exposure to AMX and Crestron systems so was interested to see how the three aforementioned control systems manufacturers compared in terms of infrared provision.

Comparison of manufacturer IR support

Manufacturer Model IR TX ports RX method
Extron IPL 250 4 Built in receiver accessible via IP
Extron IPCP 505 8 Built in receiver accessible via IP
AMX NI-3100 & NI-4100 8 Additional hardware via RS-232
Crestron PRO2 & PRO3 8* Additional hardware via USB
* documentation suggests that additional (up to 3) card slots can be used each providing a further 8 IR outputs

In each case, the learning of infrared codes requires the use of a PC to build and store the infrared control driver. However it’s interesting to see that each manufacturer has chosen a different method of communication between PC and receiving device to achieve this. Each manufacturer has provided their own software for learning IR codes, all of which seem to be available for Microsoft Windows only.

Software required for IR learning

Manufacturer Software required Supported operating systems
Extron IR Learner Windows XP SP2 or later
AMX IREdit Windows XP SP1 or later
Crestron SIMPL/DEAL Windows XP SP2 or later

As a Linux user this is a bit disappointing. So why isn’t and why can’t software for control systems be written for a variety of platforms? Or better yet, written to be platform agnostic and available via the web – everything else seems to be going that way and this is the direction I’m hoping to take – perhaps there are very good reasons I haven’t considered that I’m yet to discover..

However one thing that I am hoping to achieve, as with all of the manufacturers listed above is to implement infrared control in a neat, ideally modular and potentially expandable way. The requirements of emitters I plan to use are that they will be low spill/low range wired with minimal components at the emitter end (preferably just a wire with an IR LED on the end) to position over the IR window of the device to be controlled. I have been investigating ways to achieve this and so far this is looking promising – I’ll publish further hardware information and a further comparison of products / software from Control4 / OpenRemote in due course, but my next post will cover some of the popular software options that are currently available for infrared transmission and learning.

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