A truely universal remote control for my EPIA system

November 9, 2009

Although it has been a bit quiet here lately, this does not mean that I have not made progress. As the first in a upcoming series of reports, let me talk a bit about the problem of finding a remote control for my EPIA system. You might wonder why I need a remote control, considering what I’ve explained so far what the EPIA is supposed to do. Meanwhile its purpose has expanded to become a digital TV system driven by VDR, with the help of a DVB-C card and some auxiliary hardware such as an infrared receiver (more on this later). Since such a system is not really meant to be controlled using a SSH connection or an attached keyboard, a remote control is a must. And since the whole system is a design of my own, I also need to choose a remote control model myself on the free market (try imagining the reaction of a ODM/OEM if you ask for the design of a single remote control).

Universal Remote Controls

Luckily the market offers a large variety of so-called universal remote controls, “universal” because they are supposed to replace almost any device-specific remote control by imitating its RC codes. Usually such a universal remote control is also designed to replace multiple remotes at once by allowing to be switched to different device types such as TV, SAT receiver, DVD player etc.

When it comes to select a universal remote control (URC) among the offerings, things get a bit difficult as soon as you make demands. In terms of basic functionality, they all work more or less the same, ie. it’s not as if a “Foo” device could be controlled by a “Bar” URC only. URCs can be roughly classified by distinguishing between models that employ code libraries only and models that can learn the codes from an existing remote control. The former have at first sight the disadvantage of having a fixed set of codes, meaning that if your device is not included in this set you might be out of luck. However, the code libraries used seem to be really huge and so far I have not found a single device that could not be controlled. The latter class might make it easier at first sight, however what do you do if your original remote control is no longer operational?

A second rough criteria to categorize could be the design and the price of the URC. While there are dozens of what I want to call simple models, being ordinary RCs with some means to enter codes or start learning, there are also complex models exhibiting a display or even a touchscreen. Well-known URC manufacturer OneForAll for example manufactures many simple models but also sells what I would call complex models in a higher price region. Logitech’s Harmony remotes also belong to the latter class. Personally I think these remotes are nothing but expensive gadgets: safe for the fact that, for instance, these Harmony remotes require a bloated PC software for any programming the cheaper simple models do their job just as good.

Note that functionality such as macros (sending multiple IR commands at once, eg. to turn on both TV and satellite receiver at once) and a PC interface does not depend on the price. You don’t have to buy an expensive, touchscreen-controlled remote to get PC connectivity — many OneForAll (and apparantly RadioShack) remotes, namely the ones manufactured by a company named UEI, feature a 6-pin connector in the battery compartment, the so-called JP1 interface, for which third-party hard- and software has been made available. This way even the internal code library could be extended for new devices.

The OneForAll URC-7525

To come to the point, I’ve chosen the OneForAll Digital 2 (URC-7525):

So why did I choose this particular model? This decision was in particular driven by the intended use as a remote for the VDR software. VDR supports remotes with a lot of different keys, as can be seen by looking at the example remote.conf included with the software:

  • Numeric keys (0-9), used eg. for direct channel selection
  • Channel selection keys (Ch+, Ch-, PrevChannel, Channellist)
  • Menu and Cursor keys (Menu, Ok, Back, Up, Down, Left, Right)
  • Color keys (Red, Green, Yellow, Blue)
  • Transport keys (Play, Pause, Stop, Record, FastFwd, FastRew, Next, Prev)
  • Audio stream/Volume keys (Audio, Vol+, Vol-, Mute)
  • EPG keys (Info, Schedule)
  • Other keys (Power, Timers, Recordings, Setup, Commands, User1-User4)

Note that these are just the different keys VDR can distinguish natively: you can freely map these to the keys your remote control actually offers and you don’t need to map all keys since most functions (eg. the Setup mode) can be accessed from within the Menu. The provision of a dedicated “Setup” key is just meant to provide a shortcut if your remote control possesses a suitably named button. However, some keys such as the color keys must be present.

Nevertheless it seems obvious that if one has the choice of using an arbitrary remote control, one wants to use a remote that exploits the available functions as good as possible. Thus I wanted no remote control that didn’t offer transport keys, for instance. And since transport keys and color keys exert different functionalities, these should not be mapped onto the same keys as with this Philips remote control, for instance. On the other hand, I don’t accept to wade through menus just to get information about the currently shown TV program. So the remote control should provide direct keys for such a feature, which rules out the OneForAll URC7950 remote control.

So that’s how I ended up with the URC-7525, officially called “Digital 2”. It has the special feature of being able to control TV and satellite/cable box at the same time without having to switch all the time: certain key codes always address the TV (such as Power, the Volume keys or the Videotext keys) while others always send to the satellite/cable box (in particular the channel selection keys). Of course, the decision to which device a key group sends can be modified.

Exploiting all remote control keys

Like all simple remote controls, the URC-7525 has to be set up for the particular device in use, such as your television model. Since LIRC, the software used on the EPIA to decode the IR signals, can decode almost anything, one is free to pick an arbitrary code for the cable/satellite device. In other words: there is, of course, no “VDR” in the code library, since there is no such thing as a single VDR device using certain IR codes. Instead you first program the remote to send a particular set of IR codes, preferrably of a device not already present at your home, and then have LIRC on the receiver side learn these codes.

Now the perhaps surprising challenge is to find a code where all keys on the remote work. If you enter the numeric code for a “Condor” satellite receiver into the URC, for example, the “?”, “PPV” and “Subt.” buttons will remain dead since there is apparantly no satellite receiver function that could be mapped to these buttons in a meaningful manner. Thus, you can spend a lot of time entering a large number of codes trying to find one where all keys work…

It would have been easier if OneForAll had documented such a code, but well, to save you the time: from experimenting I’ve found code 21957 to activate nearly all keys in the bottom section of the remoteĀ  (the only key I found to stay dead is the “-/–” dead left of the 0 key). This code apparantly belongs to Dilog sat receivers and generates RC5 signals. So just enter this code into your remote and enjoy!

(For the record: my Tevion TV requires code 10714.)

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Posted in EPIA MII by Pieter Hollants

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