IR Relay Function

[Nad]

Hi all,

I was wondering if anyone can offer some guidance on how to get the IR relay function working? I want to control my sky box from my bedroom. I have DFPs in both locations so i want to relay any IR packets received in the bedroom to the DFPs IR transmitter in the room where the Sky box is. I can see where you select the relay option but i can't see how you tell the system where to relay the frames to.

Thanks,
Nad

[Karam]

The relay function will cause the RX module to broadcast the IR data to all IR TX capable modules (the data packets are targetted at IR TX TYPE group). You may wish to choose relaying of unrecognised frames only if your RX is also being used for Idratek system control functions. IR TX modules however have a gating on whether they actually emit relayed IR data. I believe the default setting in Cortex is 'disabled'. This gate can be found in any virtual handset connect to an IR TX object and is called 'Accept relayed frames'. Note that the setting affects the parent IR TX object as a whole, i.e if you have multiple handsets connected the object then ticking this box in ANY handset will mean it is enabled for that IR TX device.

It is in principle possible to target relayed packets to a specific module address but this requires delving into reflex and I'm guessing probably not required for this application.

However, you have mentioned 'sky box' and I'm already expecting some problems as there appears to be some issue with the IR protocol used by the sky box remotes which we were investigating with someone else. Nonetheless I'd be interested to hear your experience and if you do have problems please follow up with e-mail letting us know the details of the make/model number of the skybox and the remote handset.

[achapman]

That's interesting. I was looking to do something related. ATM the volume controls on my Sky remote have no function as my Sky sound goes through a Sonos system. I had hoped to intercept the Volume up, volume down and mute signals from my sky remote with an ITR-002 then have them fire a macro with a shell command. The shell command would generate the UPNP messages to get Sonos to increase/decrease or mute the volume.

So I'd be interested in some feedback on whether this is practical.

thanks,
Andrew

[Nad]

Hi Karam,

Apologies for not getting back to you on this, I've been away for a while and didn't have access to Cortex, back on the case now though

I just updated to the latest version of Cortex and the IR relay function seems to work fine now. I didn't make any changes to Cortex besides the update, did you guys implement a fix? I think i was on version 25.0.14 and now 25.1.4.

Either way, I had a quick test it seems to work exactly as required, i'll do a bit more testing tomorrow to see if all the buttons on the remote are working.

Thanks,
Nad

[Nad]

OK, done a bit more testing it doesn't work quite as well as i would like. It works some times and then not at all at other times, very odd

Looks like the relay function doesn't work too well at all but i have complete and total control via Cortex and using the Cortex copy of the Sky remote.

[cliffwright]

OK, done a bit more testing it doesn't work quite as well as i would like. It works some times and then not at all at other times, very odd

Looks like the relay function doesn't work too well at all but i have complete and total control via Cortex and using the Cortex copy of the Sky remote.

'How' does Idratek / Cortex pass each IR command through? Does Cortex have to 'learn' each expected IR command in order to replay it or does it literally pass through the exact IR code that has been received without having learnt this prior?

I'm going to be needing something similar soon too to control some AV equipment remotely . . .

[Karam]

Cortex does not have to learn IR data and then replay it to the transmitter, data goes straight from one module to the other. But Cortex can control the mode of operation. What you need to understand is that the IR RX module first decodes the IR frame then it checks to see if this matches any patterns it has been taught. If so then it marks it as a recognised frame and potentially could perform user defined Reflex actions assigned to that learnt frame. Or it could just send a message to Cortex saying 'I've just received recognised frame N' without sending the actual data. Or it could broadcast (relay) the data to the network targetting IR TX modules. Or it could do a mixture i.e if recognised frame then only send message to Cortex but if unrecognised just relay data to IR TX modules. The latter option allows you to train some buttons on a handset for system controls whilst allowing others to just pass through.

Since each IR module can only be trained to recognise 16 frames (for system control purposes) Cortex can go beyond these (extended frames) by learning to recognise frames itself, but the disadvantage is the module has to send the entire IR data to Cortex rather than just one short packet.

In addition to all of these receiver side functions an IR transmitter module can be trained (for storage only - not recognition) about 140 different IR frames which it can then later be asked to regurgitate. So for example you can teach it the various buttons on a TV handset and then if you want to operate the TV from Cortex or indeed via Reflex from another module it is just a matter of sending a message to the module asking it to emit frame N.

These capabilities are useful but the downside is that because it is not just 'dumb' relaying of IR data the module has to somehow try to encapsulate into a packetised format the wide range of different IR formats that exist. Most common ones are catered for but formats that diverge widely from the norm may not work. There is also specific decoding of RC5 format which allows a more concise packet to be generated. However it may be that this gets in the way when the code format is RC6 in which case RC5 decoding can be switched off.

In a nutshell then, in many cases the standard controls shown in Cortex should enable you to perform relayed IR control of your equipment ok as well as to control it directly via Cortex e.g for automated functions. However there may well be some problems if the equipment uses a problem format. At the moment there is known to be an issue with some sky box controllers (not all are the same..) though it's status is 'unresolved' rather than 'can't be done'.

[Karam]

OK, done a bit more testing it doesn't work quite as well as i would like. It works some times and then not at all at other times, very odd

Looks like the relay function doesn't work too well at all but i have complete and total control via Cortex and using the Cortex copy of the Sky remote.

When you get a moment e-mail me and we can try to analyse what you have so far and try one or two things.

[Kevin]

Interested to see how you progress with this as I'm currently doing some xAP enabling work on an Ethernet based IR RX/TX system and so I am getting quite involved in the specifics of IR encoding as well as how to represent a learned code uniquely, in a way it can be reproduced algorithmically.

RC5 is reasonably straightforward but has a toggle bit that requires inverting for each press of a (same) key , some receivers insist on this but some also implement an interframe timeout that allows it to be ignored . I don't know if IDRANet IR devices handle this transparently when an RC5 code is learned? It can sometimes explain the works 'most times' experience. If they don't there is a workaround that I can go into if needed.

RC6 itself is not publicly documented and is quite a pain. It also uses Manchester / bi-phase encoding but has a non standard double period mark and space period right in the centre of the data which typically breaks standard bi-phase decoders as the expected edge transition is absent. These double width periods are also inverted as the toggle bits for consecutive keypresses.

Sky's RC6 is actually RC6-6-20 which just means the 'mode' is 6 and the data carries 20 bits. There are longer RC6 codes too (32 bit) but I don't think these are used by Sky. I don't have Sky+HD so I haven't tried that.

K