Question about Tellstick Raw RF Broadcast Format

[johnnysix]

I'm writing a C# utility that translates a Philips Pronto code for a Home Easy HE105 Heating Controller into a RAW format to send from the Telldus 'tdtool' command line (may be fruitless, I know...). I understand the format of the Pronto, and the burst-length encoding within Telldus RAW format ("S$kk$kk$$k$..." etc), but I don't understand why each Tellstick data bit has to be encoded with four transitions. (i.e.1->0->1->0). At least that is what is described the NEXA example given by Telldus.

I thought all IR codes where Manchester Encoded, which requires only ONE mid-clock transition per data bit, i.e.

Data '1' = 1,0
Data '0' = 0,1

Can anyone tell me where I'm going wrong in my interpretation? If I can figure this out then I might be able to post my program for others to use.

[johnnysix]

OK... at the risk of talking to myself...

It seems the four-state data bits are a feature of the NEXA RF format. However it was my belief that most of these units used the same ArcTech protocol, and only two-state data bits would be required.

Next stage then is to see if I can emulate the exact burst/space gaps that the ProntoPro Tx Code infers. I'm still a little unsure about lead-in and lead-out periods required.

This is turning into a blog, isn't it ...?

[johnnysix]

Unfortunately I tried LOTS of different RAW command encodings without success. At this point I'm not certain that the Telldus RAW command can generate the lengthy lead-in and lead-out bursts required for the HE105. I don't know if they are framing my commands with extra unseen bursts.

I wish Telldus would say more about their raw transmissions! I get the impression they might only work with ARC formats.

[micke.prag]

It is a correct observation that the four bits are for the ArcTech protocol.

I don't quite understand what you have problems with. Do you have any output from an oscilloscope to compare with?

[johnnysix]

My query is whether Telldus device drivers actually *ADDS* any extra RF burst framing to the bursts defined within the ASCII character sequence in the RAW string.

e.g. Does it automatically broadcast an ultra-long ON/OFF lead-in signal (to allow the receiver AGC to adjust) followed by the ON/OFF bursts defined in the Telldus command string. It could do so if you assume some sort of standard AGC behaviour of receiving equipment.

My hope would be that the ONLY RF activity broadcast by the Tellstick would be what is defined in the RAW string, from beginning to end. However, this would mean the Raw Command can only simulate a maximum burst of 1.270 milliseconds (ASCI '127' * 10us), where some devices require up to 8ms ON and 4ms OFF as a lead-in !

I hope that is clearer. Thanks for the attention.

[micke.prag]

My query is whether Telldus device drivers actually *ADDS* any extra RF burst framing to the bursts defined within the ASCII character sequence in the RAW string.

It should not. If it does it is a bug.

e.g. Does it automatically broadcast an ultra-long ON/OFF lead-in signal (to allow the receiver AGC to adjust) followed by the ON/OFF bursts defined in the Telldus command string. It could do so if you assume some sort of standard AGC behaviour of receiving equipment.

No, you will have to define this yourself in the raw-string. We do this for some protocols already.
Check for instance:
http://developer.telldus.com/browser/te ... lHasta.cpp
http://developer.telldus.com/browser/te ... anChip.cpp

The 10 us pulse (ASCII '1') is a special pulse in batch 9 and later. It combines to pulses making it possible to send longer than 255*10.

My hope would be that the ONLY RF activity broadcast by the Tellstick would be what is defined in the RAW string, from beginning to end. However, this would mean the Raw Command can only simulate a maximum burst of 1.270 milliseconds (ASCI '127' * 10us), where some devices require up to 8ms ON and 4ms OFF as a lead-in !

Please see above. The character array is treated as unsigned internally making 255 the longest single (non combined) pulses.

[johnnysix]

What do you mean by 'Batch 9' ... and how do I know what I've got ?

I plan to pursue this further this weekend.

[micke.prag]

The batch is written on the label on the product.