SIRC Question

[UTMonkey]

Hi All,

I have written some code which generates an SIRC signal which tells my TV to mute (much to my wife's annoyance).

Thing is; for it to work I send the signal, wait 45ms (Thanks to Nigel's tutorials), and then send the signal again for it to work.

Is this usual for Sony devices?

Mark

 

[Gayan Soyza]

I'm not sure what you need.But you have done that.

SIRC for Sony devices.Just change the Device ID so you can use with Sony VCR/DVD etc.....

 

[Pommie]

It could be the automatic level control that takes time to adjust. What happens if you send a different command followed by the mute command?

Mike.

 

[Nigel Goodwin]

Hi All,

I have written some code which generates an SIRC signal which tells my TV to mute (much to my wife's annoyance).

Thing is; for it to work I send the signal, wait 45ms (Thanks to Nigel's tutorials), and then send the signal again for it to work.

Is this usual for Sony devices?

Quite possibly so, as SIRC's sends continually while the button is held done it's rather difficult to know - my SIRC transmitter does the same - why only send it once when the original doesn't?.

As Pommie suggests, it may be the time taken for the AGC to settle down, bear in mind there is no preamble sent - so the first set of pulses may be used as preamble?.

 

[geko]

Thing is; for it to work I send the signal, wait 45ms (Thanks to Nigel's tutorials), and then send the signal again for it to work.

Is this usual for Sony devices?

I was recently playing around with Sony SIRC myself and what I found is that all my Sony remotes send the IR command a minimum of 3 times regardless of how quickly I press the button on the remote. If you hold a button down it repeats for as long as it's held down, but always a minimum of 3 times.

http://picprojects.org.uk/projects/sirc/

 

[Gayan Soyza]

But I have an ancient sony TV remote RM 626 model its bit different format supported.not 12,15,20 bits.............

 

[UTMonkey]

Sorry for not getting in touch sooner, I don't get much chance to do electronics.

It could be the automatic level control that takes time to adjust. What happens if you send a different command followed by the mute command?

That's a good question, let me try (some time passes......)

Ok, here are the results, if I send the mute once and then channel+ nothing happens.

If I send the Channel+ twice my TV responds.

So I think that answers my question, Sony kit likes to see a code more than once within a particular time frame (probably 45ms but I won't bother checking).

Thanks to all for your help.

Mark

 

[Nigel Goodwin]

Geko suggested that it's always sent a minimum of three times, so if you're not doing it from a button like a remote control, then perhaps you should send it three times?.

 

[philba]

Most remote controls send the command packet 3 times. I've always heard that it's to increase reliability. The receiver compares the packets and if they aren't the same it throws them away. I don't know if they do 2 out of 3 or what.