Re: mode2 reports noise values

On Thu, Feb 09, 2006 at 01:58:37PM -0800, Russ Weeks wrote:
> Hi, all.
> 
> I have just build a homebrew receiver following the instructions and
> schematics at lirc.org, and I've build and installed lirc from CVS.  My
> electronics supplier couldn't provide the TSOP17 IR receiver, so I
> substituted with the PNA4602M.
> 
> When I run mode2 without pressing any buttons, it rapidly prints
> alternating pulses and spaces.  The values appear to be a random
> distribution between 0 and about 2500.
> 
> When I run mode2 and press a button on my remote control, intermittent
> values jump to nearly 40,000.  I graphed the values here:
> http://linuxmedianetwork.blogspot.com/2006/02/lirc-help.html

The receivers can be sensitive to noise(electic and light).
Try turning off any lights to see if that has any effect.

Using a volt meter check the output of the 5v regulator.

Double check your pinouts on the receiver(they vary from one manufacturer
to the next),  and check the regulator pinout(it differs for small
78L05 versus large 7805).

Try adding a small cap(0.01 <--> 0.1uf) between the receiver ground
and 5v pins.

> My understanding is that mode2 should not print any values until a
> button is pressed.  Will this make it impossible to record my remote
> control commands?

Yes, mode2 should stay quite(not show pulses or spaces) when no
remote is used.

>  Is there some way to tell lirc to disregard any
> values below a certain threshold?  I have tried insmod'ing the kernel
> module with sense=0 and sense=1, no effect on the result.

No, it's a digital signal(on/off) at the input to the computer.

> 
> Thanks,
> 
> Russ
> 



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