From mboxrd@z Thu Jan 1 00:00:00 1970 From: lirc@bartelmus.de (Christoph Bartelmus) Subject: Re: [PATCH 13/13] IR: Port ene driver to new IR subsystem and enable it. Date: 31 Jul 2010 19:47:00 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from moutng.kundenserver.de ([212.227.17.8]:55676 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751320Ab0GaRt7 convert rfc822-to-8bit (ORCPT ); Sat, 31 Jul 2010 13:49:59 -0400 In-Reply-To: Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: jonsmirl@gmail.com Cc: awalls@md.metrocast.net, jarod@wilsonet.com, linux-input@vger.kernel.org, linux-media@vger.kernel.org, lirc-list@lists.sourceforge.net, maximlevitsky@gmail.com, mchehab@redhat.com Hi Jon, on 31 Jul 10 at 12:25, Jon Smirl wrote: > On Sat, Jul 31, 2010 at 11:12 AM, Andy Walls > wrote: >> I think you won't be able to fix the problem conclusively either way= =2E =A0A >> lot of how the chip's clocks should be programmed depends on how the >> GPIOs are used and what crystal is used. >> >> I suspect many designers will use some reference design layout from = ENE, >> but it won't be good in every case. =A0The wire-up of the ENE of var= ious >> motherboards is likely something you'll have to live with as unknown= s. >> >> This is a case where looser tolerances in the in kernel decoders cou= ld >> reduce this driver's complexity and/or get rid of arbitrary fudge >> factors in the driver. > The tolerances are as loose as they can be. The NEC protocol uses > pulses that are 4% longer than JVC. The decoders allow errors up to 2= % > (50% of 4%). The crystals used in electronics are accurate to > 0.0001%+. But the standard IR receivers are far from being accurate enough to all= ow tolerance windows of only 2%. I'm surprised that this works for you. LIRC uses a standard tolerance o= f 30% / 100 us and even this is not enough sometimes. =46or the NEC protocol one signal consists of 22 individual pulses at 3= 8kHz. If the receiver just misses one pulse, you already have an error of 1/2= 2 > 4%. Christoph -- To unsubscribe from this list: send the line "unsubscribe linux-input" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html