Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755138AbYJHMEk (ORCPT ); Wed, 8 Oct 2008 08:04:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754580AbYJHMEc (ORCPT ); Wed, 8 Oct 2008 08:04:32 -0400 Received: from mail-in-02.arcor-online.net ([151.189.21.42]:50937 "EHLO mail-in-02.arcor-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751299AbYJHMEb (ORCPT ); Wed, 8 Oct 2008 08:04:31 -0400 From: Bodo Eggert <7eggert@gmx.de> Subject: Re: Toggling GPIO at 38Khz To: Jon Smirl , ARM Linux Mailing List , lkml Reply-To: 7eggert@gmx.de Date: Wed, 08 Oct 2008 14:15:19 +0200 References: User-Agent: KNode/0.10.4 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit Message-Id: X-be10.7eggert.dyndns.org-MailScanner-Information: See www.mailscanner.info for information X-be10.7eggert.dyndns.org-MailScanner: Found to be clean X-be10.7eggert.dyndns.org-MailScanner-From: 7eggert@gmx.de Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 925 Lines: 15 Jon Smirl wrote: > I'm working on getring the LIRC IR subsystem integrated into the > kernel. One common IR hardware implementation is based on standard > serial ports. It uses the serial port's DCD and DTR as GPIO pins. > This common IR hardware does not have a transmit modulator and is > modulating the IR signal in software. Luckily is has hardware > demodulation. > > There are four common IR frequencies - 36Khz, 38Khz, 40Khz, 56Khz. I > need to create these frequencies in software. Data is then transmitted > as 400-600us burst of these frequencies. Around 10-30 clock pulses. [...] The ALSA PC-Speaker sound driver might do something similar ... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/