From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 28 Aug 2001 16:55:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 28 Aug 2001 16:55:01 -0400 Received: from mail.lightning.ch ([193.247.134.3]:54021 "HELO mail.lightning.ch") by vger.kernel.org with SMTP id ; Tue, 28 Aug 2001 16:54:52 -0400 Message-ID: <3B8C0475.6050103@lightning.ch> Date: Tue, 28 Aug 2001 22:52:05 +0200 From: Jean-Christian de Rivaz User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.3) Gecko/20010801 X-Accept-Language: en-us MIME-Version: 1.0 To: Tony Hoyle Cc: linux-kernel@vger.kernel.org Subject: Re: Treating parallel port as serial device In-Reply-To: <9mgtpb$mf4$1@sisko.my.home> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Take a look to the MAX3100 chip: http://pdfserv.maxim-ic.com/arpdf/MAX3100.pdf This solution highly reduce the CPU overhead needed to sample Rx line for each single bit. The chip have a FIFO, an interrupt and look like a standard UART. Only the bus transfert with the CPU is different. I curently work on a driver for it. Regards, Tony Hoyle wrote: > I'm looking to attach a serial device to my box that has only TTL level > I/O. Since I'm more of a software than a hardware person making a > circuit board up with a max232 in is a bit risky... I want to connect > the I/O to the parallel port. > > What I need now is a driver that can read the input from a pin on the > parallel port and treat it as serial input. It sounds like the kind of > project that would have been done before, but I can't find anything that > even comes close. Userspace probably wouldn't cut it as I'm reading as > 9600 baud and usleep doesn't have nearly enough resolution. > > Tony > >