From owner-freebsd-hackers Wed Jun 3 17:19:51 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id RAA10327 for freebsd-hackers-outgoing; Wed, 3 Jun 1998 17:19:51 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from oznet11.ozemail.com.au (oznet11.ozemail.com.au [203.2.192.118]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id RAA10194 for ; Wed, 3 Jun 1998 17:19:29 -0700 (PDT) (envelope-from joe.shevland@horizonti.com) Received: from horizonti.com ([203.33.128.245]) by oznet11.ozemail.com.au (8.8.4/8.6.12) with ESMTP id KAA21940; Thu, 4 Jun 1998 10:19:10 +1000 (EST) Message-ID: <3575E7C2.A77935C4@horizonti.com> Date: Thu, 04 Jun 1998 10:18:10 +1000 From: Joe X-Mailer: Mozilla 4.04 [en] (WinNT; I) MIME-Version: 1.0 To: Mike Smith , hackers@FreeBSD.ORG Subject: Re: UART's References: <199806032302.QAA01885@dingo.cdrom.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Mike Smith wrote: > > > I wasn't sure if this was a newbie question to be directed at hackers or > > vice-versa, so here it is. > > > > I'm interested in writing a device driver for a 16550 UART serial port > > (I hope that's right). Is there a few good source code files to gain an > > understanding of this in the kernel source? > > Is this meant to be a driver for FreeBSD, or some other operating > system? If the former, what's wrong with the driver we already have? :) Nothing's wrong with it at all. Sorry, I should have expanded. The driver is going to be for Windoze, because their standard serial driver cannot cope with a particular problem I'm experiencing. A friend has set up a fish-feeding device (sits on a mast out in a lake) that provides feedback and other services, communicating with a PC back 'on-shore'. Using an RS232 serial connection between the two devices (PC - custom device) is fine, as is a current loop. However, when a radio signal is used (with a much higher packet error rate), the Win driver vomits and replies that it has 0 bytes in the read buffer (even though the other device is happily transmitting). The interesting thing is that slower (CPU) PC's work better than faster PC's when using the radio transmission. That's pretty sketchy (and prob. doesn't make sense), but that's all I know as of this minute. Anyway, just wanted to see how FBSD handles the UART. Cheers. > -- > \\ Sometimes you're ahead, \\ Mike Smith > \\ sometimes you're behind. \\ mike@smith.net.au > \\ The race is long, and in the \\ msmith@freebsd.org > \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message