From owner-freebsd-hardware Sat May 16 08:09:42 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id IAA23824 for freebsd-hardware-outgoing; Sat, 16 May 1998 08:09:42 -0700 (PDT) (envelope-from owner-freebsd-hardware@FreeBSD.ORG) Received: from sasami.jurai.net (winter@sasami.jurai.net [207.153.65.3]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id IAA23817 for ; Sat, 16 May 1998 08:09:38 -0700 (PDT) (envelope-from winter@jurai.net) Received: from localhost (winter@localhost) by sasami.jurai.net (8.8.8/8.8.7) with SMTP id LAA10757; Sat, 16 May 1998 11:09:38 -0400 (EDT) Date: Sat, 16 May 1998 11:09:38 -0400 (EDT) From: "Matthew N. Dodd" To: Duncan Barclay cc: freebsd-hardware@FreeBSD.ORG Subject: RE: interesting stuff In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Sat, 16 May 1998, Duncan Barclay wrote: > It's usually easier to do these on the parallel port (god knows how many > phase locked loops I've programmed down that!). Agreed. Hacking the parallel port gets quick and dirty results. > One "problem" with the I2C is that it is not a TTL compatible bus, so a > bit of hardware is need to convert the logic levels. > > Secondly, the framing on the I2C bus doesn't lend itself well to UART > style parity/start/stop bits. One problem with the parallel port is that it won't be sufficient for remote sites that want temperature monitoring hardware hanging off a serial port. I think any less than simple design (I can get a $99 I2C to RS-232 dongle from a number of different places.) implies multiple I2C busses, a small PIC or processor and other stuff. I'm actually talking with the guys that make the HLT about doing this project. > I would suggest that a parallel port driver be plugged into the ppbus > framework. It owuld be something I would find useful at work! Heh. Great for hacking value but remote terminal servers only speak LPD over their parallel ports (if they even have any). /* Matthew N. Dodd | A memory retaining a love you had for life winter@jurai.net | As cruel as it seems nothing ever seems to http://www.jurai.net/~winter | go right - FLA M 3.1:53 */ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message