---- START NEW MESSAGE --- Received: from cherry.ease.lsoft.com [209.119.0.109] by dpmail10.doteasy.com with ESMTP (SMTPD32-8.05) id A2004340182; Fri, 30 Jan 2004 08:10:40 -0800 Received: from PEAR.EASE.LSOFT.COM (209.119.0.19) by cherry.ease.lsoft.com (LSMTP for Digital Unix v1.1b) with SMTP id <21.00CC4E3D@cherry.ease.lsoft.com>; Fri, 30 Jan 2004 10:40:20 -0500 Received: from MITVMA.MIT.EDU by MITVMA.MIT.EDU (LISTSERV-TCP/IP release 1.8e) with spool id 0275 for PICLIST@MITVMA.MIT.EDU; Fri, 30 Jan 2004 10:40:14 -0500 Received: from MITVMA (NJE origin SMTP@MITVMA) by MITVMA.MIT.EDU (LMail V1.2d/1.8d) with BSMTP id 1586; Fri, 30 Jan 2004 10:38:39 -0500 Received: from embedinc.com [68.162.221.141] by mitvma.mit.edu (IBM VM SMTP Level 430) via TCP with ESMTP ; Fri, 30 Jan 2004 10:38:38 EST X-Comment: mitvma.mit.edu: Mail was sent by embedinc.com Received: from 192.168.0.3 (main) by mail.embedinc.com ; 2004 JAN 30 10:39:20 EST References: <200401301456.i0UEuOK13845@sprucegrove.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: <002901c3e747$1a79a5a0$0300a8c0@main> Date: Fri, 30 Jan 2004 10:38:25 -0500 Reply-To: pic microcontroller discussion list Sender: pic microcontroller discussion list From: Olin Lathrop Subject: Re: [EE]: Challenge for keen minds To: PICLIST@MITVMA.MIT.EDU Precedence: list X-RCPT-TO: Status: U X-UIDL: 371856515 D. Jay Newman wrote: > How about something that watches the gate through a telescope from > *inside* the protected area. It could bounce an I/R laser off of a > reflector. If the signal is lost then a secondary system would check > if the gate is open. > > Of course, this works in perfect weather. > > What *are* you protecting? A warehouse full of high tech gate sensors? ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body .