http://www.circuitcellar.com/library/toc.asp ISSUE 113 December 1999=20 Theme: EMBEDDED INTERFACING The Poisson Network=97A One-Way Architecture for Data-Collec-tion Applicati= ons , by Carl Huben, 12. I like reading old issues of Circuit Cellar just as much as the new ones. The article above is for a wireless network with many transmit-only sensors= running on batteries. -----Original Message----- From: Dave King Sent: May 24, 2004 5:30 PM To: PICLIST@MITVMA.MIT.EDU Subject: [PIC]: Extended Sensor Net & Pic I wasn't quite sure this was the correct topic tag. I'm working on a project that involves a large sensor array spread over a couple acres. I think the longest run so far is about 2500 meters (~8000 feet) with a sensor every 75 meters (~200 foot). All the sensors are monitored by a master PC. So the cables have to be waterproof etc and neither cause or be affected by RF. Right now the big problem seems to be the layout without resorting to Cat-F. Probably need a few hubs buried out there to make it work. Any good reference stuff to look at this type of extended net setup? I've been looking at building the interface using either a RTL8019AS or CS8900-IQ. Are there any others I should look at? The actual sensors are pretty simple and a 12C509A was selected and easily more than handles (on the bench) what it has to do. I think the 509's will have to be replaced with something with a bit more power and pins such as a 870/877 before it would handle both its sensors and the ethernet overhead. Are there any better suited pics? Dave -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body