Post by thread:PIC & iButton

Hi. I was looking into the single-wire iButtons, and wanted to hook up aprox 100 "reader-stations" spread out over 50,000 square feet, which all funnel down to a single PC via serial port. (Or perhaps a couple serial ports if need be) What I envision is having several pics, each having the capability to provide contacts to read 5-10 iButtons.. Each of these pics would reside on some common bus and eventually stream the data to a PC with a serial port. Each contact station would append a "station-id" to the 64bit serial number that the iButton reports... Has anyone been exposed to a setup like this? Leslie Bester Chief Technical Officer Gallmark Corporation 500-280 Smith St. Winnipeg, MB. R3C 1K2 Contact Specifications: 204-944-1119 (voice office) 204-949-0768 (fax office) 204-933-5164 (pager) 204-229-1082 (cellular) spam_OUTlesTakeThisOuTgallmark.mb.ca (email) .....pagerKILLspam@spam@gallmark.mb.ca (email pager) -----BEGIN GEEK CODE BLOCK----- Version: 3.1 dpu(--) s: a- C+++(++++) UL++(++++) P++(+++>) L+++(++++>) E- w++ O M- V PS+ PE Y-- PGP- t@ 5@ X+(++) R(-) tv- b+(++) DI+++ D+ G e h(*) r y+ z ------END GEEK CODE BLOCK------

Hi, please clarify. In fact, the main question is, whether you want that amount of said iButtons (5-10 pcs) exactly at once, or rather you want only to set up reader stations. That is, iButton reader stations can be connected to ONE one-wire bus provided there is no collision, i. e. only one iButton is connected at one time. With other words: one one-wire bus can serve a vaste amount of reader stations IF there is only one button. Further: Dallas provides a sophisticated mechanism called Search ROM which makes possible to connect more Buttons at a time to a particular bus. And this only one pin of a PIC! The allowed length of the bus I do not know off the cut, but this can be the major factor to calculate the number of PICS, which, on the other hand, can be connected together to a RS-485 bus. I hope this helps. Regards, Imre On Thu, 21 Oct 1999, Les wrote: {Quote hidden}> Hi. > I was looking into the single-wire iButtons, and wanted to hook up aprox 100 > "reader-stations" spread out over 50,000 square feet, which all funnel down > to a single PC via serial port. (Or perhaps a couple serial ports if need > be) > > What I envision is having several pics, each having the capability to > provide contacts to read 5-10 iButtons.. Each of these pics would reside on > some common bus and eventually stream the data to a PC with a serial port. > Each contact station would append a "station-id" to the 64bit serial number > that the iButton reports... > > Has anyone been exposed to a setup like this? > > > Leslie Bester > Chief Technical Officer > Gallmark Corporation > 500-280 Smith St. > Winnipeg, MB. R3C 1K2 > > Contact Specifications: > 204-944-1119 (voice office) > 204-949-0768 (fax office) > 204-933-5164 (pager) > 204-229-1082 (cellular) > lesKILLspamgallmark.mb.ca (email) > .....pagerKILLspam.....gallmark.mb.ca (email pager) > > -----BEGIN GEEK CODE BLOCK----- Version: 3.1 > dpu(--) s: a- C+++(++++) UL++(++++) P++(+++>) > L+++(++++>) E- w++ O M- V PS+ PE Y-- PGP- t@ 5@ > X+(++) R(-) tv- b+(++) DI+++ D+ G e h(*) r y+ z > ------END GEEK CODE BLOCK------ > >