Post by thread:PICLIST Digest - 21 Jan 1998 to 22 Jan 1998

>I'm writing a C compiler fo microchip 16C84. The output is a full commented >MPLAB assembler file. I just made the parser and a part of compiler. >Give a look at this code (c -> asm) and tell me what do you think. >(This is a very stupid program). I am very much interested in a free C compiler. I would be nice to post the source on www. Regards, Michel

> I am currently working on a network of PIC controlled units for > minitoring machines in a manufacturing plant. The units will connect to > a 485 bus and will be interogated by a PC (master/slave setup). I am a > bit unsure about the practical aspects of such a bus in an industrial > environment since this is my first attempt at it. I would appreciate any > comments from people who have done this before: > > I was thinking on routing the bus through each slave unit. You would > have a female plug going in and a male plug going out. If the unit needs > to be removed, then the two parts of the bus can simply be plugged into > each other. The alternative is to use T-style taps from the bus, but > I am not sure how to make the T connections easily and reliably. Also, > is DB9 plugs/sockets acceptable in the industrial environment? > We use a 485 bus(57600 baud) on our plastic molding machine monitoring equipment. The differental operation of 485 helps its noise immunity plus we run it in sheilded cable. Remeber the terminator. We use a terminal system that lets the units be wired in or out of the bus (usually the term board does not have to be removed for service).

> How much would a RADAR cost to cover the area? How easy is it to detect a person > on RADAR? They door opener detectors at stores and some alarm systems use microwave units for detecting movement. Not really RADAR as they only detect the doppler shift caused by movement and not the range.