source= http://www.piclist.com/piclist/2003/11/26/072840a.txt? olin_piclist says: > Argh! Look James, I know you don't like my "grumping" about > wanting a spec, but that lack of exact spec is the big > problem here and probably the reason you aren't getting > useful answers. > Ok, I'll try again: How about... A circuit with two inputs and one output. All I/O optical in the human visible light range. All I/O in pulses of light of a width and frequency range discernable by the human eye. (0 to 20 Hz) The output frequency varies over the range in inverse proportion to the mathematical product of the input frequencies with an acceptable error of 10 percent. Optimize the design for low cost of production by assembly workers who have little technical ability. olin_piclist says: > I would use a 12F629 running on its internal 4MHz oscillator. > These things are well under a buck in quantity and you > wouldn't need a crystal or resonator. > Ok, that is a point... I may be wrong about the analog design being better. Using a PIC would also allow other information to be transmitted (in a later design revision, Olin, I'm not changing the spec for this one! ) such as power levels, layout of the blocks before this one, etc... --- James Newton: PICList.com webmaster, former Admin #3 mailto:jamesnewton@piclist.com 1-619-652-0593 phone http://www.piclist.com/member/JMN-EFP-786 PIC/PICList FAQ: http://www.piclist.com -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body