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#1 Bill Harris

Bill Harris

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Posted 28 October 2004 - 06:58 AM

This is WAY offtopic so I figure that floobydust is the proper place for this.

During earlier incarnations in the '80's and '90's I was heavily into astrophotography. I built my own telescope and associated electronics.

One of the electronical doodads was electronic digital position indicators called _digital setting circles_. Analog "Setting circles" are large degree wheels which are finely divided and a PITA to read in the dark. The elcctronic version is easier to read and use.

My setup from 1989 consisted of a Hewlet-Packard optical encoder to determine the position of the axis, with the signal going to an up-down counter (Harris/Intersil) which drove a 0.3" LED display. Worked tolerably well, except the up-down counter is unexplicably glich-prone. On four 3x5" stacked and interconnected PCBs with dozens of SMT components, all hand made. I was a nut for detail...

Two axes (axixes?), one reading 0 to +90 to 0 to -90 to 0 in degrees to 0.1 degree and the other reading like clock-like (hours and minutes) 0h0m to 23h59.9m to 0.1 minute.

I plan to resurrect the scope and want de-so my digital setting circles. Would the counters be do-able with PIC technology? If so, I'll start kicking around ideas for an upgrade.

--Bill