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Control a servo from a potentiometer, WITHOUT a microcontroller?
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T3sl4co1l:
No need for an oscillating solution.  A couple transistors and their supporting resistors (and maybe an R+C or two for compensation) will do it.  Mechanical setup, probably a pot on the servo shaft to indicate position, and the error amp controls the servo to match input voltage to position.

Tim
m98:

--- Quote from: SiliconWizard on December 04, 2019, 05:27:08 pm ---
--- Quote from: m98 on December 04, 2019, 04:23:55 pm ---Another solution: One GreenPAK

--- End quote ---
Nice devices. But they are "programmable", aren't they? So requiring some "lines" of "code". Or I don't know exactly how you configure them.

--- End quote ---
They have a schematic entry tool, so no "lines of code" required. In fact, as far as I know, that's the only official way to configure them.
But this boils down to the question if programmable hardware is permitted by the rules the OP had in mind, really.
One could even make the case that a PCB created by a CAD-tool contains "code", since it is stored in markup language and "programmed" in the manufacturing process.
m98:

--- Quote from: T3sl4co1l on December 04, 2019, 06:06:47 pm ---No need for an oscillating solution.

--- End quote ---
There is, unless re-specifying the used servo was allowed. In that case, he could simply use one that takes analog input off-the-shelf...
Benta:

--- Quote from: T3sl4co1l on December 04, 2019, 06:06:47 pm ---No need for an oscillating solution.  A couple transistors and their supporting resistors (and maybe an R+C or two for compensation) will do it. 

--- End quote ---

My reading of the OP is that he's talking about RC servos.

These need a 0...4.8 V input amplitude, 20 ms period, 1...2 ms pulse input; 1.5 ms being neutral position. I don't see a solution without an oscillator.

I wanted a rude username:
What have I started?  :o

It's best if the set of rules emerges organically. If you want clarification, then personally I would make the number of components/lines of code follow the complexity of the solution in some way.

Programmable devices like FPGAs and PLCs may need to count as having some number of "function points", even if they're programmed via a 4GL, Node-RED style Web interface, etc. ... otherwise of course you could build pretty much any solution in an FPGA and hope the decoupling caps don't push you over someone else's solution.

Existing libraries are OK, because they're just other building block. But the library should exist publicly when the challenge is put forward ... no MyLibrary.solveTheProblem().  ;D

Anyway, those are just suggested rules. And yes, I was thinking of a generic, unmodified PWM servo, but it's also fun to consider hacking it.
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