The beginning Idea:
Electronic "Combination Lock".
Not the typical, keypad, or the push-button type.
More like , the round dial mechanical type.
Instead of a real mechanical dial, use a multi-turn potentiometer ("pot"), with a "turns counter".
The push-button type is better suited for alarms, garage doors etc..
The round mechanical dial, multi-turn potentiometer might be used for places without enough room for the keypad.
Most interesting, is the "retro look".
The turns-counter, looks like a typical combo-lock on a "safe" or vault.
The external foot-print would be smaller than a keypad.
The code:
Some of the code would be identical to the "resistor string", voltage divider style.
Where the A/D voltage, of a voltage divider, tells the microcontroller, which button is pressed.
This, would be a rotary dial, with a potentiometer (voltage divider), instead of a resistor string (voltage divider).
Same principle, except; minor mechanical "set-point" errors, would look like wider "tolerances".
I would like to get some ideas:
What types of algorithm do you suggest?:
How to make the lock field programmable.
Make the combination changeable.
How to allow for the mechanical accuracy (tolerance).
To tell the PIC that the operator is still turning the pot, hunting for the next "set point", or number. Then, when the movement stops for a certain amount of time consider that the "selected" number.
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This is not a needed, "must have" project.
More like, a fun "what if", thought experiment.
Why:
I have some fancy, 10 turn, potentiometers.
These are Bourns', "Knobpots®", with a turn's counter, dial built in.
There is a mechanical, 0 - 500 dial, like an odometer.
There are 4 markings (tick marks) between each of the 500 digits.
Round Dial, Electronic Combination Lock
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