[sdiy] Simple voltage controlled clock/counter

[Matthew Smith]

Quoth Justin Owen at 11/11/11 06:53...
> Hello,
>
> I have a need for a 'clock' of sorts - something to drive some counters, clock dividers and some other assorted logic bits'n'bobs.
>
> It needs to...
>
> Output a square wave between 0 and 5V-ish
> Voltage controlled and linear - i.e. if 1V = 100Hz then 2V = 200Hz
> Capable of low frequencies - say, approx. 10BPM (0.17Hz) to 300BPM (5 Hz)
> Ideally w/- PWM
> Some sort of sync or reset facility

If it's a square wave you're wanting, I'd definitely look at digital. 
Microcontroller with a single ADC channel for your control voltage (or 
with external ADC if internal resolution not adequate) and a GPIO for 
sync/reset. Use external crystal to get the accuracy you require.

Very little board real-estate, low-cost, and not even a hell of a lot of 
coding for something like that unless you want to add a load of features.

[BTW: still need to mail you about other stuff, but STILL catching up 
from week away last month.]

Cheers

M

-- 
Matthew Smith

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