Not a Bug ADC Levels fluctuate on pedals not connected

leagueofkruger

leagueofkruger

Inspired
Ive noticed if I go into Setup/Utilities/ADC Levels the ADC value for Pedal1, Pedal2 and Pedal3 constantly fluctuate, even tho Pedal2 and Pedal3 are not connected?

FW7.00, any factory preset

I have an EV-1 connected to Pedal 1, so I would expect that to change (goes to zero if I press all way down, then up to 1005 when pressed all the way up, where it fluctuates back and forth between 1005/1004

But nothing is connected to Pedal2 or Pedal3 inputs, but I constantly see Pedal2 returning any of 1004/1003/1002, and also (but not as frequently) I see Pedal3 doing the same returning values of 1002/1001.

Is there any CPU being taken by continually checking the value of an ADC for something not connected? (Or is this expected behaviour and only being checked when on this utilities page?)
 
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leagueofkruger said:
Is there any CPU being taken by continually checking the value of an ADC for something not connected?
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The amount of CPU needed to check the value of a pedal is tiny compared to the CPU needed to do signal processing.

Besides, how would it know that you plugged in a pedal I’d it didn’t keep checking?
 
Rex said:
The amount of CPU needed to check the value of a pedal is tiny compared to the CPU needed to do signal processing.

Besides, how would it know that you plugged in a pedal I’d it didn’t keep checking?
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That seems fair, tho you could argue every little bit of savings adds up... I was really wondering if the bouncing around between values was happening all the time in the background and is "normal", especially on pedals that aren't connected.

The manual says this utilities page is to help with troubleshooting.
 
What you see as jumping is noise. If it were jumping between vastly different values, that would be an issue. Jumping between adjacent values is inevitable with any ADC.
 
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Hopper_ said:
Do you develop for FAS?
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No.

Hopper_ said:
This was a question directed at someone who could answer with any certainty at all.
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That's me. I've done software development at various times in my career. Polling a value and comparing it against a previous value is one of the easiest things you can do with a processor. It takes a handful of processor cycles and a couple of memory fetches — on a processor that can handle billions of cycles per second.

That's the worst case. In the best case, the polling is handled by dedicated hardware, and the CPU isn't even involved until the dedicated processor detects a change and generates an interrupt. In either case, the polling eats up a tiny fraction of 1% of the CPU capacity.
 
Rex said:
No.


That's me. I've done software development at various times in my career. Polling a value and comparing it against a previous value is one of the easiest things you can do with a processor. It takes a handful of processor cycles and a couple of memory fetches — on a processor that can handle billions of cycles per second.

That's the worst case. In the best case, the polling is handled by dedicated hardware, and the CPU isn't even involved until the dedicated processor detects a change and generates an interrupt. In either case, the polling eats up a tiny fraction of 1% of the CPU capacity.
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I just think it’s interesting to know how the Fractal units work.
 
Hopper_ said:
I just think it’s interesting to know how the Fractal units work.
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In general they work like any other data acquisition system. If they do this very differently, that's probably a bad thing. The magic is in the form and feature set, plus the algorithms.
 
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