3 ms·

My Topping DAC/Amp has an optical rotary encoder for volume control and it is awful, it will randomly jump 10x the amount of steps you have rotated it, sometime

My Topping DAC/Amp has an optical rotary encoder for volume control and it is awful, it will randomly jump 10x the amount of steps you have rotated it, sometimes even in the opposite direction. There's something to be said for a good old fashioned potentiometer.

formerly_proven 6y ago
It's kinda ridiculous that seemingly three quarters of the people who write graycode decoder firmware get it wrong, despite the correct methods being publicly available with sample code since 15-20 years at least.
- toomanybeersies 6y ago
  It's also an assignment that close to every electrical/computer engineer would have had to do as part of their degree. I guess you only need to understand ~50% of the course material to get your degree though.
- numpad0 6y ago
  Sounds like clicky 3-pin A/B bi-phase type though. I’ve done stupid things and tried to read that and two buttons with single ADC. That jumped around when Vref fluctuates.
YarickR2 6y ago
until it wears off or catches something between the slider and the base
lopmotr 6y ago
Potentiometers have that problem too when they get worn, which they always do if they also double as on/off switch like on most cheap radios.
- amiga-workbench 6y ago
  Yes, I keep a can of contact cleaner around to get rid of the oxidisation.
- dheera 6y ago
  They could use something like an AS5048A for 14-bit (effectively analog to humans) magnetic position sensing instead of a potentiometer or variable inductor. Considering they already need digital control circuitry to interface to a touch screen it shouldn't be significantly cost-prohibitive to use that to make knobs that are immune to oxidization.
  - numpad0 6y ago
    Kinda costly? I wonder if a dead simple 10kΩ B-curve potentiometer would do, though they drift a lot
- oasisbob 6y ago
  Just about every analog lighting board I've ever seen has huge dead zones on the end of the linear pots on some channels. I'm surprised the potentiometers work at all given the abuse they go through. Early desks had no memory, so it was often a huge rush to set the next scene in the fader bank before it was needed.
jope12 6y ago
An "optical rotary encoder"? I doubt it. I bet it's a mechanical rotary encoder. And that it randomly jumps means their code for reading the encoder sucks. Something like that should not happen if properly implemented. I will take a rotary encoder over a potentiometer every time.

formerly_proven 6y ago

It's kinda ridiculous that seemingly three quarters of the people who write graycode decoder firmware get it wrong, despite the correct methods being publicly available with sample code since 15-20 years at least.

toomanybeersies 6y ago
It's also an assignment that close to every electrical/computer engineer would have had to do as part of their degree. I guess you only need to understand ~50% of the course material to get your degree though.
numpad0 6y ago
Sounds like clicky 3-pin A/B bi-phase type though. I’ve done stupid things and tried to read that and two buttons with single ADC. That jumped around when Vref fluctuates.

YarickR2 6y ago

until it wears off or catches something between the slider and the base

lopmotr 6y ago

Potentiometers have that problem too when they get worn, which they always do if they also double as on/off switch like on most cheap radios.

amiga-workbench 6y ago
Yes, I keep a can of contact cleaner around to get rid of the oxidisation.
dheera 6y ago
They could use something like an AS5048A for 14-bit (effectively analog to humans) magnetic position sensing instead of a potentiometer or variable inductor. Considering they already need digital control circuitry to interface to a touch screen it shouldn't be significantly cost-prohibitive to use that to make knobs that are immune to oxidization.
- numpad0 6y ago
  Kinda costly? I wonder if a dead simple 10kΩ B-curve potentiometer would do, though they drift a lot
oasisbob 6y ago
Just about every analog lighting board I've ever seen has huge dead zones on the end of the linear pots on some channels. I'm surprised the potentiometers work at all given the abuse they go through. Early desks had no memory, so it was often a huge rush to set the next scene in the fader bank before it was needed.

jope12 6y ago

An "optical rotary encoder"? I doubt it. I bet it's a mechanical rotary encoder. And that it randomly jumps means their code for reading the encoder sucks. Something like that should not happen if properly implemented. I will take a rotary encoder over a potentiometer every time.