POT-meters spiking

[1.JaVA_Platypus]

As some of you might know, I do have several USB input boards with additional buttons and axis programmed for DCS. I do use standard cheap pot-meters (100Kohm) However, the output is spiking somewhat on each and everyone of them. They are all relative NEW Potmeters so it is not wear and tear that is causing the spiking. It is just because of the cheapness of the components. I was thinking about filtering-out spiking on the pot-meters using an RC low-pass filter. Will this work for leveling-out the spiking?

 

This guy sells some kind of add-on PCB for Logitech racing pedals. He seems to be using some kind of RC filter with a simple IC.

 

I want to make some electronic filtering for my pot-meters as well. But I don't know wich Condensators or resistors to choose.

 

http://www.basherboards.com/Pedals_PF1_Explained

 

My input-boards...

 

[Sokol1_br]

I read in Spanish forum that for USB controllers:

 

A high K pot (above 50k) take less amperage from USB - what can be desirable if used many pots - but are more subject to induce spikes.

 

A lower K (10~50k) will take more amperage, but is less subject to spikes.

 

Length cables between the pot and the controller can pink noise.

 

A good cable is "MGTF wire" used in telephony.

 

http://www.pentod.com/en/product/524...mgtf-ussr.html

 

In MMJoy2 are a filter to be set in firmware to deal with spikes.

[1.JaVA_Platypus]

Length of the wires between the pots and the BU8036X is measured in centimeters. (see pic above) And they are enclosed in an earthed metal box. But exchanging the 100K pots with 20 or 30K's is a useful hint.

[1.JaVA_Platypus]

ps... can the MMjoy2 firmware be used on the LEO Bodnar BU8036X board?

[Sokol1_br]

No, BU0836 have bootloader locked, besides that MMjoy2 code are done for AMEGA and BU0836 use Microchip mc. :)

[KLR Rico]

I'd try keeping the high value pots and add a capacitor (~1uf) between the wiper and ground. It'd be easy to try because you can just solder it right there on the pot.

[1.JaVA_Platypus]

I'd try keeping the high value pots and add a capacitor (~1uf) between the wiper and ground. It'd be easy to try because you can just solder it right there on the pot.

 

Maybe there is still room on the BU8036X to just plug them into the clamps together with the wires. Thanks for the suggestion.

 

[SinusoidDelta]

In addition to adding a cap verify that all potentiometer ground meet at a single point. I don't know if it's possible in your application but an FFT could filter out spikes.

[1.JaVA_Platypus]

In addition to adding a cap verify that all potentiometer ground meet at a single point. I don't know if it's possible in your application but an FFT could filter out spikes.

 

I do not know what a FFT is. But I guess Leo Bodnar uses the same 'ground' on his board for all his analogue inputs. In the end, I think everything (is/should be) tied to the USB PIN 4 on any USB board. I will verify that later this evening.