Floating voltage (Wobbly axis)

[agustin]

Hi friends. I´m new to the Teensy world but not on other MCUs.
I wanted to build a simple cockpit panel to control trims and radiators with slider pots. I hooked up a pot on a slider axis using the example sketch on Arduino, and all the sliders on joystick properties are wobbling like crazy. All other analog pins aren´t hooked to anything. But the pin where a pot is hooked still has some wobbling. Is this caused by floating voltage by induced eletromagnetic fields such as AC from the outlets for example? Should I attach the pins to VCC, GND with a resistor? What value should I use? I haven´t tried that yet since I´m not at home. anyways thank you to all!

 

[defragster]

You say Wobbly - but no idea how much that change that represents? Seeing instability in the lower bit(s) isn't surprising depending on the connection and environment.

Just saw this go by in past days - adding a CAP might help … Strange-analogReading-struggle-with-fader … the rest won't likely apply.

 

[agustin]

You say Wobbly - but no idea how much that change that represents? Seeing instability in the lower bit(s) isn't surprising depending on the connection and environment.

Just saw this go by in past days - adding a CAP might help … Strange-analogReading-struggle-with-fader … the rest won't likely apply.

It looked like noise caused by EMI. I didn´t have any caps and the rest of the pins were floating since I didn´t hook them to anything on the breadboard. I will try to hook all pins to VCC or GND respectively. I just tied the wiper of a linear 10K POT on slider axis just to see if it works. I will complete the project and I will update. Thank you so much!

 

[tonton81]

All pins are disabled by default, to put them in working floating state you must make the pin active via pinMode(pin, INPUT);

There shouldnt be a need to tie pins high or low as they’re disabled by default from being used

example of disabling a pin:

pinMode(13, INPUT_DISABLE); //disable led pin