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ranenbg / Arduino-FFB-wheel

Stand-alone DirectInput USB device recognized in Windows as a joystick with force feedback functionality, based on BRWheel by Fernando Igor from 2017.
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Deadzone in inputs? #53

Closed RandomHuman97 closed 5 months ago

RandomHuman97 commented 5 months ago

When I try to turn the wheel, there is a very noticeable dead zone (the encoder moves and pulses, but the wheel doesn't send it as an output), is there any way to disable/lessen it?

ranenbg commented 5 months ago

Hi, you are probably refering to the FFB deadzone around wheel center when autocenter spring force is active.

The cause of this issue is not in my firmware or arduino, but in the way how a DC motor operates. It simply needs some minimal voltage/current to overcome friction and make it start spinning. Especialy once you put motor into a wheel, where you add much more friction due to all bearings/gears/belts/wheel inertia and so on, you need some additional current to make the motor spin from a stand still.

In my firmware I made a setting to compensate for this motor startup current. You will see a slider in wheel control GUI named "min pwm torque", which does exactly that. Its available range is from 0% to 20% and you will have to play with it to find a sweet spot. Start with about 5% and go higher from there. What you want is to minimize the ffb deadzone around center, but prevent any small oscilations, so it's a trade off. You can adjust it with 0.1% increments to really fine tune it, but be aware that this will also depend on pwm frequency and general gain slider value, so make sure you have set those two first to some desired or optimal value. For PWM freq I recommend 8kHz, while general gain is a matter of your prefference.

RandomHuman97 commented 5 months ago

Nevermind, I was talking about the rotary encoder deadzone, but turns out it was a software issue.

ranenbg commented 5 months ago

There is no software or firmware issue with the encoder. You probably had a hardware issue with incorrect wiring. Make sure to use pullup resistors and to connect them correctly. I've provided a wiring diagram.

Next time if you post an issue, please put some more effort to precissely describe the problem, as we can get to the solution much faster and help others solve their similair problems also.

Since you didn't say which encoder you have and what you did to solve it, I assume it was about incorrectly set encoder CPR. I hope you are not using a mechanical rotary encoder, as other than having a very small CPR, they will wear quite quickly and fail.