Step / Direction support for stepper motor

[shifra1911]

New user here. I just got new Open FFboard, i cant find support for stepper interface. Do i need TMC4671 board to drive stepper or i can drive stepper without SPI, just with Step and Direction signals ? Thanks

[Ultrawipf]

Step/Dir drivers are impossible to use for FFB.
Actual torque control and FOC is required and most stepper drivers use a constant current.

For a stepper you will need the TMC4671 board.

[Ultrawipf]

No this driver does not support a torque control mode so it is not possible to use it for FFB. It can only correct missed steps in a position step mode using the encoder.

[shifra1911]

I got TMC46711 board finally. what could cause fps drop in Crew2 ? and its not recognized as racing wheel, do I need to configure something ? I also have 2 analog axes on A2 and A3 for brake and acceleration. that works okay and wheel with forces. but frames drop to 2-3 from 60... any suggestions ? thanks

[Ultrawipf]

Haven't tested that game. Maybe usb data is not received or acknowledged fast enough. Does it work fine with other games?
Try changing the update rate, maybe a slower rate helps?

[shifra1911]

Ive tried everything. At the end i downloaded Assetto Corsa just to test wheel and i was working almost good. turning to left was much softer than turning wheel right. Also i didnt experience when software endstops in game (but just in Assetto, i havent tested other games), my range was 900 degree like in game, but on turning left somwhere arround 160 degree wheel would become soft to turn and even would continute to turn by itself. even in configurator, wheel was acting strange. i used nema34 bioplar stepper, 50 pole pairs, with built in encoder of 600ppr (2400 in total) and after 15 minutes on assetto corsa wheel stoped working, configurator says TMC not found. Can you suggest what to do ? ive used stepper like you did in videos on youtube, power was arround 20-25%, im just confused, why it was behaving strange and why now stoped working. also diode on bottom of TMC was hot when wheel stoped working. when i come home i can provide more details...

[Ultrawipf]

That sounds like your encoder is losing the position and does not stay in sync with the motor phase. You might have serious electrical interference. With a stepper the encoder alignment is extremely critical and that encoder is very low resolution so even a few glitched encoder steps could flip the phase.
I would recommend checking if the connections are good, encoder cable shielded and connected to gnd, not too close to the motor wires, good power supply, maybe use a powered usb hub or usb isolator.
Maybe try to use ferrite beads on wires as well.