fischertechnik community forum

Hi,

I want to control an XS motor by RaspberryPi. On Arduino I'm able to control the XS motor just fine by adjusting voltage as well as pulsewidthmodulation (pwm),

However, on the RPi the pwm doesn't fully do its job . I'm using 2 different pwm libraries. One recommended to control a pwm motor seems not to work. The other for controlling an LED does work but doesn't do anything on the motor. Which makes me wonder what the exact technical data for pwm is for the XS motor. Can someone tell me of should I ask ft support?

Thanks,

hvn

Hi,

Do you directly connect the XS motor to one of the PWM GPIO Pins of the Raspberry Pi / Arduino? If yes, you can badly damage your microcontroller because the current might be too high.

If no what kind of H-bridge / Relais / MOSFET do you use? Basically, a PWM library to fade a LED should be fine as long as the transistor is supplied with 9 Volts.

Best regards
David

Hi,

No..never directly. Whenever I connect something to the GPIO, there's always at least a resistor in between. In this case, there's a resistor/transitor circuit between the GPIO and the motor as recommended by various info sources. I would prefer an H-bridge, but the hardware I found online isn't/wasn't available anymore. Still stands the question: since the (RPIO.PWM) library has been tested (by someone) it apparently works. And yes, the LED gives no problem (wiringpi library).

Thanks

hvn

Hi,

do you use PWM-frequencies in kHz-range?
Try out 100-200 Hz (not kHz)

Hello hvn,

technical data about the XS (137096) you find here: https://www.ftcommunity.de/data/downloa ... 96_neu.pdf

Regards
H.A.R.R.Y.

Hi thkais and H.A.R.R.Y.,

Thank you for the information.

hvn