I use the connection in attachment but without variac.
Other thing I noticed is if I use analogWrite(pin, 255) the motor is not fully ON (compared to speed achieved by linking gate of IRFZ via resistor in picture directly to +5V)?!
I call MowerSpeed(255); or with 0.

const int Mower = 12;

void MowerSpeed (unsigned char MowerSpeed) {
  //0-255   0=off  255=full on
  if ((SoftStart == (SoftBOTH - 1)) || (MowerSpeed > 127)) {
    for (unsigned char a = 0; a < MowerSpeed; a++) {
      analogWrite(Mower, a);
      delay(10);
    }
    SoftStart = 0;
  }
  analogWrite(Mower, MowerSpeed);
}

Tnx in advance.

The pin is PCI28/OC1B/(Digital 12)/PD4/pin18 on ATMEL ATMEGA644P/SANGUINO.
So: pin=12.

I checked wiring.h and wiring_analog.c for sanguino and everything is OK. Translates to:
sbi(TCCR1A, COM1B1); // connect pwm to pin on timer 1, channel B
OCR1B = val; // set pwm duty

PWM works great at >0.

Pure pin, only arduino/uC, hanging in the air.

Hi,
I am trying to drive a motor via PWM, but when I want to turn it off using analogWrite(pin, 0), I can stil hear hum from the motor. If I measure voltage on the PWM pin (nothing attached on it i.e. only uC pin) it reads 0.104V. It makes no change if I set the pin as output or not. How to solve it?

If this problem cannot be overcome, how to exchange analogWrite and digitalWrite? The following does not work:
pinMode(pin, OUTPUT); //=in Setup. Not needed for analogWrite
if (Speed == 0) {
 analogWrite(pin, 0);
 digitalWrite(pin, 0);
} else {
 //digitalWrite(pin, 1); ?!?!?!? what to do here?
 analogWrite(pin, Speed);
}

Hi.
Has anyone tried Arduino on AVR-NET-IO from Pollin? ATmega644p. Any source code?