I was testin motors and I put motor speed to top in motor example code and i put 5v to 0v on/off switching like max speed (maybe mhz??) . Motor made weird high noise. Then i wondered that can arduino cause ultrasound noise or any other kin of fysic radiation with motor? Who knows about it? its weir and i m interested
Motors generate all kinds of of noise: audible, inaudible, electrical and radio frequency noise.
Do not try to power a motor or servo from an Arduino. The Arduino will malfunction and might even be destroyed. Always use a separate motor power supply and connect the grounds.
Okay. Do you know if those noises and radiations can be dangerous? (for example to hearing)
Yes, motors can certainly be dangerous. But it is unlikely that a small toy motor will damage anything other than the Arduino, if you use a separate power supply.
milli hertz? 'm' is milli, 'M' is mega, you need to get such things right in electronics!!