Is it possible using an arduino to control more than 4 PWM fan at 25khz ?
I have found this but 4 PWM limited with an UNO
An other arduino, like a 2560 could be used ?
Thanks Best regards Sébastien
Indeed you could use a Mega. See this answer: it explains how you can use Timer 1 on an Uno to provide two PWM channels at 25 kHz. This is the only 16-bit timer on that board. The Mega, on the other hand, has four 16-bit timers: Timers 1, 3, 4 and 5. These timers are almost identical to the Uno's Timer 1, except that they provide 3 PWM channels each. So you have potentially up to 12 PWM channels that you can run at 25 kHz.
Now, look at this pinout diagram. Every pin labeled
n is either 1, 3, 4 or 5, and
x is a letter, is a 16-bit PWM
output. Just take the code from the answer I linked to and adapt it to
the Mega. You configure all those timers in the same way, and you set
the duty cycle for pin
OC3B by writing to the register
OCR3B (and so