What is the default pwm frequency(s) for arduino 018 and on what pins?
I have some older H-bridge boards that can only do up to 1khz and don't want to fry them...
Gavin 
Pins 3, 5, 6, 9, 10, and 11 act as PWM pins when you analogWrite to them. Then they will operate at whatever frequency you set them too.
See the hardware specs on the Duemilanove:
http://arduino.cc/en/Main/ArduinoBoardDuemilanove
The frequency of the PWM signal is approximately 490 Hz.
The pulse width is whatever you set in AnalogWrite, but the frequency is constant.
IIRC, it's about 1KHz on some pins, and 500Hz on others. I don't remember whether this is because two of the pins use the same timer as millis, or whether (a different) two pins are on a 16bit timer with somewhat different modes, or something else.
(confirmed with scope. 980Hz on 5 and 6, 490Hz on 3, 9, 10, 11)
Then they will operate at whatever frequency you set them too.
@ digimike: That's "to", and I don't think you understand the difference between "frequency" and "mark:space ratio".
Do you want ease up on the responses on stuff you don't understand?
Do you want ease up on the responses on stuff you don't understand?
@ AWOL: That's "Do you want to ease up...". lol
Then answer is yes I will try. In fact I'll try to re phrase my responses so if I'm wrong it can be easily pointed out and become a better learning experience for me as well.