Okay. So I figured out why it dosen't work if you set the register. It turns out that not all the pwm pins is actually pwm pin, some are timer pins. So for example doing:
'PWM->PWM_CLK = 0b00001010111111110000101011111111;'
Works for pin 6, but not pin 2. (Tho you need to do it after every analogWrite as analogWrite insist on the 1k freq)
Another easier way to change the freq is to do:
'PWMC_ConfigureClocks(whatever_freq_you_want * 255 , 0, VARIANT_MCK);'


From variants.cpp:

Code:

 ....
  ....
  // 0 .. 53 - Digital pins
  // ----------------------
  // 0/1 - UART (Serial)
  { PIOA, PIO_PA8A_URXD,     ID_PIOA, PIO_PERIPH_A, PIO_DEFAULT,  PIN_ATTR_DIGITAL,                 NO_ADC, NO_ADC, NOT_ON_PWM,  NOT_ON_TIMER }, // URXD
  { PIOA, PIO_PA9A_UTXD,     ID_PIOA, PIO_PERIPH_A, PIO_DEFAULT,  PIN_ATTR_DIGITAL,                 NO_ADC, NO_ADC, NOT_ON_PWM,  NOT_ON_TIMER }, // UTXD

  // 2
  { PIOB, PIO_PB25B_TIOA0,   ID_PIOB, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM,  TC0_CHA0     }, // TIOA0
  { PIOC, PIO_PC28B_TIOA7,   ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM,  TC2_CHA7     }, // TIOA7
  { PIOC, PIO_PC26B_TIOB6,   ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM,  TC2_CHB6     }, // TIOB6

  // 5
  { PIOC, PIO_PC25B_TIOA6,   ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM,  TC2_CHA6     }, // TIOA6
  { PIOC, PIO_PC24B_PWML7,   ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_PWM),   NO_ADC, NO_ADC, PWM_CH7,     NOT_ON_TIMER }, // PWML7
  { PIOC, PIO_PC23B_PWML6,   ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_PWM),   NO_ADC, NO_ADC, PWM_CH6,     NOT_ON_TIMER }, // PWML6
  { PIOC, PIO_PC22B_PWML5,   ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_PWM),   NO_ADC, NO_ADC, PWM_CH5,     NOT_ON_TIMER }, // PWML5
  { PIOC, PIO_PC21B_PWML4,   ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_PWM),   NO_ADC, NO_ADC, PWM_CH4,     NOT_ON_TIMER }, // PWML4
  // 10
  { PIOC, PIO_PC29B_TIOB7,   ID_PIOC, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM,  TC2_CHB7     }, // TIOB7
  { PIOD, PIO_PD7B_TIOA8,    ID_PIOD, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM,  TC2_CHA8     }, // TIOA8
  { PIOD, PIO_PD8B_TIOB8,    ID_PIOD, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM,  TC2_CHB8     }, // TIOB8

  // 13 - AMBER LED
  { PIOB, PIO_PB27B_TIOB0,   ID_PIOB, PIO_PERIPH_B, PIO_DEFAULT, (PIN_ATTR_DIGITAL|PIN_ATTR_TIMER), NO_ADC, NO_ADC, NOT_ON_PWM,  TC0_CHB0     }, // TIOB0

  // 14/15 - USART3 (Serial3)
  { PIOD, PIO_PD4B_TXD3,     ID_PIOD, PIO_PERIPH_B, PIO_DEFAULT, PIN_ATTR_DIGITAL,                  NO_ADC, NO_ADC, NOT_ON_PWM,  NOT_ON_TIMER }, // TXD3
  { PIOD, PIO_PD5B_RXD3,     ID_PIOD, PIO_PERIPH_B, PIO_DEFAULT, PIN_ATTR_DIGITAL,                  NO_ADC, NO_ADC, NOT_ON_PWM,  NOT_ON_TIMER }, // RXD3
   ....
   ....
  

As you can see only pin 6, 7, 8 and 9 is a PWM_CH pin.
You can surely change the freq on the timer pins too but I'm too tired to dig into that.

I'd say that the analogWrite need to be changed so that it allows easier change of the freq.

Edit:
If you don't want to set the freq for every analogWrite you could use 'PWMC_SetDutyCycle(PWM_INTERFACE, PWM_CH7, your_analog_write_value);' instead.
So a fading led sketch with 4k pwm freq on pin 6 would be:

Code:

void setup()  {
  pinMode(6, OUTPUT);
  analogWrite(6, 64);
  PWMC_ConfigureClocks(4000 * PWM_MAX_DUTY_CYCLE , 0, VARIANT_MCK);
}

void loop()  {
        for (int i = 0; i < 253; i++) {
            PWMC_SetDutyCycle(PWM_INTERFACE, PWM_CH7, i);
            delay(10);
}
for (int i = 255; i > 1; i--) {
            PWMC_SetDutyCycle(PWM_INTERFACE, PWM_CH7, i);
            delay(10);
}                
}

Had a quick look at it and I can confirm that changing PWM_FREQUENCY in
https://github.com/arduino/Arduino/blob/ide-1.5.x/hardware/arduino/sam/variants/arduino_due_x/variant.h#L182 does change the freq. So if you just need the 4k freq it'll work fine. Still, a way to change the freq in the sketch would be preferred.

nice!..

wher are all the other components?

I never used an ATtiny2313 before...

(still need the caps/crystal...etc?)

There is no need for any external components, and no attiny/atmega dosen't even need a crystal. They (atleast all I've used) have an 8MHz internal crystal. All you need is voltage and ground.

Was bored so I tried to make a tiny attiny2313 (DIP) board with ISP headers. Here is what I got:

Impressive project! Would be sad to see you giving up the due for such a basic thing as changing the pwm frequency. The IDE does set the freq in some library, you could try to look for it and change the freq the same way the arduino guys have done. But I'm sure someone already have tried to change the freq and can show you how, it's just hope that such a person shows up . I might give it a go tonight if I find some free time.

Try "ant clean" first.

Thank you, it worked.

... but now I feel stupid. Got any ant argument for that?

Not fun. (Newest from git, linux64)

I think a missing crystal is a huge difference. Especially for people who wanted to use the SAMs RTC.

Yes, well if they added the crystal I'd have to agree that it makes a difference, but they have removed it so there will not be any support for using it. Has someone actually gotten a board with the crystal? If then it's just a very small number of boards that has it.

(Don't get me wrong, I'd like the crystal too. But I'm sure they had their reasons for removing it.)

and why they sold out this board??? We bought all together at the same prize, the SAME board... but they are different...

The differences are so small that it doesn't matter.

My Due has the chip on the same place as 'the current one'. If you live in EU this place got 3 Due in stock http://www.robomaa.com/index.php?main_page=product_info&cPath=1001_1020&products_id=1245

Python is a scripting language...                               No.

Great to see new people getting interested in microcontrollers .
First, you have resistors in there too right?

Anyway.
You can change 'timer' in the loop as you like. For example:

Code:

void loop() {
  // loop from the lowest pin to the highest:
  for (int thisPin = 2; thisPin < 6; thisPin++) {
    // turn the pin on:
    digitalWrite(thisPin, HIGH); 
    delay(timer);
           
    // lower the delay if timer >= 20       
    if (timer >= 20) {
      timer = timer - 10;
    }

    // turn the pin off:
    digitalWrite(thisPin, LOW);   
  }
}

This will lower 'timer' by 10 each time the loop runs until 'timer' is 10 (milliseconds).
Have fun!

Since you are just using voltage[i-1] and voltage you don't need N to be bigger that 2. Get rid of the for loop and do 'voltage[1] = voltage[0];' and then 'voltage[0] = analogRead...' and so on.

"if (voltage-voltage[i-1]>=0.1)" in a loop with voltage constantly updating would result in a blink that you would probably not even notice.

You want to know the MIN current it has to provide. It says in the link I provided: 40mA per I/O pin (max). There are 86 I/O pins (from what I understand). That is 3440mA, + 500mA that the 3.3V pin can provide, that is 3940mA -> ~4A, so your power supply must provide AT LEAST 4A. I think you should go for 5A so you are on the safe side.

Edited because I forgot the 16 analog inputs pins in my calculation, and I'm not even sure I'm right but you get the idea . Please note that I'm nowhere near a specialist, I'm beginner like you!

If you would pull 4A from the AVR you would kill it. If you take a closer look at the datasheet it says:

ATmega640/1280/2560:
1)The sum of all IOH, for ports J0-J7, G2, A0-A7 should not exceed 200mA.
2)The sum of all IOH, for ports C0-C7, G0-G1, D0-D7, L0-L7 should not exceed 200mA.
3)The sum of all IOH, for ports G3-G4, B0-B7, H0-H7 should not exceed 200mA.
4)The sum of all IOH, for ports E0-E7, G5 should not exceed 100mA.
5)The sum of all IOH, for ports F0-F7, K0-K7 should not exceed 100mA.
If IOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current
greater than the listed test condition.