Did I just kill my Arduino Due by selecting the 32khz external crystal?

Hello there... I have been using an Arduino Due for about 3 months. Nevertheless I still consider myself a noob.

In summary I've been using this board with no flashing problems since I bought it. Probably flashed it like 200+ times already. I use both the Arduino IDE as well as AtmelStudio though I use AtmelStudio most of the time for its ASF.

So flashing was no probs until recently when the Bossac tool keeps displaying "No device found on COM20". I get this error message when flashing from the Atmel IDE. Same error when I try to Upload from the Arduino IDE.

I tried holding the ERASE button but it still doesn't work.
Tried with another Arduino Due board, this other board can be flashed just fine (Windows recognizes this as COM21 though).

The last thing I did was flash and run the RTC example project that came with AtmelStudio's ASF. The code was working fine when I used the default internal RC oscillator. But I decided to change the code to use the external 32kHz crystal instead to get better accuracy. Then the problem started...

It looks like my problem is permanent. Is there any way to fix this, like maybe reflash the ATMEGA16U2 or something like that??


Perhaps a bit late to respond... And: I'm not sure about this... But then again: when reviving 'the dead' there is usually nothing to loose :slight_smile: .

Looking at my due board, and at many of the www-pictures of due boards, I find that quite a few due boards simply don't have the 32 KHz xtal installed. The xtal 'should' be located next to the '.cc' of the "www.arduino.cc" printed on the due board.

If the xtal is missing, that could explain why yours is 'dead' after selecting the 32 KHz xtal as clock source. I expect that the clock source is 'burned'/configured to flash of the controller, and without an actual xtal, the result is that the due is bricked until further notice: it has no clock at all.

If so: The good news is that the board can probably be revived/'unbricked' by doing little more than installing the missing 32 KHz xtal (+ capacitors).

Reading from the due schematics, the pins 48 & 49 of the CPU chip is where the xtal should be connected, with two 22 pF capacitors. Again looking at the available www-pictures of due boards: many do actually have the empty pcb pads needed to install the missing 32 KHz xtal + capacitors.

FYI: any old watch can provide a 32 KHz xtal :slight_smile: . Perhaps not one as nice as an 'original', but for unbricking, that may very well be good enough.... If used only for unbricking, you may also try skipping the 22 pF capactitors: they are usually aimed at ensuring a proper and clean start-up of the 32 KHz xtal oscillator each and every time.

The 'nice' solution would of course be to find a matching 32 KHz smd-xtal, 2 x 22 pF smd-capacitor, an assembly-microscope and a suitably small soldering iron and add the missing components. If you really want to knock yourself out: additionally 'lift' pin 52 from the board, and connect a 3 Volts backup battery: The due controller chip has a real-time-clock inside. With a crystal and a backup battery, that could be used to keep time.