I've uploaded a project and am writing some data to the SD card to monitor what happens. It's been running all night and all day. Today I see the Led on pin 13 is blinking very fast. I have omitted use of this pin so I assume this could be a way to show a common fault? The program has the watchdog enabled so if there is a failure I would assume it will reboot but this doesnt seem to be happening.
Does anyone know if this is trying g to tell me something is wrong?
How long is the watchdog delay?
Could it have done watchdog reset - but the WDT is still enabled, so before the bootloader passes control back to the sketch (which is aware of the watchdog timer and knows to reset it), it resets again, and you're seeing the bootloader's blink repeatedly?
I think it may have overheated due to a poor quality power supply causing the voltage regulator to work it's tits off. It's mounted under two shields and in a box.
I'll try a USB plug and power it via USB at the correct voltage and bypass the voltage reg
See if you have the same voltage regulator this other forum member has:
If you do, that would be bad news.
Also, if you are using adafruit's sd logging shield, you ARE using pin 13 as a pin for software SPI communication with the SD card. It would flash too quickly to be seen as blinking though.
I'll check tomorrow. Pin 13 was blinking too slow for comms
No I don't have that voltage reg. So hopefully that's good. Going to leave it running again on usb this time.
So it looks like it will have been the voltage reg. I've had it on a USB power supply for the last 12 hours and it's barely warm. On the other power supply the box that contains the mega was even hot.