While making some program changes on my project, an intermittent USB cable seems to have rendered the 32U4 on this Leonardo-Compatible ElecFreaks board useless. It seems it has asserted itself to "BRICK MODE". The unit was working just fine allowing uploads using Com7 with WIndows_7. I've done some looking and think I can upload the "bootloader". I also have a working board and it communicates just fine with the IDE.
My question is about the IDE and bootloader. I assume the Leonardo uses a different bootloader from other Atmel devices. Am I to assume the IDE will upload the CORRECT bootloader for the 32U4 since I have "Leonardo" selected for the board? Also, I'm running Version 1.5 of the IDE to let me be DUE compatible. How do I know what gets 'burned' is the correct version when I tell it to "burn bootloader" in the IDE?
What are you actually going to use to burn the bootloader? Are you using an ISP programmer, or a UNO or another Leonardo to do it?
{I don't know how an intermittent USB connection could affect the bootloader itself, but I suppose it is remotely possible with a Leonardo. I think you would need to check all alternative possibilities first, the most obvious of which being that the COM port has been reallocated.}
I actually own both another Leonardo AND an ISP programmer. Haven't used the programmer at all, I bought it for another project that used an ATTINY which obviously has no bootloader. As for the symptoms, the other Leonardo works just fine and the PC recognizes it as COM7 with COM3 showing up but unchecked. When I plug in the BRICK though it comes up for a moment as COM8 and then goes away after the normal 7-8 seconds, showing only COM3.
As for how it became a BRICK, I was in the middle of uploading a new sketch and noticed the PWR LED went out for a moment. I can't imagine the actual sketch clobbered it.
When I reset the "BRICK", COM8 appears briefly (2 sec) labelled as "bootloader". However I'm not able to burn the bootloader when it says that. Also, the LED blinks just as if it were scanning for a com port. I haven't been successful in either attempt at burning the bootloader "USBasp" or Arduino as ISP.