Hi,
(Sorry if my english bad, I do not whrite or speak in english very often)
Today, I was working on my projet when suddently my PC lose connection with Arduino Leonardo.
There still power going to the board because the ON LED is on but nothing else. my program that was working a second ago does not anymore. my lcd sceen just have the backlight on. On my PC, I search in the Device Manager ook under Ports (COM & LPT) and ther no arduino anymore and there nothing under Other Devices. When I press the reset button on my board, Arduino Leonardo bootloader (COM5) appears for 5 sec. in Ports (COM & LPT) but I can't do anything with it.
Any help would be appreciated.
Are you able to upload if you select COM5 and press reset during the upload process, so at the point it's trying to start talking to the board, the board is in bootloader mode?
It sounds like you did something in your sketch that broke the USB. Not experienced with the native USB ones, so not sure why that happened, but it doesn't surprise me that a bad bug could trash USB functionality while the sketch is running.
DrAzzy:
Are you able to upload if you select COM5 and press reset during the upload process, so at the point it's trying to start talking to the board, the board is in bootloader mode?
It sounds like you did something in your sketch that broke the USB. Not experienced with the native USB ones, so not sure why that happened, but it doesn't surprise me that a bad bug could trash USB functionality while the sketch is running.
No, I try to upload on COM5 and it didn't work. For the bootloader mode question, I don't know. I didn't what bootloader mode was before I broke my arduino.
And for the broke USB funtionality, there probably no way to physicaly do a factory reset is it?
Are you sure you got the pressing of reset timed right? You would need it to be in that brief reset window at just the right moment (normally, the IDE is able to reset the board automatically, but because your sketch hosed the USB, once the sketch starts running, it can't reset it, and hence can't get into the bootloader. So you need to time a reset perfectly to get a new sketch on it). Once you get a new sketch on it that doesn't do whatever it was that broke USB, I think it'd work again.
Worst case, re-upload the bootloader using Atmel FLIP and DFU (I think that's supported on the Leo? Not sure - I haven't used the 32u4 much), or via ISP, and that should fix it.