Originally Posted by JNJO
Big scare yesterday, when I ripped off my USB-connector.
(Don't ask how...It involved a cable twisted around my leg and a ringing phone....
Anyway, managed to re-attach it (Damn, those SMD:s are small
...), but it looks like I toasted the CP2102 USB to serial chip in the process.
Uploading through an FTDI on TX0 didn't work either, but then I found a very well hidden post by Sir Alex, saying that the CP2102 chip had to be removed for that to work.
Did that, and now all is well again. Sort of....
To upload firmware through TX0, I have to burn the boot loader with arduino and an USBavp on the ISP-header first. Propably a fuse bit that needs changing.
And for now, I lost my terminal in APM.
Darn, bad luck.
The only thing stopping Arduino upload using J2 FTDI socket Hk Mega board is that there is NOT a 100nF capacitor from the J2 socket DTR to the RESET pin on ATMega2560 [Pin 30].
Arduino uses a pulse on DTR to pulse the 2560 RESET via the capacitor, that resets the 2560 and Arduino starts upload before the 2560 times out and boots the application firmware.
I have just uploaded a sketch to HK Mega using FTDI cable connected to J2, no chips removed no different boot loader, no changes at all to the board powered from FTDI cable USB not connected.
Watch the Arduino status line when it changes from "Compiling sketch" to "Uploading " quickly press and release the HK Mega board's Reset button and LED1 should flicker until the upload is completed.
If it doesn't then first power cycle the board by disconnecting the USB end of the FTDi cable so Arduino sees an error and quits trying to "Upload"
then try again to get the timing of pressing the Reset button right.
Terminal on APM, click on Terminal button, as soon as white text appears press ENTER key 3 times, it does work from J2, I have tried it, it works.