Issue uploading code with Optiboot for Mega 2560 about my_boards HOT 12 CLOSED

which Optiboot version did you 'burn'?

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I downloaded my_boards 2 days ago, and I have problems uploading "big sketchs" if i try upload an empty sketch does not fail

from my_boards.

I downloaded my_boards 2 days ago, and I have problems uploading "big sketchs" if i try upload an empty sketch does not fail

you mean usb upload like in the post above? there a small sketch fails

from my_boards.

True, I seemed to see that correlation at one point, but it's not true, it's random. Or at least, it fails more likely on large sketches than small ones and occasionally loads and checks correctly

from my_boards.

Optiboot uses higher baud rate. maybe try a different USB cable

from my_boards.

I have already tried 3 different cables...I have a Mega2560 board connected to an ESP12F through the Serial1 channel communicating with each other with the WifiEspAT library. I got it to work, but since a week ago I can no longer upload code to the Mega2560 (is not exact, When I receive the error reading the code in the last step of the uploading process, if I open the Serial monitor, seems that the code is right uploaded, the upload error it's maybe only in the reading check process).

I too have tested with 2 diferent PCs, with several Mega2560 boards and with several ESP12F and in all cases I get the same error in the data upload process.
I have also tried the latest version of my_boards to burn the bootloader of the board, but before it was working correctly with a minor version... (Without having updated apparently nothing started to fail with the old my_boards and that is why now I have updated and it continues to fail)

The failure is random, depending on the size of the sketch the probability of upload failure increases (I have tested it with a blank sketch and an estimated 30% of the uploads fail. With the Arduino's "blink" example the probability of failure is close to 50%, with a slightly heavier skech the failure appears in 90% of the rises)).

It also increases the probability of uploading the data correctly if we disconnect the ESP12F of the Mega2560 during the upload...

But after trying several times the code upload finally always ends up giving the upload error...

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is it a Mega with 16u2 as USB, or CH340? how is the esp-12F powered?

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Mega have CH340 and i have tested with esp-12f powered since the Mega (first, powered only using the USB and after powered Mega with an aditional power suplpy) and also tested with esp-12f powered an external power supply

from my_boards.

115200 baud is suboptimal for Mega and maybe the CH340 makes it worst (or 16u2 helps).
you could try Optiboot with a different baud rate. the Mega Core has them ready. (Optiboot in Mega Core has the copy_flash_pages function for ArduinoOTA)

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Can you recommend a suitable transmission speed? And could you explain how I should change the baud rate of the USB flash?

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I looked up a the baud rate for Arduino Mega with the default bootloader.. It is 115200 too. so it can't be a problem with the baud rate. sorry

from my_boards.

Hello, I have found the origin of this issue, the problem is a problematic Mega 2560 PRO board assembler. Not only does it give firmware loading problems but it also has the inverted ICSP silkscreen. Seen from the photo, 5V, MOSI and GND appear on the right and are the ones on the left.
Sorry for the disturbances. I hope this report serves more people

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