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Unable to connect to Arduino Mega 2560 via USB

Posted: Wed Aug 21, 2019 10:39 am
by Venom501
Hi,
I've been working on my project the last few days and everything worked fine. I am using Megunolink as a GUI to create input via buttons and value lists to control my device.
Till yesterday I got no problems, but when I tried to connect Megunolink today, it wasn't possible to establish a serial connection.
The "connect" button did nothing. And when pressing some Buttons, I get the message "Error sending: can't write to serial channel. Is it open?"
Uploading my programs with the Arduino IDE works as usual. (I tried different programs)

When opening a backup .mlpz-File from yesterday, the connection is established and everything works as intended. But when disconnect once, I am not able to reconnect.
After loading the backup file again it works till the next disconnect.

Re: Unable to connect to Arduino Mega 2560 via USB

Posted: Sat Aug 24, 2019 2:56 am
by philr
Hi, do you have a MegunoLink license? Those are the sort of symptoms you get when an invalid license key is used. Get in touch with use as support@megunolink.com with your transaction information and we can try to figure out what the issue is.

Cheers
Phil

Re: Unable to connect to Arduino Mega 2560 via USB

Posted: Fri Oct 04, 2019 2:17 pm
by DrewRu
Hi...the only difference between your working Uno configuration and your non-working Mega configuration is the board? It's plugged into the same computer in the same USB port?
If it doesn't show up at all in Device Manager that indicates the problem is not with the bootloader on the ATmega2560. That problem would only show up once you attempted to upload a sketch to the board. The problem is more likely with the ATmega16U2 that handles the USB to serial conversion. You could try uploading the firmware to that chip.

pcb assembly

Re: Unable to connect to Arduino Mega 2560 via USB

Posted: Mon Oct 07, 2019 8:42 am
by philr
Hi DrewRu, we got it sorted in the end. Was incorrectly registered. Once the code was entered properly all was well.

Cheers
Phil