Serial Port not found - Seeeduino Lotus Cortext M0+

[h.e.m.van.vugt]

Hi All

My students are using Arduino IDE and Seeeduino Lotus Cortext M0+ (185 pcs.). Now the serial port of 14 of those boards is not found.
I can’t select the Serial Port via Tools > Ports*

How can I fix this?

These boards worked before. I found I can get boards manually into bootloader mode (doubleclick the Reset) But this does not work with the failing boards.

This is the problem (board/port not found - MAC):

It is not the Computer or USB cable, same setup with other Seeeduino works perfect - same MAC:

Thank you so mutch!
Hermanus van Vugt
(University of Amsterdam)

[jiachenglu]

Hi @h.e.m.van.vugt
Have you used 1.8.0 version SAMD before? The bootloader interrupted which will need to re-flash the bootloader.
Please refer to the below forums.
Seeeduino Lotus Cortext M0 - 15 Pcs dead after uploading first code

Odyssey x86j4105 ubuntu 20.4 no /dev/ttyACM0 and no seeeduino listed under lsusb

The uploading process interrupted the bootloader of the Arduino Core. Do you have any other SAMD arduino boards around? You can use this SAMD board to flash the bootloader back in the ODYSSEY.

[h.e.m.van.vugt]

Thank you

It looks you are right, it is caused by 1.8.0. Explained in this post:

Seeeduino Lotus Cortext M0 - 15 Pcs dead after uploading first code

Hi @h.e.m.van.vugt Sorry for this issue caused.

They provide a ‘solution’ to the problem. But It is far too complex and will take me more than a day. I have to wait till someone writes a more specific howto for this situation. ;-(

[jiachenglu]

Hi @h.e.m.van.vugt
If you have a raspberry pi then you can consider this way to solve it.