MKR WAN 1310 USB Voltage Tolerance

Official Hardware MKR Family MKR WAN 1310
1

A question about the tolerance of Arduino devices for variations in USB voltage:

My Arduino Uno R3 microcontroller boards are several years old and have seen a lot of use. They continue to work fine. My Arduino MKR WAN 1310 microcontroller boards are only a few months old and have suddenly stopped working. They are no longer recognized by the IDE, nor by a port-listing program written in Python. This is true when connected to my PC and RPi v4.

Have tried pressing the reset button and depowering/repowering the devices. The indicator LED does come on.

The USB ports on the PC and RPi generate voltages at the high end and a bit beyond the USB standard. Is it possible that the MKR device is burned out, whereas the Uno is more flexible? If not, what else could cause something like this?

This question impacts a GitHub project in LoRa P2P communication: GitHub - SoothingMist/Scalable-Point-to-Point-LoRa-Sensor-Network: Builds a peer-to-peer network of LoRa transceivers for remote sensing. Uses flood-messaging to eliminate need for LoRaWAN and third-party services..

Many thanks for the community's discussion.

2

Found this topic: MKR WAN 1310 no longer shows up in port menu - #2 by pert.._gaNDkyMTk1NDExLjE3NDMzNTYzNTc._ga_NEXN8H46L5MTc0MzM1NjM1Ny4xLjAuMTc0MzM1NjM1Ny4wLjAuMjAzNzgyNTQ1

Following this advice, the MKR is now recognized by the IDE. Will proceed now and post further results.

4

Later, after successfully used for awhile, the IDE (latest Arduino 1.x) went again into "port not found" mode. Tried the double-reset again. The yellow LED came on. A port appeared to be found by the IDE but, after uploading, the port disappeared. Can't seem to get pass this mess after several attempts and restarting the PC (Windows 11).

Interestingly, after double-reset and uploading the Basics example, the port number changed. Then I tried uploading my project code. The port disappeared. The upload process gave this output. I can find no indication of error.

> Sketch uses 37268 bytes (14%) of program storage space. Maximum is 262144 bytes.
> Global variables use 3924 bytes (11%) of dynamic memory, leaving 28844 bytes for local variables. Maximum is 32768 bytes.
> Atmel SMART device 0x10010005 found
> Device       : ATSAMD21G18A
> Chip ID      : 10010005
> Version      : v2.0 [Arduino:XYZ] Apr 30 2019 12:41:57
> Address      : 8192
> Pages        : 3968
> Page Size    : 64 bytes
> Total Size   : 248KB
> Planes       : 1
> Lock Regions : 16
> Locked       : none
> Security     : false
> Boot Flash   : true
> BOD          : true
> BOR          : true
> Arduino      : FAST_CHIP_ERASE
> Arduino      : FAST_MULTI_PAGE_WRITE
> Arduino      : CAN_CHECKSUM_MEMORY_BUFFER
> Erase flash
> done in 0.875 seconds
> 
> Write 37276 bytes to flash (583 pages)
> [==============================] 100% (583/583 pages)
> done in 0.298 seconds
> 
> Verify 37276 bytes of flash with checksum.
> Verify successful
> done in 0.036 seconds
> CPU reset.
> Board at COM11 is not available
5

Interesting.... Had been creating an instance of my library class using \

MessageHandler messagingLibrary(localAddress);

Changed it to:

MessageHandler *messagingLibrary = NULL;
...
messagingLibrary = new MessageHandler(localAddress);

The problem went away after that. But I do not know why.