Strange behavior, Nano33 IoT

I am using the MAC version of the IDE, and today hooked up a Nano 33 for the first time. It came up, accepted downloaded code, and worked fine. At that point, it was being powered by the USB connection.

Then I powered it through the Vin pin, with 12 v., and the port connection went away. I could no longer communicate with the N33. I have never noticed a problem like that with any other Arduino board. Is there a reason, or a workaround, for that?

Thanks in advance for any suggestions.

jrdoner

Does communication start working again after you remove the 12 V connection?

Hi jrdoner,

I've had the same problem with my Nano IoT when I connected external power supply to Vin pin, in my cases the SAM21 chip was burned, it was wery hot.
Probably the MPM3610 step down converter could generated voltage spikes bigger then 3.3V when you connect external power supply. Some problem can be generated when NINA W102 module is supplying, because generate current spikes after start.

In my case I bought new IoT33 and I soldered 56uF capacitor close to NINA W102 module and transil diode 3.3V on the supply 3.3V line.