StamPLC Run Issue

lombric

Hello,

I wrote a small program containing only the initialization of a StamPLC module with its “StamPLC AC” power supply.

When I run “RUN,” the program list is sent to the module, and execution proceeds normally.

However, when I try to download the program, I get the following message:

MPY: soft reboot

   _  __ _

_ ()/ | | _____ __
| | | | | || |/ _ \ \ /\ / /
| || | | | | () \ V V /
_,||| ||___/ _/_/ V2.4.2

Traceback (most recent call last):
File "boot.py", line 44, in <module>
File "startup/init.py", line 1, in startup
OSError: (-4354, 'ESP_ERR_NVS_NOT_FOUND')
MicroPython v1.25.0-dirty on 2026-02-08; M5STACK StamPLC with ESP32-S3-FN8
Type "help()" for more information.

And the program does not run.

Could someone help me?

Thank you in advance for your response.

Swift_Solutions

@lombric I have also discovered this issue today, added the StamPLC AC module into my UiFloww V2.4.3 environment and it crashes the controller. I had to force reboot it and reflash it with M5 Burner to recover it. VERY frustrating as this is a hardware software combination all built by M5 Stack. I have no idea how to resolve this as your post is from Feb 2026 and there are zero responses...

Swift_Solutions

For anyone else who has a StamPLC and a StamPLC AC Relay and is having issues using the UIFLOW2 AC Relay Blockly module and getting errors. The below screenshot shows how to use the I2C module to get it working. I used the https://www.diodes.com/datasheet/download/PI4IOE5V6408.pdf datasheet to work out which registers need to be set up to get this working. Keep in mind the LED's work on an opposite logic level to the relay.

After Some Tinkering I have a working example for anyone else who needs it. UIFlow 2 Stamp PLC AC Relay Working Example Screenshot.jpg

I did try to share this on the project zone but like most things on here it throws errors instead of just working...