ESP32S2: cpu.reset_reason is wrong when resetting from button or microcontroller

[Neradoc]

The ESP32S2 gives POWER_ON as a reset reason when pressing the reset button (I expected RESET_PIN).
microcontroller.reset() gets a WATCHDOG reset reason (expected SOFTWARE).

Tested on MagTag (latest) and ttgo (beta 2), printing out microcontroller.cpu.reset_reason.

[anecdata]

Possibly related: #3858

[microdev1]

• The reset button is wired to S2's chip enable pin so it literally turns off the chip. That's the reason for POWER_ON status.
• I am getting the expected SOFTWARE as reset reason when using microcontroller.reset(). Can you try with current main.

[Neradoc]

Ah I was thinking something like that might be going on with the reset button. That's too bad.

I tried latest S3, and compiled current main on the Magtag.
Adafruit CircuitPython 6.2.0-beta.2-230-g64192b0eb on 2021-03-01; Adafruit MagTag with ESP32S2
I tried manually calling microcontroller.reset() in the REPL.
I also used this code on battery to exclude the possibility of USB messing with it.

I get WATCHDOG in both cases. (Well, except on first boot).

import board
import displayio
import microcontroller
import terminalio
import time
from adafruit_display_text import label

display = board.DISPLAY
splash = displayio.Group(max_size=10)
display.show(splash)

text = label.Label(
    terminalio.FONT,
    scale = 3,
    color = (255,255,255),
    x = display.width // 2,
    y = display.height // 2 - 10,
    max_glyphs = 50,
    anchor_point = (0.5, 0.5),
)
splash.append(text)
print(microcontroller.cpu.reset_reason)
text.text = str(microcontroller.cpu.reset_reason)[28:]
display.refresh()

for x in range(20):
    print(microcontroller.cpu.reset_reason)
    time.sleep(1)
microcontroller.reset() # <--- should result in the screen changing to SOFTWARE

[microdev1]

Still unable to replicate this. Tried both in REPL and code.py.

Adafruit CircuitPython 6.2.0-beta.2-230-g64192b0eb on 2021-03-02; microS2 with ESP32S2
>>> import microcontroller
>>> microcontroller.reset()
# <--- Reset --->
>>> microcontroller.cpu.reset_reason
microcontroller.ResetReason.SOFTWARE

[Neradoc]

@microdev1 do you use the UF2 bootloader ? It seems to be what makes the difference.
I get the same result as you when I rease_flash and install Circuitpython from the bin.

[microdev1]

It seems to be what makes the difference.

Yup! I get WATCHDOG with UF2 and the expected SOFTWARE with non-UF2 build.

[microdev1]

I just tested this with TinyUF2 0.5.0 and this seems to be fixed.

[dhalbert]

This should be fixed now with the latest TinyUF2. Update your TinyUF2 bootloader to at least 0.5.0, following the instructions here: https://learn.adafruit.com/adafruit-magtag/install-uf2-bootloader. Thanks @microdev1 for testing and @hathach for the TinyUF2 fix.