Hello @Handcannon

yes, I see that too. It seems that the latest versions (2.3.5 and 2.3.6) have power to port A disabled. E.g. port A has no power.

Please find my example in the UIFlow2 Project Zone which manually turns on power to port A: M5Tab5_Enable_Ext5V_EnvIV_Test_UIFlow2.3.6

I created an issue on github for this issue.

Thanks
Felix

I tried recreating your M5Tab5 script for the Core 2 and got these results:
(I realise that the RGB Unit doesn't use I2C but for port A to work I think I need to set it up in the same way anyway.)
The code:

import os, sys, io
import M5
from M5 import *
import m5ui
import lvgl as lv
from unit import RGBUnit
from hardware import I2C
from hardware import Pin
import time



page0 = None
switch0 = None
i2c0 = None
rgb_0 = None


bytearrayone = None


def setup():
  global page0, switch0, i2c0, rgb_0, bytearrayone

  M5.begin()
  Widgets.setRotation(1)
  m5ui.init()
  page0 = m5ui.M5Page(bg_c=0xffffff)
  switch0 = m5ui.M5Switch(x=130, y=105, w=60, h=30, bg_c=0xe7e3e7, bg_c_checked=0x2196f3, circle_c=0xffffff, parent=page0)

  page0.screen_load()
  bytearrayone = bytearray(1)
  i2c0 = I2C(0, scl=Pin(33), sda=Pin(32), freq=100000)
  i2c0.readfrom_mem_into(0x43, 0x03, bytearrayone)
  # set PI4IO P2 (Ext5V enable) as output
  print(hex(myByteArr[0]))
  myByteArr[0] |= 0x04
  print(hex(myByteArr[0]))
  i2c0.writeto_mem(0x43, 0x03, bytearrayone)
  i2c0.readfrom_mem_into(0x43, 0x05, bytearrayone)
  # set PI4IO P2 (Ext5V enable) to high
  print(hex(myByteArr[0]))
  myByteArr[0] |= 0x04
  print(hex(myByteArr[0]))
  i2c0.writeto_mem(0x43, 0x05, bytearrayone)
  time.sleep(1)
  rgb_0 = RGBUnit((33, 32), 3)


def loop():
  global page0, switch0, i2c0, rgb_0, bytearrayone
  M5.update()
  rgb_0.set_brightness(100)
  if switch0.has_state(lv.STATE.CHECKED):
    rgb_0.set_color(0, 0x6600cc)
  else:
    rgb_0.set_color(0, 0x000000)


if __name__ == '__main__':
  try:
    setup()
    while True:
      loop()
  except (Exception, KeyboardInterrupt) as e:
    try:
      m5ui.deinit()
      from utility import print_error_msg
      print_error_msg(e)
    except ImportError:
      print("please update to latest firmware")

1st attempt:

E (725096) i2c: i2c driver install error
E (725128) i2c: i2c driver install error
E (725275) i2c: i2c driver install error
Traceback (most recent call last):
  File "<stdin>", line 49, in <module>
  File "<stdin>", line 25, in setup
OSError: [Errno 116] ETIMEDOUT

2nd attempt:

E (740623) i2c: i2c driver install error
E (740655) i2c: i2c driver install error

A fatal error occurred. The crash dump printed below may be used to help
determine what caused it. If you are not already running the most recent
version of MicroPython, consider upgrading. New versions often fix bugs.

To learn more about how to debug and/or report this crash visit the wiki
page at: https://github.com/micropython/micropython/wiki/ESP32-debugging

MPY version : v1.25.0-dirty on 2025-09-30
IDF version : v5.4.2-dirty
Machine     : M5STACK Core2 with ESP32(SPIRAM)

Guru Meditation Error: Core  1 panic'ed (LoadProhibited). Exception was unhandled.

Core  1 register dump:
PC      : 0x40166a09  PS      : 0x00060730  A0      : 0x800dc068  A1      : 0x3ffd92f0  
A2      : 0x00000000  A3      : 0x3f4329e7  A4      : 0x00000000  A5      : 0x00000000  
A6      : 0x00000001  A7      : 0x3ffd92f0  A8      : 0x00000074  A9      : 0x3ffc1090  
A10     : 0x00000000  A11     : 0x3ffd94b0  A12     : 0x00000000  A13     : 0x00000001  
A14     : 0x00000000  A15     : 0x00000004  SAR     : 0x00000020  EXCCAUSE: 0x0000001c  
EXCVADDR: 0x00000088  LBEG    : 0x400945b2  LEND    : 0x400945bd  LCOUNT  : 0x00000000  


Backtrace: 0x40166a06:0x3ffd92f0 0x400dc065:0x3ffd9330 0x400f5729:0x3ffd9350 0x400dc46d:0x3ffd9390 0x401ec3f5:0x3ffd93d0 0x401ec4bf:0x3ffd93f0 0x40087c62:0x3ffd9410 0x401e65a8:0x3ffd94b0 0x401ec3f5:0x3ffd9510 0x402161ac:0x3ffd9530 0x402161e9:0x3ffd9570 0x401ec3f5:0x3ffd9590 0x401ec479:0x3ffd95b0 0x402187a4:0x3ffd95e0 0x401ed36c:0x3ffd9660 0x4008739e:0x3ffd9680 0x401e65a8:0x3ffd9720 0x401ec3f5:0x3ffd9770 0x401ec4bf:0x3ffd9790 0x40087c62:0x3ffd97b0 0x401e65a8:0x3ffd9850 0x401ec3f5:0x3ffd9880 0x401ec40e:0x3ffd98a0 0x4021bbf6:0x3ffd98c0 0x4021beda:0x3ffd9950 0x401fde08:0x3ffd9990




ELF file SHA256: 1843f6d45

Rebooting...
ets Jul 29 2019 12:21:46

rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0030,len:4340
load:0x40078000,len:15972
load:0x40080400,len:4
ho 8 tail 4 room 4
load:0x40080404,len:3656
entry 0x400805c0

       _  __ _               
 _   _(_)/ _| | _____      __
| | | | | |_| |/ _ \ \ /\ / /
| |_| | |  _| | (_) \ V  V / 
 \__,_|_|_| |_|\___/ \_/\_/  V2.3.6-hotfix2

E (2840) i2c: i2c driver install error

M5Tab5 UIFlow v2.3.6-hotfix solves the no power on port A issue.

Thanks
Felix

yes, I see that too. It seems that the latest versions (2.3.5 and 2.3.6) have power to port A disabled. E.g. port A has no power.

Please find my example in the UIFlow2 Project Zone which manually turns on power to port A: M5Tab5_Enable_Ext5V_EnvIV_Test_UIFlow2.3.6

I created an issue on github for this issue.

Thanks
Felix