you're very welcome.

The required fix mentioned before has now been included to the M5Core2 library so hopefully in one of the next UIFlow updates it will be picked up.

Happy Stacking!
Felix

Thank you, I have tested your program and it works perfectly. Thank you very much for that !

THX skink

here is a Python solution. Button A decreases, Btn C increases intensity. Btn B turns vibration motor on and off:

from m5stack import *
from m5stack_ui import *
from uiflow import *
import i2c_bus

screen = M5Screen()
screen.clean_screen()
screen.set_screen_bg_color(0xFFFFFF)

label0 = M5Label('Text', x=52, y=67, color=0x000, font=FONT_MONT_24, parent=None)

from numbers import Number

motorOnOff = None
motorValue = None
temp = None

def setMotorValue():
  global motorOnOff, motorValue, temp
  label0.set_text(str(motorValue))
  temp = (i2c0.read_u8(0x28)) & 0xF0
  temp = temp | motorValue
  i2c0.write_mem_data(0x28, temp, i2c_bus.UINT8LE)

def buttonA_wasPressed():
  global motorOnOff, motorValue, temp
  if motorValue > 0:
    motorValue -= 1
  setMotorValue()
  pass
btnA.wasPressed(buttonA_wasPressed)

def buttonC_wasPressed():
  global motorOnOff, motorValue, temp
  if motorValue < 15:
    motorValue += 1
  setMotorValue()
  pass
btnC.wasPressed(buttonC_wasPressed)

def buttonB_wasPressed():
  global motorOnOff, motorValue, temp
  motorOnOff = not motorOnOff
  power.setVibrationEnable(motorOnOff)
  pass
btnB.wasPressed(buttonB_wasPressed)

i2c0 = i2c_bus.easyI2C(i2c_bus.PORTA, 0x34, freq=400000)
motorOnOff = False
motorValue = 7
setMotorValue()

Cheers
Felix

that is not very surprising. To set the vibration intensity an underlying function SetLDOVoltage() is used which currently is broken in M5Core2 library as pointed out by @veryalien :
https://github.com/m5stack/M5Core2/issues/4.

I've proposed a fix in a pull-request which got closed as it should be fixed in the near future anyways as @Hades2001 pointed out:
https://github.com/m5stack/M5Core2/pull/5

Cheers
Felix