@felmue Felix, thanks for your response.
This indeed works.
Trying to read/write some other registers (digital in) no luck yet, but at least there is some progress.
Thanks again.

@ggong Hello, did you manage to get it working?? I am pulling my hair out as all M5 products were working straight out of box.
My setup is Atom Lite running freshly built S3 variant of micropython. I am getting ETIMEDOUT each time. Example code:

from machine import SoftI2C, Pin
DEFAULT_ADDR = const(0x45)
FW_VERSION_REG = const(0xFE)
i2c =SoftI2C(scl=Pin(1), sda=Pin(2), freq=400000
print(i2c.readfrom_mem(DEFAULT_ADDR, FW_VERSION_REG, 1))

I'll appreciate any help.
DG