I am running on rpi zero w using Adafruit-Blinka 6.4.0 and adafruit-circuitpython-lc709203f 2.0.2 and adafruit-circuitpython-bitbangio 1.2.4 on raspbian buster python 3.7.

I am trying to use bitbangio as I also have an SSD1306 on the normal H/W I2C ports (and it won't work with the clock stretching needed with the lc7).

If I run the lc7 on the H/W I2C ports with clock stretching set to 10KHz it mostly works (I do get occasional CRC errors). However when trying to use the bitbangio I always get the CRC error, no matter what frequency I set for it. (I tried everything from 10KHz down to 100Hz).

The only change to the simple test is using i2c from bitbangio. I have tried multiple GPIO pin combinations (D23,D24 and D20, D21).

LC709203F simple test
Make sure LiPoly battery is plugged into the board!
Traceback (most recent call last):
  File "test-batmon-bitbang.py", line 17, in <module>
    print("IC version:", hex(sensor.ic_version))
  File "/home/pi/.local/lib/python3.7/site-packages/adafruit_lc709203f.py", line 127, in ic_version
    return self._read_word(LC709203F_CMD_ICVERSION)
  File "/home/pi/.local/lib/python3.7/site-packages/adafruit_lc709203f.py", line 187, in _read_word
    raise RuntimeError("CRC failure on reading word")
RuntimeError: CRC failure on reading word

I have read that this CRC error is quite common on different platforms, and I wonder if there are any hints as to how to make this work.