I2C api. SCL and SDA rising edges are sawtooth, not square waveforms; logic 1 voltage is only 2.5V (not 3.3V)

[timyu1477]

Hi All, I set up a simple I2C interface with ftdi://ftdi:232h:FT0J4XG6/1 (C232HM-DDHSL-0). Two problems

1. The rising edges of the SCL and SDA are sawtooth, not square waveform. It seems not be in drive-zero...
2. The logic 1 voltage is pulled down as about 2.5v (probably related with the in pyfdti/pyftdi.py Ftdi.BUS_CLOCK_MAX is not defined #1. )
   Can someone point out some issue in the configuration?
   Code as following:

from pyftdi.ftdi import Ftdi
from pyftdi import i2c
ctrl = i2c.I2cController() # instantiate FTDI as controller
ctrl.configure('ftdi://ftdi:232h/1') # use standard setup, 3-phase-clocking, drive0, 100KHz etc.

The DUT address i0x38

poll_status=ctrl.poll(0x38,relax=True)

print(poll_status)

[eblot]

What values of the pull-up resistors do you use?

Have you try to execute this script w/o any slave and observed the waveforms?