Quote Originally Posted by ralfmayr View Post
Hello Al,
another question:
What are the three definitions:
1. DEFINE I2C_SLOW 1
2. DEFINE I2C_HOLD 1
3. DEFINE I2C_SCLOUT 1
do?
1. => Used with LO > 8MHz and 100kHz devices
2. => Time Delay during acknowledge?
3. => Open Collector / Bipolar Clock on SCL? Dont Understand this!

So: I use PCF8575C and MAX3611 (both 400kHz devices) but both only work
correct when DEFINE I2C_HOLD 1 and DEFINE I2C_SCLOUT 1 is done.

Can you help?

Regards,
Ralf
Hi Ralf,
I can answer part of #3:
Open collector means the PIC has 2 states LOW where it takes the pin to ground and an open state where the pin is high impedance, so to get a high state it must have a pull up resistor to supply the power. I do not know what bipolar clock means, have not read up on this yet.