[PIC] dspic30f4011 i2c 8 device connection suggestions

[raman00084]

hi every one i am planing to connect 6 i2c port expander mcp23017 (16bit port exp) , one ds3231 rtc , 24c512 eeprom . my doubt is can i connect 8 i2c devices in a singke scl and sda pin of dspic, the i2c speed is 400khz and pull up resistor is 2.2k , are i must use any buffer?

kindly help

my second doubt is mcp23017 i2c expander will work correctely without any flaw are bugs, all the 6 mcp23017 have different address and i am using 3 for input and another 3 for output. is i2c port expander reliable?

kindly give your valuable suggestions

 

[FvM]

Eight addresses available for mcp23017, so it should be fine. 8 Devices connected to I2C is pretty standard, I would use 1K pullup as a first attempt. There's a calculation provided in NXP I2C specification for different bus capacitance values.

 

[raman00084]

is i2c port expander reliable? it will work correctly like normal micro controller io without any problem?

 

[FvM]

It's reliable, but by nature considerably slower.