ConnectCore 9C and I2C BUS

We are trying to use the I2C BUS of the ConnectCore 9C dev board to connect a I2C multiplex chip (PCF8575 - 16 I/O expander). But we are only able to address the higher I/o ports (P8 to P15). We used the sample (I2C GPIO) provided by the dev kit as a reference and the necessary changes have been made according to the chip datasheet and specifications.
By the way, the on-board (dev kit) chip (PCA9554), a 8 ports I/O expander, works ok.

Someone managed to run the I2C BUS with a I2C device (chip) other than PCA9554 ?

We are using C# and the Digi BSP.


Marcos Fogaca


Have you found any solution?? Nearly, I have had to work with I2C bus and a DS1338 RTC chip and finally I found the solution.