I’m making my first attempt at I2C and need a little guidance. I’m using a Hydra with an Extender module on socket #3 (Y) that is connected to a Boarduino as follows…

SCL = Extender pin #6 is connected to Boarduino An5 (w/ 1K pull-up resistor)
SDL = Extender pin #7 is connected to Boarduino An4 (w/ 1K pull-up resistor)

I’m using the SoftwareI2C driver code from the WIKI on the Gadgeteer since I have to use a Y socket. So, hardware I2C isn’t an option.


I combined the Arduino Wire “slave_sender” and “slave_receiver” examples and am running that on the Boarduino. I’ve added LEDs so that if anything is received it blinks red, if anything is sent it blinks green.

I’m getting no responses from the Arduino.

First of all, has anyone done this before using the NETMF SoftwareI2C software and the Arduino Wire library? Any known issues I need to be aware of? Any better ideas on how to debug this? I have no scope…

One thing that’s not clear to me in the SoftwareI2C code is whether it is for being a master or is it slave only? I can’t find anywhere to designate which I2C address to send/receive data from. Am I missing something? On the Arduino side, it is setup as I2C address 4.

Any and all help appreciated.