Relationship of Mini Breakout to SCL/SDA

[CCarl5]

I am looking to hook up a motor controller (MD22) to the Edison mini breakout using i2c. I have already setup & tested a logic shifter for the signal, etc. I am stuck on how to decide which i2c pins would be used for he SDA input and the SCL input. From the i2c spec the SCL is the clock, and the SDA is 1bit. How do I choose the correct pins? I will be using C & mraa so that will likely be my next question...

Thanks!

[Carlos_M_Intel · Accepted solution]

Hi Carlos,

I suggest you to take a look at the Hardware Guides of the http://download.intel.com/support/edison/sb/edisonbreakout_hg_331190006.pdf Breakout Boardhttp://download.intel.com/support/edison/sb/edisonbreakout_hg_331190006.pdf and the http://download.intel.com/support/edison/sb/edisonmodule_hg_331189004.pdf Edison Compute Modulehttp://download.intel.com/support/edison/sb/edisonmodule_hg_331189004.pdf .

On the breakout boar you will need to use the I2C6 interface:

J17 - pin 7 -> SCL

J17 - pin 9 -> SDA

About C & MRAA, take a look at the following links:

Examples: https://github.com/intel-iot-devkit/mraa/tree/master/examples mraa/examples at master · intel-iot-devkit/mraa · GitHub

MRAA Documentation: http://iotdk.intel.com/docs/master/mraa/ mraa: Main Page

Regards,

Charlie

[CCarl5]

Thank you as always. I knew I had seen this weeks ago when reviewing the docs, but lost track of it.

Just a minor detail - this would actually be J17 Pin 8 and J18 Pin 6, as pairs right?

[Carlos_M_Intel]

Hi Carlos,

No, the Edison Module has 2 interfaces for I2C, I2C1 and I2C6.

J17 - pin 7 and J17 - pin 9 are the GP27 and GP28 you can use these for General purpose. The interface located in GP19 and GP20 in J18 - pin 6 and J17 - pin 8 is the interface connected to the MCU.

Regards,

Charlie

[CCarl5]

Thank you for clearing that up! Maybe a dumb question but - if I end up adding additional i2c devices in the future, they all share the pins - but only the addresses change, correct?

[Carlos_M_Intel]

Hi Carlos,

Yes, that is correct, you can use different devices connected to the SCL and SDA pins. The Address will be the flag that will let them know when and what to do.

Regards,

Charlie