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I'm using external RTC which has DS1307 where it communicates to my cc3200 using (SDA and SCL) I2C. Please note as oer block diagram there are two I2C interface available in cc3200 LP

I'm using RTC lib specified for ds1307 from here 

Option #1: when I connect my RTC module to Pin P01 and P02 (SCL and SDA) as detailed in CC3200 block diagram I see valid clock/time in my COM port 

Option #2: Now, When I try the with other I2C port in P4 40 and 39 (top two pins) I'm not seeing any clock/timer value 

Please help me to understand what might be the reason? why one I2C interface works while other does not? I'm not changing anything in my code/circuit 

I'm using Serial1 (which is also P01 and P02 similar to one of the I2c port interface) to communicate with other components.. thus we have only one choice to make use of P4 -40 and 39 ports to perform I2C... please help. 


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Hi @@gr8going


See the pin map and documentation here:  http://energia.nu/pin-maps/guide_cc3200launchpad/


The statement just above the pin map says...


The following diagram shows the complete pin map for the CC3200 LaunchPad in Energia. Note: the lighter colors indicate no connects. Click the image to view a larger version of the image.

Apparently pins 39 and 40 are not connected.


Edit:  See below....


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Hi FmilBurn,


Thanks for your reply...


From the Note: "...Note: the lighter colors indicate no connects..."


Does it mean in cc3200 LP we just have only one I2C ?? that is conflicting with UART1 (Serial1)  ??

is it possible for me to do multiplexing??


please help, both Serial communication and I2C interface are important for my project 



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Use pins 9 and 10.

This is what I did and working for I2C... and the same pin is what I'm using for Serial1 (UART communication) also so there is a conflict. 


Is it possible to do multiplexing between I2C and UART1 (serial1) which has same pin 9 and 10 ??

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BTW, I just referred this topic. Hope multiplexing is possible shall try and let you know..


All what I need to do is either

#1) Move the Serilal1 (UART1) to other GPIO pin (say 56, 57) and retain default I2C pin as 9 & 10.

#2) Move the I2C from 9 or 10 to some other GPIO and retain UART2 as is...


any other suggestions!!

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