3 Replies Latest reply on May 20, 2015 11:36 AM by DaKn_263916

    Floating I2C pins?


       Hi, I'm finishing up a prototype design using the PSoC4013.  I'm using the I2C pins for factory calibration with the MiniProg3 as an I2C bridge.  I read that the miniprog3 has the pullups, so they're not needed for communication.  I know its probably not advised, but will floating I2C pins cause any problems after leaving the factory, ie increased current draw, phantom communication etc?  Will executing a EZI2C_Stop() be enough to alleviate the problem?





        • 1. Re: Floating I2C pins?

          I looked at the EZ code for stop, its not clear to me whether GPIO


          is in fact put in a known state, and whgat state.




          You could do your own GPIO register writes to force the pin state,


          this ap note discusses how -








          http://www.cypress.com/?rID=93401     AN86439 - PSoC® 4 - Using GPIO Pins






          and restore the state prior to issue Ez_Start( ).




          However I still advise you file a CASE and ask if the above is necessary, if so what


          is the correct way to do this.




          One other possibility, add pullups on the board.




          Regards, Dana.








          To create a technical case at Cypress -








          “Technical Support”


          “Create a Case”




          You have to be registered on Cypress web site first.

          • 2. Re: Floating I2C pins?

             Hi Dana, Thanks for looking into this for me.  I thought about relaying out the PCB, but its a small board packed with parts already.  I thought the best option might be to disable the I2C pins after factory cal.  I'll submit a case and see what they say.







            • 3. Re: Floating I2C pins?

              Glad to have been of assistance.




              Regards, Dana.