8 Replies Latest reply on Jan 29, 2015 3:04 PM by user_285675076

    oneWire and CY8C21345

    user_285675076

      Hello,

         

        I am working on a small project, that requires the reading and display of a DS18B20 sensor. I searched for a small chip, and I bought the CY8C21345. However, when I started working with it, I foud out that there is no OneWire component in the components list. Is there any bit banging program for this protocol that can be implemented with the M8C (I have it working on PSoC 3, but not for PSoC 1)? From what I have seen, the smallest delay you can get here is 50u. Can you generate the code from the component found on ther PSoC 1 chip?

         

      Thank you!

        • 1. Re: oneWire and CY8C21345
          arvi

          Hello,

             

           

             

          The Onewire usermodule should be there! As per the v1.1 datasheet Onewire is supported in the following PSoC1 devices -

             

          CY8C29/27/24/23/21xxx, CY8CLED02/04/08/16, CY8CLED0xD, CY8CLED0xG, CY8C28x45, CY8CPLC20, CY8CLED16P01, CY8C28xxx. We'll check on this and fix it in the next update PSoC Designer.

             

           

             

          Regards,

             

          Arvind

          • 2. Re: oneWire and CY8C21345
            user_14586677

            Frtom datasheet shows support for 21xxx -

               

             

               

            OneWire Datasheet OneWire V 1.1

               
                
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        

            Resources

            PSoC® Blocks

            API Memory (Bytes)

            Pins (per External I/O)

            Digital

            Analog CT

            Analog SC

            Flash

            RAM

            CY8C29/27/24/23/21xxx, CY8CLED02/04/08/16, CY8CLED0xD, CY8CLED0xG, CY8C28x45, CY8CPLC20, CY8CLED16P01, CY8C28xxx

            Main UM

            2

            0

            0

            168

            1

            2

            + Optional CRC16

            0

            0

            0

            43

            2

            0

            + Optional Search

            0

            0

            0

            618

            11

            0

            + Optional Overdrive Speed

            0

            0

            0

            45

            1

            0

            + Optional Parasite Power

            0

            0

            0

            42

            1

            0

                
               
               
                          

            Features and Overview

               
            • 3. Re: oneWire and CY8C21345
              user_285675076

              Here is a screenshot of my project's layout. I cannot find OneWire there.

                 

              Thanks!

              • 4. Re: oneWire and CY8C21345
                user_14586677

                Why dont you file a CASE on this, seems like it may be an

                   

                error. Might be able to import the module into design, ask

                   

                if thats possible. Use a link to your post.

                   

                 

                   

                    

                   

                          

                   

                To create a technical or issue case at Cypress -

                   

                 

                   

                www.cypress.com

                   

                “Support”

                   

                “Technical Support”

                   

                “Create a Case”

                   

                 

                   

                You have to be registered on Cypress web site first.

                   

                 

                   

                Regards, Dana.

                • 5. Re: oneWire and CY8C21345
                  arvi

                   Hi,

                     

                   

                     

                  Apologies for the previous, it looks like the OneWire v1.1 datasheet is not accurate..

                     

                   

                     

                  Instead of   CY8C21xxx, it should read CY8C21x34, this is the only device currently suported in that series.

                  • 6. Re: oneWire and CY8C21345
                    user_285675076

                    Thank you for your replies. Do you know, is there any bit banging solution for one wire in PSoC 1?

                    • 7. Re: oneWire and CY8C21345
                      user_14586677

                      Take a look at this, and references at bottom for solutions -

                         

                       

                         

                          

                         

                                http://en.wikipedia.org/wiki/1-Wire

                         

                       

                         

                      Regards, Dana.

                      • 8. Re: oneWire and CY8C21345
                        user_285675076

                        Thank you! It works.