1 2 Previous Next 22 Replies Latest reply on May 20, 2014 4:04 AM by ctm.ctm

    UART example

    nivedhitha.selvakumaran

       i have a link here that is an example of UART. 

         

      http://www.cypress.com/?docID=35078

         

      what is the VR pin of j5? to it we are connecting the p0.1 analog input pin. why? Is it directly connected to the UART?

        • 1. Re: UART example
          user_14586677

          P0[1] is the A/D input, and is conencted to the pot (R7) wiper on J7,

             

          pin 4. Thats to allow varying the pot and transmitting the A/D result of

             

          the pot wiper voltage via the UART.

             

           

             

          UART is just connected to P2[5] and P2[7]

             

           

             

          Regards, Dana.

             

           

             

           

          • 2. Re: UART example
            junichi.hiraoka

            Hi Nivi,
            Your question is seems difficult to answer but.
            Have you learn about Electronics, Signal processing?
                  

                          

               

            Every signal need to handle step by step.
            For this example, There are signal and modules,
            Each module has each role.      

             

               

              

               

            A signal is the voltage of that get from VR.
            First step is PGA due to amplify the signal.      

             

               

                

                      

               

            Next is ADC, DelSig that convert analog voltage into digital value.
            The digital value(it mean voltage of VR) can transfer by UART to the PC, etc.      

             

               

              

               

            The analog value(VR voltage) can't transfer by UART directly,
            This is a reason of your question why.      

             

               

            Are you able to get something from this?
             

               

            Best way to understand that is
            To be work with this example, and Measure signal step by step,
            And finally accept signal by the PC.      

             

               

                

                      

               

            That is I guess. Feel free ask again.      

             

            • 3. Re: UART example
              nivedhitha.selvakumaran

               @PSoC73: I apologize for not responding sooner. I had not realised that it was just an instruction pertaining to hardware connections at that time. Thank you anyway for replying.

              • 4. Re: UART example
                ctm.ctm

                Hi every body! Help me!!!

                   

                I have a prolem when PSoC conect to PC via RS232 circuit (UART).

                   

                I need:

                   

                - PSoC recieve data from PC send (char,string...).

                   

                - If PSoC receive character 'a', turn on led; else turn off led.

                   

                Pin:

                   

                P0.4: RX

                   

                P0.5: TX

                   

                P0.3: led

                   

                Currently, hardware is fine. But code not work as i need!

                   

                I checked configuration PSoC, code of my project.

                   

                I upload my project for every body.

                   

                Can you help me, please?

                   

                I do this project because i will do project: 

                   

                -P0.4 receive data (char, string...) from pC.

                   

                -P0.5 forward data that P0.4 received to PC.

                • 5. Re: UART example
                  ctm.ctm

                   Sorry! My project here.

                  • 8. Re: UART example
                    user_14586677

                    Just a check, you have a RS232 transceiver connected to your PSOC

                       

                    to develop RS232 levels for the PC serial interface ?

                       

                     

                       

                    Also I see you are driving LED by setting port to high, implying LED wired from Vss to

                       

                    a series R to pin. The pin cannot source as much current as sink, better you connect LED

                       

                    to Vdd to series R to port, and turn it on driving pin to "0", Vss.

                       

                     

                       

                    Regards, Dana.

                    • 9. Re: UART example
                      ctm.ctm

                       Hi you,

                         

                      About RS232 circuit which i used: it is good because i coded a example to test.

                         

                      - TX on PSoC transmit data (char, string) to PC, PC received data and show well.

                         

                      - But RX on PSoC can't work. 

                         

                      (I'm using software: Terminal 1.9b to check communication between PSoC and PC)

                         

                      I use 1 led to test, not more. I think project has no prolems with that led.

                         

                      Can you check about configuration of my project, please?

                         

                      Or, Is code incorrect?

                         

                      I have just studied PSoC!

                         

                      Many thanks!

                         

                       

                      • 10. Re: UART example
                        user_1377889

                        Just to check: Are you using a voltage-level shifter between PC-Tx and PSoC-Rx lines or are you trying to fry the PSoC with +-12V ?

                           

                         

                           

                        Bob

                        • 11. Re: UART example
                          ctm.ctm

                          Hi Bob,

                             

                          I'm using a voltage-level shifter between PC-Tx and PSoC-Rx lines by IC MAX232.

                             

                          Details:

                             

                          PC  <->USB to COM <->RS232 circuit (using MAX232)<->PSoC CY8C24123A.

                             

                          (Pin:

                             

                          - P0.4 (RX of PSoC) connect pin 12 max232.

                             

                          - P0.5 (TX of PSoC) connect pin 11 max232.

                             

                          )

                          • 12. Re: UART example
                            user_1377889

                            It is not a good idea to have the LED on the same port as the UART when you are writing to the data register!!!

                               

                            Better use an LED-component which will use a shgadow-register internally.

                               

                             

                               

                            Bob

                            • 13. Re: UART example
                              ctm.ctm

                               Hi Bob,

                                 

                              I will try connect led to another pin (not in PORT0), conect to PORT1 (P1.1 or P1.0, because I'm using PSoC CY8C24123A).

                                 

                              Can you send a project(communication between PSoC1 and PC, UART) for me if you had, please?

                                 

                              Contents:

                                 

                              -PSoC RX receive data (char, string...) from pC.

                                 

                              -PSoC TX forward data which P0.4 received to PC.

                                 

                              Many thanks for your help!

                              • 14. Re: UART example
                                user_14586677

                                On the opening page of PSOC designer is a link, ~ 1/2 way down page, "Launch

                                   

                                Example Browser", and there are several UART projects you can try out/modify.

                                   

                                 

                                   

                                Regards, Dana.

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