1 2 Previous Next 15 Replies Latest reply on Oct 27, 2015 3:32 AM by userc_41342

    Interfacing AD5933 on PSoC 1



      I try to interface a AD5933 Chip on my PSoC 1 Evaluation Board, using the I2CHW-Module.
      Now I want to read out the status register and display the value on my LCD.
      It seems that the High-Level API doesn´t work very good (or I make some misstakes), so I use the low level API to realize the communication shown in the datasheet (http://www.analog.com/media/en/technical-documentation/data-sheets/AD5933.pdf).

      But where is my misstake? It seems that the chip doesn´t send anything.
      Thank you for help!

        • 1. Re: Interfacing AD5933 on PSoC 1

           Edit: There are no start conditions in my C-File. I have fixed that, this project is an old version.

          • 2. Re: Interfacing AD5933 on PSoC 1

            And does your program run now as expected?


            In the datasheet the I2C-address of AD5933 is shown as 0x0D (and not  0x06)








            PS: Where in Germany are you located? I live near Bremen.

            • 3. Re: Interfacing AD5933 on PSoC 1

              Hello Bob,


              thank you for your answer.
              Have some missunderstanding i by reading the datasheet...
              Thought the Address is 6 Bit + RW and not 7 Bit + RW. It looks little bit strange in the datasheet, because they only shown 6 Bit + RW in the Timing Diagram....just my oppinion


              I´m from Monheim, between Cologne and Dusseldorf.


              Thank you for an answer :)

              • 4. Re: Interfacing AD5933 on PSoC 1

                I´ve got the communication running.
                Now I try to generate a 30kHz Sine, like in the datasheet. The Display show the right register values, but my scope doesn´t messure a sine wave.
                If I understand the datasheet right, I have to write 0x10 to the high byte of the control register and fill the Frequencyregister with the frequency value (0x82 - 0x84).

                • 5. Re: Interfacing AD5933 on PSoC 1

                  I should think Analog Devices has example C code to run the part ? That


                  you could port to PSOC ?




                  The flow code chart in datasheet you have followed ?




                  Regards, Dana.

                  • 6. Re: Interfacing AD5933 on PSoC 1

                    Ok now it works.
                    Do a simple measurement error....I connect my scope with the input and output of the voltage from the chip.
                    The scope impedance was too high. I use a 100k resistor now and now my scope measure the 2Vss sine wave.

                    • 7. Re: Interfacing AD5933 on PSoC 1

                      Congratulations! The datasheets for I2C slaves are difficult to read very often. There are different ways to specify the address and only some documentators rely on an automatically inserted/appended R/W-bit as the Cypress components do.






                      PS: Ausbildung in Leverkusen, Studium in Jülich. I know that Monheim area...

                      • 8. Re: Interfacing AD5933 on PSoC 1

                        Here is a project just using PSOC to measure Z (PSOC 3 based) -




















                        Regards, Dana.

                        • 9. Re: Interfacing AD5933 on PSoC 1

                          OK next job is to start the sweep. I programm the diagramm from the datasheet, but the sweep doesn´t start.
                          I like this datasheet from analog. Only missunderstanding comes from the timing diagramm. But they explain all other very good. 
                          Doesn´t read the datasheet very carefully, so I´ve got some problems :)




                          I´m on my way to finish my bachelor of engineering. Have done my education in Monheim :)

                          • 10. Re: Interfacing AD5933 on PSoC 1

                            Hello Kampi,


                            I am also using AD5933 for impedance measurement, but I am using PSoC 5PL. Nevertheless I have some issues. I managed to measure the temperature with the AD5933 but currently I have no idea if I am right with my code.


                            #include <project.h>
                            #include "stdio.h"


                            //asm(".global _sacnf_float");
                            #define TRANSMIT_BUFFER_SIZE  80
                            #define BUFFER_SIZE (0x02u)
                            #define SLAVE_ADDR_SIZE         (0x01u)


                            char TransmitBuffer[TRANSMIT_BUFFER_SIZE];
                            uint8   startfreq1[2]={0x82,0x0F}; //0x82=register address, second parameter are the first two hex-code letters of the start frequency
                            uint8   startfreq2[2]={0x83,0x5C};
                            uint8   startfreq3[2]={0x84,0x28};
                            //three arrays for the start frequency: 0x0F5C28


                            int main()
                                CyGlobalIntEnable; /* Enable global interrupts. */


                                UART_1_PutString("\n Starting...");
                                I2C_Start(); //I2C initialisation


                                I2C_MasterWriteBuf(0x0Du, (uint8*) startfreq1, BUFFER_SIZE, I2C_MODE_COMPLETE_XFER); //0x0Du=slave adress
                                //(uint8*) buffer, I2C_MODE_COMPLETE_XFER=performing a complete transfer from start to stop
                                I2C_MasterWriteBuf(0x0Du, (uint8*) startfreq2, BUFFER_SIZE, I2C_MODE_COMPLETE_XFER);
                                I2C_MasterWriteBuf(0x0Du, (uint8*) startfreq3, BUFFER_SIZE, I2C_MODE_COMPLETE_XFER);
                                if(!(I2C_MasterStatus() & I2C_MSTAT_XFER_INP))
                                sprintf(TransmitBuffer,"Command1: %d,%d ",startfreq1[0],startfreq1[1]);
                                UART_1_PutString(" Finished\n");
                                    /* Place your application code here. */


                            Maybe you could help me out with your AD5933 experience. But I am also grateful for every other help.


                            Thanks in advance,



                            • 11. Re: Interfacing AD5933 on PSoC 1

                              Please do not provide us with code snippets, they are too difficult to check when there is no help from the IDE. Better is always to upload a complete archive. What I see at first sight is: You are sending


                                if(!(I2C_MasterStatus() & I2C_MSTAT_XFER_INP))
                              That code will probably never get executed. What are your delays good for? required by datasheet? Can't you write all three frequency values at once? Isn't there in your device something like a write-pointer?





                              • 12. Re: Interfacing AD5933 on PSoC 1

                                The code


                                if(!(I2C_MasterStatus() & I2C_MSTAT_XFER_INP))


                                is working. I used it for the temperature measurement which was fully working. It is just to make sure that there is no more data transfer in progress.
                                The delays were somehow necessary, without them the temp measurement with the AD5933 didnt work.

                                And now I tried to use my knowledge an my working could for the impedance measurenment.


                                It is written in the datasheet to split up the frequency hex-code and send the pieces to different adresses. I used the "I2C_MasterWriteBuf" like in my project before. There it worked.


                                PS: What do you exactly mean by uploading a whole archive? In which form should i upload my code?

                                • 13. Re: Interfacing AD5933 on PSoC 1

                                  Uploading an archive:


                                  in Creator -> File -> Create Workspace Bundle(minimal)


                                  in Designer -> File -> Archive Project...


                                  then "Add Attachments" here in the forum with the resulting file.





                                  • 14. Re: Interfacing AD5933 on PSoC 1

                                    Datashett page 28 shows detailled how to access your chip via I2C. Differs a bit from your approach. Have a look at the block-read and -write functions and the mentioned data pointer!





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