3 Replies Latest reply on Jun 25, 2018 11:42 PM by rajiv.vasanth.badiger

    PSOC 4 thermistor interface

    rajakumar.r_2227736

      Hi I want to interface thermistor with PSOC4 . so i am using cypress example program.

      i am using 10k thermistor . while using this example project i am getting some random outputs. kindly help me to resolve this. i have attached the thermistor data sheet and program.

       

       

      thermistor part number:B57540G1103H000.

      psoc kit used :CY8CKIT-042

       

       

      thanks and regards

      Rajakumar

        • 1. Re: PSOC 4 thermistor interface
          e.pratt_1639216

          Well, you are polling for the ADC to finish, I don't believe you need to call ADC_StopConvert(); afterwards, as it only returns if it completed the ADC conversion. That might be why it is causing randoms values to spit out?

           

          Just as an FYI, Modulus operations (% symbol) are very slow in programs, so if you want better performance/speeds, trying not to use it is preferable.

           

          Try debugging the program with the SWD ports, and see what values the RAM are showing for iTemp, iRes, and how the filtering.

          • 2. Re: PSOC 4 thermistor interface
            user_13463998

            Dear Rajakumar-san,

             

            Since I could not figure out your top circuit, I'll put my temp test project (for CY8CKIT-044).

            May be you need to recreate the project for -042.

             

            My top circuit is

            TempSense.JPG

            And as "B" parameter of my therm is different from yours,

            please modify line 24 of main.c from

            #define B 3435

            to

            #define B 3492

             

            And as I'm using log(), we need to add command line "-lm" in Build Settings Compiler and Linker

            Compiler_command_line.JPG

            Linker_Command_line.JPG

             

            Hope this can be a bit of hint/help.

             

            Best Regards,

            26-Jun-2018

            moto

            • 3. Re: PSOC 4 thermistor interface
              rajiv.vasanth.badiger

              Rajakumar,

               

              Your project seems to be working fine. Can you please check the following?

              1. See if the bias voltage is applied

              2. Check the connection from P4[1] on header J3 to PSoC 5LP's P12[6] on header J8 for UART

               

              Also, please check if you can make a change in firmware as suggested by other members.

               

              -Rajiv