8 Replies Latest reply on Jul 19, 2015 3:10 AM by user_14586677

    LM35 on PSOC4

    nainesh.doshi

      Dear All,

         

      Can i have any project on LM35 + PSOC4 ? for my reference. 

         

      As i am working on one project right now in which i have to interface PSOC4 with LM35 and based on temperature out from LM35 i have to send commands on UART to master controller.

         

      Naintech.

        • 1. Re: LM35 on PSOC4
          user_1377889

          You mainly need an UART and an ADC, for both of them are examples available (right click on the component).

             

          Putting both together will be the work you need to do, remember you need 5V supply, maybe you need a level shifter (MAX232 or eq.) for UART signals.

             

           

             

          Happy coding

             

          Bob

          • 2. Re: LM35 on PSOC4
            user_14586677

            On start page is a link to "Find Example Projects", in that is an example using

               

            A/D. Same for UART. You can draw on these to make up your project.

               

             

               

            RS232 levels - http://www.arcelect.com/rs232.htm

               

             

               

            Regards, Dana.

            • 3. Re: LM35 on PSOC4
              user_342122993

              naintech,

                 

              I suggest to use digital thermometer DS18B20 from MAXIM instead of analog TM35. It has same formfactor, but better absolute accuracy (0.1C v. 0.5C for TM35), and its output is already digitized. Example project and component can be downloaded here.

                 

              odissey1

              • 4. Re: LM35 on PSOC4
                user_14586677

                Looking at Maxim DS accuracy is -

                   

                   

                 

                   

                • 5. Re: LM35 on PSOC4
                  user_342122993
                          Dana, DS18B20 are factory trimmed and calibrated. From my experience, device-to-device reproducibility is within one bit, that is 0.065C. Also tested in boiling water and melting ice with about same absolute and relative accuracy. Again I am talking about DS18B20, not DS18S20. I don't see advantages using TM35. odissey1   
                  • 6. Re: LM35 on PSOC4
                    user_14586677

                    Here is the datasheet I found, +/- .5 C accuracy.

                       

                     

                       

                    LM35 $ .60 to $ 2.00, DS18B20 $ 2.00 to $ 4.00, Digikey

                       

                     

                       

                    Regards, Dana.

                    • 7. Re: LM35 on PSOC4
                      user_1377889

                      For a proof-of-concept or a functioning prototype the price might be negligible (depending on the re$our$es available). Of interest might be the time to program the system, but here PSoCs are fastes (as I experience).

                         

                      All this premises will change with the number of devices planned to be fabricated. A Sensor which needs an ADC to be red will always be cheaper than one which already has this part integrated together with a communication interface. Since a PSoC comes to us with the needed hardware inside (remarkable: at the price of the more complex sensor!!!) I (personally) would tend to choose the version which uses the cheaper and simpler sensor.

                         

                       

                         

                      Bob

                      • 8. Re: LM35 on PSOC4
                        user_14586677

                        A Sensor which needs an ADC to be red will always be cheaper than one which already has this part integrated together with a communication interface.

                           

                         

                           

                        That's wholly dependent on process geometry being used and marketing plans. End of life

                           

                        components, usually less integrated, older geometries, often carry higher prices. Price a 29466

                           

                        out vs the equivalent in a PSOC 3 / 5LP.....

                           

                         

                           

                        Regards, Dana.