5 Replies Latest reply on Dec 26, 2016 11:40 AM by Intel Corporation

    RN2903 and Intel Edison Mini Breakout Board

    StevesTI

      Good afternoon,

       

       

      I made the Microchip RN2903 module connection on the Intel Edison Minibreakout Board UART port (/ dev / ttyMFD1) using a voltage converter once the module works on another voltage. I used several codes (UART template available intel XDK) to test using node language with the following modules: mraa and serialport. I am using the Intel XDK IDE and last tested code is as follows:

       

      var m = require('mraa'); //require mraa

      console.log('MRAA Version: ' + m.getVersion());

      u = new m.Uart(0)

       

       

      console.log("Note: connect Rx and Tx of UART with a wire before use");

       

       

      function sleep(delay) {

        delay += new Date().getTime();

        while (new Date() < delay) { }

      }

       

       

      console.log("Set UART parameters");

       

       

      u.setBaudRate(57600);

      u.setMode(8, 0, 1);

      u.setFlowcontrol(false, false);

      sleep(2000);

       

       

      console.log("First write-read circle:");

       

       

      u.writeStr("sys get ver\r\n");

      sleep(2000);

      console.log(u.readStr(20));

      sleep(200);

       

       

      console.log("Second write-read circle:");

       

       

      u.writeStr("sys get ver\r\n");

      sleep(2000);

      console.log(u.readStr(20));

       

       

      What happens is that there is no communication with the RN2903 module and the read function of the UART blocks the execution of the process or returns null value.

       

       

      The manufacturer indicates that it is necessary to always send CRLF at the end of the command and so I added \ r \ n.

       

       

      MRAA Version: 1.5.1

      Intel® Edison Module Firmware Software Release 3.5

       

       

      Thank you very much for the help.

        • 1. Re: RN2903 and Intel Edison Mini Breakout Board
          Intel Corporation
          This message was posted on behalf of Intel Corporation

          Hello StevesTI,

          Thanks for reaching out!

          First of all, I'd like to point out that Edison's UART bus also requires the new line and carriage return. So, you should also add those signals when communicating from the RN2903 to Edison.

          Now, addressing the main issue, do you have access to a logic analyzer? If so, could you please check the signals that are sent from the RN2903 to the level translator, to the Edison and vice versa? 

          It is important to verify that the signals are congruent, because if they are not, the issue might be found in the level translator and not on the RN2903 or the Edison. And in my experience, this is the most common issue when working at different voltage levels. The issue is mainly due to the switching rate, as the chip may not be fast enough to transfer the correct signals when translating them.

          So, this should be a good place to start. But, while doing so, make sure that what you are sending on your code is actually what is reflected on the signals.

          Let me know how it goes.
          -Peter.

          • 2. Re: RN2903 and Intel Edison Mini Breakout Board
            Intel Corporation
            This message was posted on behalf of Intel Corporation

            Hello StevesTI,

            Do you have any updates about this?

            -Peter.

            • 3. Re: RN2903 and Intel Edison Mini Breakout Board
              StevesTI

              Hi,

               

              I used a logic analyzer and verify that the ASCII LoRa RN2903 arrived perfectly, including the \r \ n.

               

              Comparing the UART communication between the USB - Serial converter and the one sent by Edison seems that Edison is a little bit quicker.

               

              I attached the logic analyzer screen and table for your review and insight.

               

              image.pngimage(2).pngimage(3).png

              • 4. Re: RN2903 and Intel Edison Mini Breakout Board
                Intel Corporation
                This message was posted on behalf of Intel Corporation

                Hello StevesTI,

                Thank you for sharing this information with us, it is of much help. However, I'm confused, I'm not sure what these readings represent. I mean, what does the first (and the second) picture represent? Is it the signal sent from the RN2903 to the level translator? Or, is it the signal from the level translator to the Edison? Or, is any of those but vice versa? 

                It would be really helpful if you could post a picture of every stage of the communication in order to be able to compare them.

                What you mentioned about Edison being quicker than the RN2903 confuses me. Is this because of the level translator? Or are they simply different?

                I noticed that you mentioned that the \r\n signals arrive correctly, but, is this both ways? Could you please confirm that you are also sending the new line and carriage return signals when communicating from the RN2903 to the Edison?

                I will be waiting for your response.
                -Peter.

                • 5. Re: RN2903 and Intel Edison Mini Breakout Board
                  Intel Corporation
                  This message was posted on behalf of Intel Corporation

                  Hello StevesTI,

                  Do you have any updates about this?

                  -Peter.