1 2 Previous Next 24 Replies Latest reply on Apr 1, 2017 7:02 AM by fnoop Go to original post
      • 15. Re: related to uart 1
        Intel Corporation
        This message was posted on behalf of Intel Corporation

        Hello Umesh@pro3,

        I was wondering if you had the chance to check the previous message.

        An image of your setup may help us find the reason why you are experiencing the issue.

        If you have any other question or update, don’t hesitate to contact us.

        Regards,
        Andres V.

        • 16. Re: related to uart 1
          lamping.ap

          Andres,

           

          I've been digging through all of the information I can find on this forum and elsewhere to try to get UART 1 - /dev/ttyS1 to work. The information available is very inconsistent and unclear. Can you please provide more verbose details of how you set this up?

           

          I've seen replies that say UART needs to be configured in the BIOS. What does that mean? Is this necessary for using pins 22/24 - UART 1? I did see that the BIOS has a UART configuration parameter providing two options: Internal and SuperIO. What do these options mean?

           

          Also, I cannot find the specification for compatible baud rates. Do you have this information?

           

          I've tried using `screen /dev/ttyS1` to open the port and listen to the traffic. The port fails to open and screen terminates.

           

          I've tried using `x = mraa.Uart("/dev/ttyS1")` in Python with the library here -> GitHub - intel-iot-devkit/mraa: Linux Library for low speed IO Communication in C with bindings for C++, Python, Node.js… and I have the same issue as above. The command results in the constructor throwing  the "Error initialising UART" error.

           

          Some references I've thoroughly reviewed:

          Connecting to the Joule over UART through GPIO

          Uart(0) and Uart(1), etc. are meaningless on Joule... · Issue #612 · intel-iot-devkit/mraa · GitHub

          The Intel® Joule™ Compute Module | Intel® Software

           

          My system:

          Ubuntu 16.04

          mraa 1.5.1

          Joule BIOS GTPP161A.X64.0143.B30.1611152208

           

          Thanks,

          Anthony

          • 17. Re: related to uart 1
            Intel Corporation
            This message was posted on behalf of Intel Corporation

            Hello Anthony,

             

            I understand that there has been certain confusion regarding this topic.

             

            In this post I provide an explanation on how I was able to use UART 1 without configuring the BIOS. I’ll post it here again for convenience:

             

            I tried the following test:
            Using UART1, which is exposed on J12-22 and J12-24, I connected an external FTDI cable and opened a serial connection with a baud rate of 9600 (I used a PuTTY console).

            Executing the following command I was able to see the message displayed on the serial connection (a second PuTTY console):
            echo “hello” > /dev/ttyS1

            So, instead of opening a cmd window, I used two PuTTy consoles, with one I send information via USB communication, and with the other, through UART communication, I visualize the information.

             

            The corresponding team is aware of the confusion in the documentation and has already taken note of the information that you request, and I assure that we are working on the adequate documentation.

             

            Sorry for the inconvenience this may cause.

             

            Regards,
            Andres V.

            • 18. Re: related to uart 1
              lamping.ap

              Andres,

               

              That is not helpful. I asked for more verbose details. For example, you could reply with any pertinent BIOS settings or system configuration details (BIOS version, Linux kernel version, etc.).

               

              I don't see answers to my questions. I'll paste them here for further review:

              I did see that the BIOS has a UART configuration parameter providing two options: Internal and SuperIO. What do these options mean?

               

              Also, I cannot find the specification for compatible baud rates. Do you have this information?

               

              Thanks,

              Anthony

              • 19. Re: related to uart 1
                Intel Corporation
                This message was posted on behalf of Intel Corporation

                Hello Anthony, 

                I’ll be needing more time to investigate if that information is available.

                If I find information that you may find useful, I’ll post it here.

                Thank you for your patience.

                Regards,
                Andres V.

                • 20. Re: related to uart 1
                  lamping.ap

                  I found help elsewhere. You need the special kernel for the Joule and it works fine at 921600 baud. Bummer it is not released to the public yet though -> 16.04 - Where is the source for the 4.4.0-1000-joule kernel? - Ask Ubuntu 

                   

                  Anthony

                  • 21. Re: related to uart 1
                    Intel Corporation
                    This message was posted on behalf of Intel Corporation

                    Hello Anthony,

                    I want to share some results of a test that we did, and that may help you with the issue you are experiencing.

                    We were able to listen to traffic on both UART0 and UART1 using the pin mapping provided in the MRAA documentation https://iotdk.intel.com/docs/master/mraa/grossetete.html

                    You can use the sample code found here https://github.com/intel-iot-devkit/mraa/blob/master/examples/javascript/uart.js to check the functionality of UART (or any other language of your preference). 

                    To interact with the UART interfaces, we declared the new devices as you cited before:
                    u = new m.Uart('/dev/ttyS0'); or u = new m.Uart('/dev/ttyS1');

                    Here are the connections we followed using a regular FTDI cable:

                    /dev/ttyS0
                    UART0_TX - GPIO7 - ORANGE
                    UART0_RX - GPIO68 - YELLOW
                    UART0_RTS - GPIO70 - GREEN (NC)
                    UART0_CTS - GPIO72 - BROWN (NC)
                    UART0_GND - GPIO41 - BLACK

                    /dev/ttyS1
                    UART1_TX - GPIO22 - ORANGE
                    UART1_RX - GPIO24 - YELLOW
                    UART1_RTS - GPIO24 - GREEN (NC)
                    UART1_CTS - GPIO24 - BROWN (NC)
                    UART1_GND - GPIO41 - BLACK

                    Regarding your previous comment I've tried using `screen /dev/ttyS1` to open the port and listen to the traffic. The port fails to open and screen terminates, we noticed you are are missing the baud rate at the end of the command, also the device name is /dev/ttyUSB0 not /dev/ttyS1 (with Ubuntu 16.04). 

                    So the command would be as follows: 'sudo screen /dev/ttyUSB0 <baud rate>'.

                    These are the details of our setup:
                    Ubuntu 16.04
                    BIOS ID = GTPP183A.X64.0143.B30.1702012230
                    Linux intel-corei7-64 4.4.32-yocto-standard #1 SMP PREEMPT Thu Nov 17 15:03:26 UTC 2016 x86_64 GNU/Linux
                    MRAA Version: v1.5.1

                    As far as the list of baud rates, we did a quick test run using the most common baud rates (list below) and these work as expected.
                    1200, 2400, 4800, 19200, 38400, 57600, and 115200.

                    I hope you find the previous information useful.

                    Regards,
                    Andres V.

                    • 22. Re: related to uart 1
                      lamping.ap

                      Interesting... You are using the yocto kernel. That does not ship w/ standard Ubuntu. Which variation of the operating system are you using?

                       

                      I'm aware that screen needs a buad argument. I was just showing that multiple tools to use the port failed. Also, sudo shouldn't be required as long you are part of the dialout group.

                       

                      Canonical has a variation of Ubuntu 16.04 Desktop that comes with a kernel for the joule - Intel Joule | Developer. Which I installed and got working using /dev/ttyS1. What is real dirty about this is that they are not sharing the kernel as required by GPL. Some asked for it (link in my previous comment) and they said they were waiting on Intel for something.

                       

                      They have since removed their comments - even more dirty - and put the question on hold... here is what it used to say (thanks to Google caching):

                      Screenshot from 2017-03-31 14-09-45.png

                      Here is what it says now:

                      Screenshot from 2017-03-31 14-17-49.png

                      • 23. Re: related to uart 1
                        Intel Corporation
                        This message was posted on behalf of Intel Corporation

                        Hello Anthony, 

                        I’m sorry to inform you that Ubuntu and Ubuntu Core are out of the scope of this technical support team. Ref-OS-IoT (a new distribution of Linux OS) that is based on the linux-yocto-4.4 kernel, and that also uses the Yocto Project tools (https://software.intel.com/en-us/intel-joule-getting-started) is the supported OS.

                        In order to receive the adequate assistance, please get in touch with the corresponding support team: https://developer.ubuntu.com/core/troubleshooting

                        Sorry for the inconvenience this may cause.

                        Regards,
                        Andres V.

                        • 24. Re: related to uart 1
                          fnoop

                          Wow, the whole question has been deleted now, apparently in response to my comments asking if this was in violation of the GPL (which it clearly is)

                          ubuntu-joule-deleted.jpg

                           

                          That's absolutely disgraceful.

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