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Cannot write to objects - Raspberry Pi 2 - C code

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  • Cannot write to objects - Raspberry Pi 2 - C code

    Hello All,

    I've got myself a Rasp Pi 2 and a uLCD-70DT but am having issues running my code or even the demo codes.
    I seem to be able to get the events from the LCD using my program or the monitor demo, but every time that I enable a write object to the LCD the program hangs and does not update.

    I've followed all the directions for installing the Libraries and I assume the connections are OK since I get events from it. I can work the display and set/read everything using GTX as well, but the C program cannot send/set any of the objects. Do you guys have insight for me?

    Thanks in advance ...

  • #2
    Just to say I'm having the exact same problem on a Raspi2. Trying to use calculator or demo-monitor, the programme hangs at the first WriteObj.
    Anyone got a direction on this?


    • #3
      Hi Guys

      Can you point me to the demo you are using, and the library you are using. I assume you are using the latest versions from Github?

      Just to be sure, please post the links.

      Raspberry Pi 2 has not been tested on these libraries, just so you know. These libraries have been out for some time, and were designed for the standard Pi B.

      We will have a look and see if its obvious what the problem might be, so please be patient.
      We have not stated it is compatible with the Pi 2.



      • #4
        Hi James,

        Thanks for taking the time to address this.
        I am using all the Github links from the product webpage:

        My Raspberry Pi 2 setup:
        [email protected] ~ $ uname -a
        Linux raspberrypi 3.18.7-v7+ #755 SMP PREEMPT Thu Feb 12 17:20:48 GMT 2015 armv7l GNU/Linux
        [email protected] ~ $ /opt/vc/bin/vcgencmd version
        Feb 14 2015 22:23:03
        Copyright (c) 2012 Broadcom
        version 7789db485409720b0e523a3d6b86b12ed56fd152 (clean) (release)

        I looked at the code for the library and I believe the issue is that the genieAck and genieNak never get set from reading the response of the write object. And because of this I am assuming that the message does not get sent to the LCD or is corrupted. The programs hang because there are never ending loops in geniePi.c but even implementing a timeout does not solve the issue:

        // TODO: Really ought to timeout here, but if the display doesn't
        // respond, then it's probably game over anyway.

        while ((genieAck == FALSE) && (genieNak == FALSE))
        delay (1) ;

        return 0 ;

        I would appreciate your prompt response.


        • #5

          I have put in the request for someone to look at it, however you will need to wait for that to happen.
          This might take a bit of time to sort out, but it will be looked at as soon as someone who knows about the Pi is available.