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Power Down Sequence Warning Explained

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  • #31

    Unfortunately I did not read these warnings before I started hacking around with my uOLED-96-G1 device when it arrived this week .. and now it appears that I have ruined it. Where once it powered up and gave me a static 'noisy' screen, now it powers up no more.

    Is it possible I've irreperably damaged this device by not observing the powerdown requirements? I'm distraught, as this was the perfect device for my small project (Arduino Mega + OLED + FAT drive + Old Oric Atmos = newschool disk drive For the Atmos computer) and it appears I must now order another one.

    Something I can do to determine the true damage caused by my ignorance?

    EDIT: Can someone point me in the direction of the warning text, as I have looked all over for it and cannot find it anywhere ..
    ibi sum


    • #32
      Here is a bit of code I use in all my programs to add a 'screen saver' feature which will also allow you to safely power off the module when the screen has turned off:

       #platform "uOLED-32028-P1T" 
      * Filename: Screen_Saver.4dg
      * Created: 19/02/2010
      * Author: Pro AV
      * Description: A demo of the screen saver to be included in most projects
      #constant SCREEN_TIMEOUT 10000 //Screen timeout in milliseconds
      /*MAIN CODE------------------------------------*/
      func main()
      var n, last_AD, current_AD, img_list, AGC;
      //Set initial operating paramaters
      //Random text to display for the screen saver demo
      txt_Set(TEXT_COLOUR, 0xFFFF); //White
      txt_Set(FONT_SIZE, FONT4); //FONT4 is default any way
      txt_Set(TEXT_OPACITY, OPAQUE); //Opaque text will overwrite previous text
      txt_Set(TEXT_HEIGHT, 1); //Normal height
      txt_Set(TEXT_WIDTH, 1); //Normal width
      print("This is a demo of\nthe screen saver.\n\nIt will turn off in\n");
      sys_SetTimer(TIMER0, SCREEN_TIMEOUT); //Set the screen timeout timer
      repeat //main code to be looped goes here
      txt_MoveCursor(4, 0);
      print(1+sys_GetTimer(TIMER0)/1000, " ");
      if(sys_GetTimer(TIMER0) == 0) //if we have reached the screen timeout
      gfx_Set(CONTRAST, 0); //Blank screan
      while(touch_Get(TOUCH_STATUS) != TOUCH_PRESS); //wait for touch 
      gfx_Set(CONTRAST, 9); //Turn the screen back on
      sys_SetTimer(TIMER0, SCREEN_TIMEOUT); //Reset the screen timeout timer
      if(touch_Get(TOUCH_STATUS) == TOUCH_PRESS) //If there is a touch, reset the timer
      sys_SetTimer(TIMER0, SCREEN_TIMEOUT); //Reset the screen timeout timer

      I hope someone finds this usefull.


      • #33


        I was considering doing much the same thing with a CAP but I think you will find that the display uses too much power to make that practical. Unless, of course, you put a pretty big cap there. My solution is to add a battery to the device which will only be used for the time it takes the module to shut down. This can be done with a 9V, 5V regulator, 555 timer and a diode (I think). The other possible way is to have a powersupply with a backup battery that will be turned off by an output pulse from the 4DG module when it sees the main power has failed.

        Let me know how you go with this. I am using a battery operated device so I am able to use a push-on push-off circuit...


        • #34

          BUMP: I'm trying to find the location of the WARNING referenced at the top of this thread, in the user manual .. I've looked all over uOLED-96-G1GFX-DS-rev2.pdf but cannot find it described anywhere - can someone please point me in the right direction as I feel I am missing some vital information on this module and before I attempt to implement it in my project I want to be sure I have all the details.

          Thanks in advance ..
          ibi sum


          • #35

            You will find the warning in the second file attached in the very first post of this thread.


            • #36

              Sorry .. but this is a rotten way of warning your customers about the dangers of using this product improperly. I fail to see how an obscure posting in this forum is sufficient diligence for such an issue as potential total damage to the product, frankly.

              As I may well have totally destroyed my OLED-96 through the simple act of plugging it in, as per the instructions given in the 4D Systems documentation, and not being aware of the power-down sequence as a result of omitted information on the part of 4D systems, I am thus extremely dissatisfied with my purchase from this company!

              Please put the warning about damage to the device in an obvious place on the product packaging itself, or make this document - from some company called "Univision Technology, Inc." (wtf, I thought I bought a product from 4D Systems?) available on the product information page on your main site.

              What is the SSD1339?
              ibi sum


              • #37

                Is this really that much of an issue? I've plugged / unplugged mine hundreds of times without powering off the display I just really lucky, or is this like a 1 in a million chance kind of thing?
                Best Regards,


                • #38

                  I plugged mine in three times upon receiving it, to just enjoy its brilliance, and now it illuminates no more .. so yeah, I think its an issue. BIG FAT WARNINGS, please.
                  ibi sum


                  • #39

                    Do the newer LCD display modules such as the µLCD-32PT(GFX) still have power down concerns? Having to power down in a certain sequence. I've seen direct references to OLED displays having this issue but only vague references to LCD. I found this post on the forum, but it seemed dated and irrelevant. If the µLCD-32PT(GFX) requires a specific power down sequence, what is it, where can I find details about it? I cannot find it n the documentation. Thanks


                    • #40

                      I am also wanting to use the µLCD-32PT(GFX) for an in car display and am a bit confused about the whole power down issue and if it applies to this display. I have been through the ?LCD-32PT(GFX) 3.2” LCD Display Module Data Sheet Document Date: 22nd July 2010 Document Revision: 3.0 and can find no warnings about a power down sequence, as mentioned in the first post to this thread.

                      smcmanus wrote: There have been a number of questions asked about the danger of damaging the OLED and LCD displays by failing to observe the power down sequence detailed in the User Manuals.
                      I would have expected a warning to be in section 7, page 15 of the above mentioned document if it was relevant to the µLCD-32PT(GFX). The data sheet for the bare lcd display also makes no mention of a power down procedure, at least that I could find, and the attachments to the post mentioned above only show OLED devices.

                      So do I or don't I need to follow a power down procedure for the µLCD-32PT(GFX) and if I do is it sufficient to call the function ProgramExit() and then cut the power?


                      • #41

                        There is no specific power-down requirement for LCD displays. Power can be interrupted during any type of operation and it will not cause any adverse effects.


                        • #42

                          Thanks for the clarification meldavia, maybe this sticky at the top of the micro-LCD forum could be clarified, it sent me on a bit of a wild goose chase!



                          • #43

                            4dTechSupport wrote: In order to proceed with the warranty and repair, you need to get back to your place of purchase with the invoice details. They will be able to assist. The product is covered for three months warranty.
                            I have just to see this thread, and I am very surprised and angry.

                            My uOLED-160-G1 (SGC) is also broken, because I have disconnected the power suppy.
                            I bought it on 2011-02-27, so in order to proceed with the warranty and repair, what do I have to do? Do you have a re-seller in Spain, to resolve it?


                            • #44

                              Would it help address this issue any if a big capacitor (e.g. .47 uF) was put across the power/gnd pins at the display connector to slow the ramp up and ramp down of display power?
                              Jim Edwards


                              • #45

                                Hi, I think I've suffered a failure too ... although I've been very carefull in shutting down the display.
                                Can someone confirm its just the display (i.e. the screen) which dies, in my case I'm pretty sure the processor is still running because I'm using the touch screen to control other things and that seems to be working even though I can't see anything on the screen.

                                And are these things repairable?