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Thread: BuyDisplay ER-TFTM050A2-3(CTP) 5" capacitive touch ra8875

  1. #1
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    BuyDisplay ER-TFTM050A2-3(CTP) 5" capacitive touch ra8875

    I've been going through the connection doc for the TFT display .. 40 pin ..`

    for the Capacitive touch there is a WAKE command .. which puts the touch IC to sleep when asserted low... as I don't want it to sleep .. do I leave it floating or tied high ?
    can't seem to source that out..

    new to this display .. still sorting it out ..

    SPI/i2c are fine and power is sorted out ... just wondered if I needed other pins tied to get it to fire up .

    Thanks

  2. #2
    Senior Member+ KurtE's Avatar
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    I don't have this display, I have an older version of their 5". Looks like this one is setup more like most of their other newer ones, like the 4.3" version I have or their 7" RA8876 one.

    The PDF for My 4.3" one says NC for pin 32.

    The PDF for the 7" RA8876 says something differt: Chip Select Input. Active Low logic Input. This input provides the dual function of initiating conversations on the XPT2046 and also enables the Serial input/output register.


    So in your case ??? I am not sure. My guess is I would probably try hooking up to 3.3v or an IO pin that can go either way... May have to look at my adapter boards and see if I can handle this version.

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    Thanks for the reply Kurt ...well ..I'm wired up but not a peep out of it running the simple initialization script ...a little stumped to say the least ...dont even see the backlight flash ...new display ..checked the jumper configurations and they all check out for 4 wire spi ...and 5v power ...going to have to spend some more time to sort it out

  4. #4
    Senior Member+ KurtE's Avatar
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    Not sure what library you are using... Also not sure what board you are connecting to.

    If you use the version of RA8875 which a few of us made work on T4s and I pretty sure I tried with T3.6 or 3.5, now I believe the version installed by Teensyduino is reasonably up to date.

    Otherwise @mjs513 has probably the most up to date version in his github, mine is also probalby in sync with his. We use the RA8875_t4 branch.

    This all all started off with the version from sumotoy. But he has not been active for a few years now.

    Backlight - I have not looked at this boards defaults but depending on solder jumpers J15/J16 it is either external, or internal.
    If External (My RA8876 came this way) you need to run pin 14 to either an IO pin you pull high or use PWM on.

    or if you set to internal: Then your sketch may have to turn on the backlight.
    Something like: tft.backlight(true);

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    Yes ..teensy 4.0 ...over spi ...this board has multiple grounds as well as multiple lines for supply voltage..5 lines for ground 4 for +5 ...I'm starting to wonder if the current draw is too high if I run it off usb and perhaps it's not coming up ...anyhow ..I'm on the latest and greatest arduino/teenyduino UI ...I'll fuss with it and see what happens ...but a bit stymied at the moment ..I'm missing something and it has to be simple ..

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    Kurt .. I'm up and running .. I reviewed the documentation and somewhere in there I had the reset tied high .. anyhow ..pulled the wire and we're all good ..Silly me!

    now to work my way over to the touch component... sorry to waste your time ...

    I pulled all the wiring off the 40 pin header and re-ran it and had one wire too many .. then it clicked ...

    So back to my SDR project ... thanks for taking the time for me..

  7. #7
    Senior Member+ KurtE's Avatar
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    I have run their 7" RA8876, 5" RA8875 (older version board) 4.3" RA8875 (similar to your layout) as I mentioned in previous post.
    And I have run all of them so far off of the VUSB power.

    Might help if we saw picture of your wiring and maybe picture of the back of your display that maybe someone might see if one of the jumpers looks wrong.

    My first one of theirs came with 3 wire SPI, which I then needed to update.

    Also might help to see again what sketch (which library) you are trying.

    Again that way we can see if things like you have the right CS pin selected.

    Also do you have the Reset pin connected and selected in sketch.

    A couple of times I thought my display was not working, only to find out the Reset pin was not connected and floating which left it in a bad state.

    Sometimes it can be something like wrong display type selected in the init.

    For example here is one of the examples (I have not tried it in awhile so not sure if still works.
    Code:
    /*
    this sketch demostrate the ability to rotate screen .
    since his introduction, setRotation created some problems in library
    because RA8875 does most of his stuff internally so from library version 0.69b21
    code has many changes to fix the rotation issues.
    
     */
    
    #include <SPI.h>
    #include <RA8875.h>
    
    #define RA8875_CS 10 //any digital pin
    #define RA8875_RESET 9//any pin or 255 to disable it!
    
    RA8875 tft = RA8875(RA8875_CS,RA8875_RESET);//arduino's
    
    
    
    void setup() 
    {
      Serial.begin(38400);
      //long unsigned debug_start = millis ();
      //while (!Serial && ((millis () - debug_start) <= 5000)) ;
      //Serial.println("RA8875 start");
      //  begin display: Choose from: RA8875_480x272, RA8875_800x480, RA8875_800x480ALT, Adafruit_480x272, Adafruit_800x480
      tft.begin(RA8875_800x480);
    }
    
    
    uint8_t rot = 0;
    
    void loop() 
    {
      tft.fillWindow();
      tft.setRotation(rot);
      tft.setCursor(0,0);
      tft.print("[rotation ");
      tft.print(rot);
      tft.print("]");
      tft.setCursor(100,0);
      tft.print("txt shifted to X100");
      tft.setCursor(0,20);
      tft.print("txt shifted to Y20");
      tft.drawCircle(tft.width()/2,tft.height()/2,50,RA8875_GREEN);
      tft.drawRect((tft.width()/2)-50,(tft.height()/2)-25,100,50,RA8875_YELLOW);
      tft.drawEllipse(tft.width()/2,tft.height()/2,50,25,RA8875_CYAN);
      tft.drawTriangle((tft.width()/2)-50,(tft.height()/2)-25,tft.width()/2,(tft.height()/2)+25,(tft.width()/2)+50,(tft.height()/2)-25,RA8875_RED);
      tft.drawPixel(tft.width()/2,tft.height()/2,RA8875_WHITE);
      tft.drawFastVLine(tft.width()/2,(tft.height()/2)-60,60,RA8875_RED);
      tft.drawFastHLine((tft.width()/2)-60,tft.height()/2,60,RA8875_RED);
      delay(3000);
      if (rot > 3) rot = 0;
      rot++;
    }
    This one is configured for I think the display you have (800x480 Not Adafruit)... But you should check to make sure what you are running is configured properly\

    EDIT Looks like we cross posted... Glad you are up and running!

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