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16x32 RGB LED Matrix Rows Mis-addressed?
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Please be positive and constructive with your questions and comments.

16x32 RGB LED Matrix Rows Mis-addressed?

by NJohnston_FGI on Tue Sep 26, 2017 6:32 pm

Recently acquired an Adafruit 16x32 RGB LED Matrix from Newark because Adafruit was out of stock.

I'm using a Metro, with the suggested 5v 2A power supply, and wired according to tutorial (Triple checking everything). When I ran some of the example code I was met with weird outputs. Trying to troubleshoot the issue I hacked apart the "Scrolltext demo" and coded up a quick script to flash each pixel in order individually and was met with interesting consequences. It appears as though the rows are mis-addressed on the board.

Code: Select all | TOGGLE FULL SIZE
#include <Adafruit_GFX.h>   // Core graphics library
#include <RGBmatrixPanel.h> // Hardware-specific library

#define CLK 8  // MUST be on PORTB! (Use pin 11 on Mega)
#define LAT A3
#define OE  9
#define A   A0
#define B   A1
#define C   A2
RGBmatrixPanel matrix(A, B, C, CLK, LAT, OE, true);

void setup() {
  matrix.begin();
  Serial.begin(9600);
}

void loop() {
 
  unsigned char x, y;
 
  //Loop through all pixels
  for(int y=0; y<matrix.height(); y++){
    for(int x=0; x<matrix.width(); x++){
        // Draw Pixel White
        matrix.drawPixel(x, y, matrix.Color333(7, 7, 7));
        matrix.swapBuffers(true);
        delay(50);
        //Black Pixel
        matrix.drawPixel(x, y, matrix.Color333(0, 0, 0));
        matrix.swapBuffers(true);
        delay(25);
        Serial.print("(");
        Serial.print(x);
        Serial.print(",");
        Serial.print(y);
        Serial.print(")");
        Serial.println("");
      }
  }
  // Update display
  matrix.swapBuffers(true);
}


The attached image is how the rows lit up. (See red numbers to right)
16x32 incorrect row order_SM.jpg
16x32 incorrect row order_SM.jpg (817.64 KiB) Viewed 157 times

I'm convinced but would like to verify that there is a manufacturing issue with this unit.

NJohnston_FGI
 
Posts: 3
Joined: Tue Sep 26, 2017 6:17 pm

Re: 16x32 RGB LED Matrix Rows Mis-addressed?

by adafruit_support_rick on Tue Oct 03, 2017 10:23 am

I wonder if that's a 1/4 scan panel? Our panels are 1/8 scan.
I'll ask somebody who might know...

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Location: Buffalo, NY

Re: 16x32 RGB LED Matrix Rows Mis-addressed?

by dearner on Tue Oct 03, 2017 10:38 am

All of the panels I've gotten have the pitch, size and scan rate printed on the PCB on the back. So, one of my 32x32 P6 1/8 scan ratio panels says "P6(3535)32x32-8S-V1.6" on the board itself. You could probably look and see if your panel is a 1/4 or 1/8 scan.

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Joined: Sun Nov 06, 2016 12:54 am

Re: 16x32 RGB LED Matrix Rows Mis-addressed?

by NJohnston_FGI on Tue Oct 03, 2017 11:09 am

As stated before, I purchased the board through Newark/Element14 because Adafruit was out of stock and I need this for a work project ASAP. Newark references this unit as an Adafruit board (PN:420), calls out a 1:8 scan rate, and I was recommended to contact Adafruit for support or confirmation that the board was defective.

Link where I purchased the board from: http://www.newark.com/adafruit-industries/420/led-display-alphanumeric-16x32/dp/53W5941

I'd like it to behave as expected and respond normally to tutorial code.

Below is a picture of the entire back of the board.
As relevant numbers, I see:
IFH6-32x16-8S-V1.1
P6-16x32-A
Attachments
IMG_20171003_085636_SM.jpg
IMG_20171003_085636_SM.jpg (871.46 KiB) Viewed 105 times

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Re: 16x32 RGB LED Matrix Rows Mis-addressed?

by adafruit_support_rick on Wed Oct 04, 2017 8:08 am

I'm waiting to hear back from our expert. Meanwhile, it's *really* unlikely for the matrix to be wired wrong internally.
Can you post some pictures of your wiring?

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Location: Buffalo, NY

Re: 16x32 RGB LED Matrix Rows Mis-addressed?

by NJohnston_FGI on Thu Oct 05, 2017 11:57 am

I rewired again according to the tutorial and it looks like I had the B and C (A1 and A2) wires switched. Thus causing the weird behavior. I guess I just missed this switch even after doublechecking my wiring.

Thank you for the advice. Please close ticket.

-Nick

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Posts: 3
Joined: Tue Sep 26, 2017 6:17 pm

Re: 16x32 RGB LED Matrix Rows Mis-addressed?

by adafruit_support_rick on Fri Oct 06, 2017 11:08 am

No problem! Glad to hear you found the problem

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Posts: 34768
Joined: Tue Mar 15, 2011 11:42 am
Location: Buffalo, NY

Please be positive and constructive with your questions and comments.