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Unresponsive pixels on Dotstar Disk
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Unresponsive pixels on Dotstar Disk

by mhzmaster on Mon May 09, 2016 8:57 pm

Hi,

I recently purchased a Dotstar Disk (https://www.adafruit.com/product/2477) and am having issues communicating with all pixels on the display. After connecting to Arduino and running test code, the first 65 pixels along the outer edge work consistently, as expected. However the remaining inside pixels are either off or running at full bright white.
Occasionally if I let a program run long enough, these pixels light up in colors. But this never happens in a predictable or controllable way.

Initially was running sample code from (https://learn.adafruit.com/lightship-le ... -over-wifi) on a Feather M0. Switched to an Arduino Uno to see if a 5V microcontroller would help. No luck. I am now testing with a very simple test sketch lighting up LEDs one at a time.

I have a 5V 10A power supply connected like so:
IMG_6200.JPG
IMG_6200.JPG (188.1 KiB) Viewed 775 times


I suspect this is hardware issue, but have reached the limits of my knowledge on how to test for issues. How can I proceed?

Many thanks!

mhzmaster
 
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Re: Unresponsive pixels on Dotstar Disk

by hiduino on Mon May 15, 2017 8:46 pm

Do you get the same results testing with the M0 and the Uno?

Can you show the test code you are trying with the Uno?

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Re: Unresponsive pixels on Dotstar Disk

by dpentecost on Tue May 16, 2017 6:19 pm

Sorry to jump in, but I am also having problems with the Dotstar Disk.

I am running through the Feather MO Lightship exercise, and have gotten the Feather MO working over WiFi, and the OPCpianoRoll and OPCvideo Processing sketches working fine with a Dotstar strip. But using the disk (powered with a 5V 10A supply) and the OPC_LEDDisc_Scroll sketch, I get a disk full of randomly lighting LEDs. Sometimes I can just barely see the Adafruit letters scroll though amid the noise. I know that there is supposed to be some low level flickering, but this is full strength blinding randomness.

I see the multiple matrix exercise - dividing a video between several Dotstar matrices and a Disk - in a video so I know someone has gotten this to work. Where is more information about that project?

The Lightship tutorial is great as far as it goes - Feather MO and LED Matrix and strip - but there is really very little info about the Disk, and the one scroll sketch is not working.

FWIW, I bought one disk and got this problem, and thought maybe I had fried it resoldering a wire from the connector that got loose in transit. But I bought a new one and out of the box I'm getting the same thing.

Has anyone gotten the disk to work properly? What am I missing here?

Thanks!

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Re: Unresponsive pixels on Dotstar Disk

by hiduino on Tue May 16, 2017 10:49 pm

@dpentecost, Be aware that the Dotstar Disk are treated as a strip not a matrix. So you should declare it as a Dotstar strip in your code.

See the datasheet, https://cdn-shop.adafruit.com/product-files/2477/2477.pdf, for the LED sequence.

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Re: Unresponsive pixels on Dotstar Disk

by chemdoc77 on Fri May 19, 2017 12:09 pm

Check out the following which includes code that works on a DotStar Disk:

https://plus.google.com/+JasonCoon1/posts/1kGbQeyMBuH

You can easily modify the code in case you do not have an IR remote controller.

This should allow you to test your DotStar Disk with code that works.

Finally, does your MCU have enough RAM to run 255 DotStars along with your code?

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Re: Unresponsive pixels on Dotstar Disk

by dpentecost on Sat May 20, 2017 9:11 am

Thanks for the suggestions. I will try again this weekend. And yes, I have tried sketches that treat the disc as a strip - still get massive noise on all the pixels.

Also, I am using the Feather MO as in the main lightship tutorial. I'm guessing there is not a problem with the capacity of the MCU in my case.

dpentecost
 
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Re: Unresponsive pixels on Dotstar Disk

by chemdoc77 on Sun May 21, 2017 7:40 pm

Hi dpentecost:

You said that you are using a 5 volt power source for the DotStar disk and you are using a Feather MO. I believe that the Feather MO has a 3.3 volt output. You probably need to use a level-shifter between the Feather MO and the DotStar disk. This is a good one:

https://www.adafruit.com/product/1787

Best Regards,
Chemdoc77

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Re: Unresponsive pixels on Dotstar Disk

by dpentecost on Mon May 22, 2017 12:58 am

Thanks, but the tutorial specifically recommends a 5V 10A supply.

"You'll need a lot of power to fully light up this disk, so be sure to pick of a 5V 10A power supply!"

Power for the Feather is another matter. But everything I have seen in the wiring diagrams shows that the signals from the Feather (not the power) will work to drive the matrix (I don't have one to test). And my setup works for a strip.

Back to testing.

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Re: Unresponsive pixels on Dotstar Disk

by blingdisk on Wed Jan 31, 2018 3:07 am

My results got much better after did the following:

A) Connected the ground from my power supply to the Arduino board, even though the power supply itself isn't grounded.
B) Cranked my power supply up to 5.5v. I thought it was already there but found out it wasn't after measuring the output
C) Used Adam's lib written for FastLed: https://maniacallabs.com/2015/05/04/rev ... star-disk/

It's not perfect yet. Next steps are adding the capacitor to the power supply output and another resistor to the data input on the Dotstar Disk.

blingdisk
 
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Re: Unresponsive pixels on Dotstar Disk

by blingdisk on Fri Feb 23, 2018 7:51 pm

The resistor helped on the data line. I am using 470kohm right now.

I have question though. What capacitor to I use? The best practices article says to put a 1000uf capacitor between the +/- on the power supply. I can't seem to find one at the right voltage and rating. Can someone point out the one which is most ideal for the large draw on the Dotstar disk?

For example, this one is 1000uf but not rated for 5v.
https://www.mouser.com/ProductDetail/Un ... NvSrZas%3d

The disk is ALMOST showing my patterns properly, so I am hoping this last step will do the trick.

blingdisk
 
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Re: Unresponsive pixels on Dotstar Disk

by blingdisk on Thu Mar 08, 2018 11:37 pm

Bump

blingdisk
 
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Re: Unresponsive pixels on Dotstar Disk

by Disciple on Fri Mar 09, 2018 1:30 am

Hi. I'm a hobbyist with a bit of practice using NeoPixels, which have some features in common with DotStars. The capacitor used to suppress power badness can have numbers above the recommendations. I use caps at 2200uf at 6V, my father uses the ones sold at Adafruit, 4700uf at 10V. Both work flawlessly, and the same principle works for DotStars. Hope this helps.

Hallelujah!
Disciple

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Re: Unresponsive pixels on Dotstar Disk

by blingdisk on Thu Mar 22, 2018 12:12 am

After doing all the things I mentioned above, I am still getting spurious results. Please help.

Here's my current setup:
20180321_204614.jpg
20180321_204614.jpg (397.36 KiB) Viewed 335 times


- 4700uf 10v capacitor on the power supply
- 0-500ohm resistor on data pin (i've tried them all)
- data on 11 and clock on 13 because some code is SPI
- ground between power supply and GND on Arduino

My latest code is just an alteration of the Adafruit dotstar example. I can turn on any LED, in this case the 10th, with a refresh every second.

Code: Select all | TOGGLE FULL SIZE
#include <Adafruit_DotStar.h>
// Because conditional #includes don't work w/Arduino sketches...
#include <SPI.h>         // COMMENT OUT THIS LINE FOR GEMMA OR TRINKET
//#include <avr/power.h> // ENABLE THIS LINE FOR GEMMA OR TRINKET

#define NUMPIXELS 255 // Number of LEDs in strip

// Here's how to control the LEDs from any two pins:
#define DATAPIN    11
#define CLOCKPIN   13

// Hardware SPI is a little faster, but must be wired to specific pins
// (Arduino Uno = pin 11 for data, 13 for clock, other boards are different).
Adafruit_DotStar strip = Adafruit_DotStar(NUMPIXELS, DOTSTAR_BRG);

void setup() {

#if defined(__AVR_ATtiny85__) && (F_CPU == 16000000L)
  clock_prescale_set(clock_div_1); // Enable 16 MHz on Trinket
#endif

  strip.begin(); // Initialize pins for output
  strip.show();  // Turn all LEDs off ASAP
}

int      head  = 10, tail = -10; // Index of first 'on' and 'off' pixels
uint32_t color = 0xFF0000;      // 'On' color (starts red)

void loop() {
  strip.setPixelColor(head, color);
  strip.show();                    // Refresh strip
  delay(1000);                     // Pause
}


Sometimes, it shows one LED (green, but should be red?) lit up. That's close to what it should do:
20180321_204623.jpg
20180321_204623.jpg (398.14 KiB) Viewed 335 times


It refreshes ever second and goes back and forth randomly between random and almost working and working. Some other samples:
20180321_204633.jpg
20180321_204633.jpg (289.95 KiB) Viewed 335 times


I can't upload my last image, but it's much more random that the previous one.

I have tried many other libraries/demos and my own code. Everything acts partially random like I described here.
Seems like I am not the only one with these issues. Is the Disk faulty or am I still doing something wrong?

blingdisk
 
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Re: Unresponsive pixels on Dotstar Disk

by blingdisk on Fri Mar 23, 2018 10:32 am

Bump

blingdisk
 
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Re: Unresponsive pixels on Dotstar Disk

by blingdisk on Sat Apr 07, 2018 12:56 pm

Okay, I am giving up on the Dotstar Disk. Can I get a refund? It's faulty.

blingdisk
 
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