Defective Dotstar LED strips

Forum Administrative - NOT PROJECT OR "HELP"

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
albarrett
 
Posts: 3
Joined: Tue May 05, 2015 12:00 pm

Defective Dotstar LED strips

Post by albarrett »

Please refer to: Order Confirmation No: 758711-4948337577.
2 x Adafruit DotStar Digital LED Strip - Black 144 LED/m - One Meter (BLACK)
[ID:2241] = $149.90

The above two Dotstar 1 meter strips which I received are defective and all
LEDs display the wrong colors. I looked at the LEDs under a microscope, and
the dies are all assembled off-center, as compared to a known good LED. I
have purchased several other Dotstar strips in the past, and they all
display correctly correctly.

Please send me replacement Dotstar LED strips, and please verify that they
work correctly first. The problem is definitely tied to this batch of strips.

Thank you.

User avatar
adafruit_support_mike
 
Posts: 67446
Joined: Thu Feb 11, 2010 2:51 pm

Re: Defective Dotstar LED strips

Post by adafruit_support_mike »

The trouble you're seeing involves the bit-sequence order for color data.

Different versions of the PWM controller accept data with the R, G, and B components in different orders. The initializer function for the Adafruit_DotStar class accepts an 'order' parameter that tells the code how to arrange things. The default (set in the header) is GBR order, but we've defined constants for all six possibilities.

Setting one pixel to 'red', one to 'green', and one to 'blue' under the default order will show you how the values are transposed, and what order to use.

Unfortunately our supplier changes the bit order occasionally without telling us. We guarantee that the pixels will work once you find the correct order, but can't guarantee a specific bit order.

If that doesn't work for your project, we can arrange a return and refund.

User avatar
albarrett
 
Posts: 3
Joined: Tue May 05, 2015 12:00 pm

Re: Defective Dotstar LED strips

Post by albarrett »

Mike,
Thank you for your reply. Yes, the latest Dotstar LED strips are behaving as if the byte ordering is swapped around. The green and blue seem to be swapped inside the LEDs. Unfortunately, we were planning to use these strips in standard production products, and ramp up the quantities. It is not really feasible for us to have to calibrate each system to a particular LED strip. It's much preferable for us to have a consistent product. Do you know if the supplier of the APA102 LED just made one bad batch of them, or if this is a recurring problem? Do you know of any other suppliers of the APA102 LEDs that would be able to guarantee a specific byte ordering?

Thank you.
Al

User avatar
adafruit_support_mike
 
Posts: 67446
Joined: Thu Feb 11, 2010 2:51 pm

Re: Defective Dotstar LED strips

Post by adafruit_support_mike »

It isn't normal, but it happens occasionally. We aren't set up to be a production supplier, with product-change notifications and so forth. With the agreements we have we cannot provide the supplier.

Locked
Please be positive and constructive with your questions and comments.

Return to “Administrative (closed)”