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DotStar Strip resistors?
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DotStar Strip resistors?

by dstaley on Tue Jan 08, 2019 11:25 pm

Today I received a 1m DotStar strip (which is working wonderfully by the way), and I would like to cut it up into smaller strips of 6 LEDs each. I noticed on the strip two components labeled "R1" and "R2" with 151 on them.

Am I correct in assuming these are resistors?

If so, are they connected to the clock line, data line, or both (i.e. one resistor for each line)?

Finally, if I wanted to replicate their behavior on a cut segment, would it be okay for there to be a wire in between the resistor and the LED strip? (So microcontroller -> wire -> resistors -> wire -> LED strip)

dstaley
 
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Joined: Mon May 08, 2017 6:49 pm

Re: DotStar Strip resistors?

by oesterle on Wed Jan 09, 2019 5:51 pm

Hi, dstaley!

Those are likely 150Ω resistors. They should be included in the cut segment, and you shouldn't need to wire to anything but the terminals provided at each cutline.

Can you post a sharp image of a section of your strip, including LED, resistor(s), and cutlines? (800 x 600 resolution works well.)

Cheers,

Eric

oesterle
 
Posts: 411
Joined: Tue Sep 17, 2013 11:32 pm

Re: DotStar Strip resistors?

by dstaley on Wed Jan 09, 2019 9:01 pm

oesterle wrote:Hi, dstaley!

Those are likely 150Ω resistors. They should be included in the cut segment, and you shouldn't need to wire to anything but the terminals provided at each cutline.

Can you post a sharp image of a section of your strip, including LED, resistor(s), and cutlines? (800 x 600 resolution works well.)

Cheers,

Eric


IMG_20190109_163926.jpg
IMG_20190109_163926.jpg (204 KiB) Viewed 40 times


You can see the resistors on the left hand side. I assume if I cut the strip that I'd need to add my own resistors on the new segment (assuming the segment would be a subsegment between existing resistors on the strip [i.e. a segment of only three LEDs]).

dstaley
 
Posts: 9
Joined: Mon May 08, 2017 6:49 pm

Re: DotStar Strip resistors?

by oesterle on Wed Jan 09, 2019 9:43 pm

Adafruit_support_bill answered a similar question here on the forums, saying that adding resistors to clock and data lines near the beginning of the cut strip is "not a bad idea."

I'd try the Through-Hole Resistors - 470 ohm 5% 1/4W - Pack of 25, which Adafruit recommends for NeoPixel data inputs.

oesterle
 
Posts: 411
Joined: Tue Sep 17, 2013 11:32 pm

Please be positive and constructive with your questions and comments.