Author Topic: SOLVED: How to set jumpers on PiCap for WS2812? Not lighting up.  (Read 451 times)

Offline gpvillamil

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Re: How to set jumpers on PiCap for WS2812? Not lighting up.
« Reply #15 on: January 04, 2019, 04:29:06 PM »

I take it the attached picture means that putting a jumper between 2&3 sets output to 5v.


What does the other jumper do? It appears to be labelled PWR PI on the top surface.

The power jumper layouts are printed on the "underside" of the PiCap

As far as Test Mode and output, do you have the RasPi in Master or Standalone mode?

Offline dkulp

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Re: How to set jumpers on PiCap for WS2812? Not lighting up.
« Reply #16 on: January 04, 2019, 04:50:14 PM »
Those are for setting the power going INTO the Pi from the power connector on the board.  There isn't a way to power the pixels from the Pi directly.  You have to have power going into the power connector on the hat.
Dan Kulp

Offline Bwinter

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Re: How to set jumpers on PiCap for WS2812? Not lighting up.
« Reply #17 on: January 04, 2019, 04:59:22 PM »
Are you getting 5V out of the actually connector (that they pixels are connected to)?

Offline JonB256

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Re: How to set jumpers on PiCap for WS2812? Not lighting up.
« Reply #18 on: January 04, 2019, 05:38:43 PM »
For 5v, I just hang that "extra" jumper off the #4 pin, doing nothing. Otherwise, you'll lose that little sucker.

Offline gpvillamil

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Re: How to set jumpers on PiCap for WS2812? Not lighting up.
« Reply #19 on: January 07, 2019, 12:34:17 PM »

Ah great, that helps.


So if you have a 5v 4A supply, you just set the jumper bridging pins 2 & 3?


(What does it do, really? Are you just bypassing a 5v regulator in this case?)

Those are for setting the power going INTO the Pi from the power connector on the board.  There isn't a way to power the pixels from the Pi directly.  You have to have power going into the power connector on the hat.

Offline gpvillamil

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Re: How to set jumpers on PiCap for WS2812? Not lighting up.
« Reply #20 on: January 07, 2019, 01:17:03 PM »

Thank you, good tip.

For 5v, I just hang that "extra" jumper off the #4 pin, doing nothing. Otherwise, you'll lose that little sucker.

Offline gpvillamil

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Re: How to set jumpers on PiCap for WS2812? Not lighting up.
« Reply #21 on: January 07, 2019, 03:08:32 PM »
Everything is working great.


I needed to provide 5V to the connector on the PiCap and set the jumper to the 5V position.


I can now drive the pixel strip directly from Python, using both the Adafruit neopixel library, and the rpi_ws281x library.


Thank you all for your help!

 

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