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Help - Trying to put a Blikt on a PI with a POE hat
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Help - Trying to put a Blikt on a PI with a POE hat

by malcolm_b_anderson on Fri Jun 04, 2021 10:58 pm

I have a 4 node stack of pi's in a dogbone "case"

I'm trying to find a pin extender that will go through a POE hat
and allow me to install a Pimoroni Blikt! (3195)
I got 4 extenders, but they don't quite fit through the POE hat.

Do you have some suggestions on what I should get.
The tolerances seem kind of tight.
I see the extra tall header (1979), but the base seems to be twice the height as
the base for what I ordered (4079).

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Re: Help - Trying to put a Blikt on a PI with a POE hat

by adafruit_support_mike on Sun Jun 06, 2021 7:55 pm

This might work:

https://www.adafruit.com/product/2223

It has longer pins than PID 4079, but the plastic housing is about the same height.

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Re: Help - Trying to put a Blikt on a PI with a POE hat

by malcolm_b_anderson on Sun Jun 06, 2021 11:08 pm

Thank you. I will give it a try.

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Re: Help - Trying to put a Blikt on a PI with a POE hat

by malcolm_b_anderson on Sun Jul 25, 2021 3:53 pm

adafruit_support_mike wrote:This might work:

https://www.adafruit.com/product/2223

It has longer pins than PID 4079, but the plastic housing is about the same height.


Unfortunately that didn't work.

After making the decision to, as gently as I could, ripping the 2x20 housing off the POE hat and using the extender you recommend,
I took the bottom Pi out of my cluster, took the hat off, and I did an eyeball inspection.

What I found is that the 2x20 extender base is still 3 - 4 mm to high for the hat to sit on the extender that come with the POE hat.
I would have to unsolder and replace the 2x20 pins on the Pi for that to work, which wouldn't work for *so* many different reasons, and well, that's not going to happen.

Not having the 2x20 pins built into the POE hat is a design mystery to me, unless this second generation POE hat is still a proof of concept.
The hat is a great convenience for removing the need to have 4 additional cables (power) plugged into my stack,
but as it stands, the 2x20 pins might as well be clipped off for all the good they are doing me under the hat.

The 2x20 blinkit that I have would be great for adding status displays on my cluster.
What I require is a 2x20 pin extender that fits comfortably between the Pi and the POE hat.

Does anyone have contact information for the POE hat manufacturers, I'm hoping that maybe they have a solution.

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Re: Help - Trying to put a Blikt on a PI with a POE hat

by alphanumeric on Mon Jul 26, 2021 4:33 am

This might work, you'd have to solder it to the Pi's GPIO, then plug the POE hat on top. Then a male header and the Blinkt on the other end. The POE hat is going to sit a little higher but with a little luck still work. No real need to solder all the pins, I'd just solder the ones used by the Blinkt.
I can't guarantee it will work, up to you if you want to try it.
https://pinout.xyz/pinout/blinkt
https://shop.pimoroni.com/products/pico-hat-hacker

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Re: Help - Trying to put a Blikt on a PI with a POE hat

by alphanumeric on Mon Jul 26, 2021 6:43 am

It just occurred to me that the LED Shim is basically a bigger longer Blinkt, and doesn't require any soldering. It will take up minimal space on the header, just the thickness of the circuit board.
https://www.adafruit.com/product/3831
https://shop.pimoroni.com/products/led-shim

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Re: Help - Trying to put a Blikt on a PI with a POE hat

by malcolm_b_anderson on Sat Jul 31, 2021 11:20 pm

malcolm_b_anderson wrote:Does anyone have contact information for the POE hat manufacturers, I'm hoping that maybe they have a solution.


Who would I talk with to find the contact info for the POE hat manufacturer?

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Re: Help - Trying to put a Blikt on a PI with a POE hat

by malcolm_b_anderson on Sat Jul 31, 2021 11:21 pm

alphanumeric wrote:It just occurred to me that the LED Shim is basically a bigger longer Blinkt, and doesn't require any soldering. It will take up minimal space on the header, just the thickness of the circuit board.
https://www.adafruit.com/product/3831
https://shop.pimoroni.com/products/led-shim


I will certainly give this shim a try.

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Re: Help - Trying to put a Blikt on a PI with a POE hat

by adafruit_support_mike on Sun Aug 01, 2021 4:37 am

malcolm_b_anderson wrote:Who would I talk with to find the contact info for the POE hat manufacturer?

The POE Hat is made by the RasPi Foundation, who make the RasPi itself:

https://www.raspberrypi.org/forums/

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Re: Help - Trying to put a Blikt on a PI with a POE hat

by malcolm_b_anderson on Sun Aug 08, 2021 5:43 pm

Thanks Mike, that's exactly the information I was looking for.

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Re: Help - Trying to put a Blikt on a PI with a POE hat

by malcolm_b_anderson on Sun Aug 08, 2021 5:47 pm

malcolm_b_anderson wrote:
alphanumeric wrote:It just occurred to me that the LED Shim is basically a bigger longer Blinkt, and doesn't require any soldering. It will take up minimal space on the header, just the thickness of the circuit board.
https://www.adafruit.com/product/3831
https://shop.pimoroni.com/products/led-shim


I will certainly give this shim a try.


Sadly the above LED ship butts right up against the screws for the POE hat off sets.
It's kind of hard to see in the picture, my camera had difficulty getting the shot showing the shim covering the yellow guide circle on the PI.

The POE had solves the problem of having having to run a power wire to your PI, but by effectively eliminating the 2x20 pin set on the PI, it creates more problems for people who want to use the 2x20 pins.
Attachments
LED shim not allowing for POE hat standoffs.png
LED shim not allowing for POE hat standoffs.png (565.56 KiB) Viewed 40 times

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Re: Help - Trying to put a Blikt on a PI with a POE hat

by adafruit_support_mike on Sun Aug 08, 2021 7:54 pm

Yeah, the RasPi Foundation broke its own spec for Hats with the PoE Hat.

To be fair, I don’t think there’s an obvious solution that would do better without creating its own problems. Regardless, the PoE Hat does tend to limit your chances to connect anything else.

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Please be positive and constructive with your questions and comments.