Io510k
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Through header -two-way - up/down - front/back

Wed Nov 20, 2019 1:07 am

All - I am looking for a 2x20 pin header that allows shields to be assembled from both direction on the RPi zw. Meaning, we can mount headers on both sides of the RPi board. Any help is appreciated.

Sean

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Imperf3kt
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Re: Through header -two-way - up/down - front/back

Wed Nov 20, 2019 1:21 am

You can't do that.
When attached from below, the pin order is inverse, you'd need to invert the connection on the hat you're attaching to use it on the bottom.

If you're extra careful to check the pins match, you could always use double length pins and jumper wires, but you'd also need to check that the two HATs you're using won't conflict.
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rpdom
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Re: Through header -two-way - up/down - front/back

Wed Nov 20, 2019 5:32 am

Imperf3kt wrote:
Wed Nov 20, 2019 1:21 am
but you'd also need to check that the two HATs you're using won't conflict.
If they are real HATs (follow the official HAT spec), then they will conflict (except for the PoE HAT, currently, as that uses a different i2c address).

Plain add-on boards may be used together, or even with a HAT, as long as the GPIOs used and any i2c addresses don't clash.

alphanumeric
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Re: Through header -two-way - up/down - front/back

Thu Nov 21, 2019 11:27 am

You can stack Hats and pHats, if one or more of them have a stacking header soldered in instead of the stock header. Female header on the bottom side and male pins on the top side. I've done it several times. As mentioned, if two or more have an ID eprom you'll have issues with them being auto detected by the OS.

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HawaiianPi
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Re: Through header -two-way - up/down - front/back

Thu Nov 21, 2019 1:17 pm

Imperf3kt wrote:
Wed Nov 20, 2019 1:21 am
You can't do that.
When attached from below, the pin order is inverse, you'd need to invert the connection on the hat you're attaching to use it on the bottom.
This ^ as Imperf3kt said, you can't just plug a HAT in upside down. That will not end well.

Something like this might help, assuming the HATs don't conflict (picture is link).
Image
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alphanumeric
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Re: Through header -two-way - up/down - front/back

Thu Nov 21, 2019 6:15 pm

If you put a female header on the bottom side of a Pi Zero, and a male header on the top of a pHat. The opposite of a normal setup. The pHat will plug in under the Zero. Pin 1 will line up with pin 1 etc.
Put a stacking header in the zero and you could mount another pHat or hat on top.
hat
female header
male header
zero
female header
male header
hat

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

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