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Pico Pi Castellated connection
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Pico Pi Castellated connection

by dresch on Sun Nov 07, 2021 8:17 am

Castellated.JPG
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For ESP32 modules with castellated edge connections, development boards like this are available:

https://usa.banggood.com/ESP32-Test-Boa ... 3EEALw_wcB

Is there anything like this available for the castellated side connections for a Pico Pi? I would love to build one if there is a source for the bent spring clips. Often I would like to test things on the Pico Pi before committing to what kinds of connections to make...
Any suggestions would be appreciated.

Thanks,
Bill
dresch
 
Posts: 9
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Re: Pico Pi Castellated connection

by mikeysklar on Tue Nov 09, 2021 6:53 pm

Bill,

Seems like a good idea to make a castellated Pico Pro project.

We do not sell any at this time. The closest I’ve seen is the “Hammer Header” which looks like an easy design to use no solder pins with the Pico.

https://vilros.com/products/hammer-head ... ry-pi-pico

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mikeysklar
 
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Re: Pico Pi Castellated connection

by dresch on Wed Nov 10, 2021 6:56 am

Thanks!
That certainly seems like it would cut down on rosin fumes but yikes-amighty, hitting near a BGA chip bearing surface with a hammer scares the bejezus out of me.
In our factory we are used to seeing field failures from board flexing with chips breaking internally or connections fracturing. Hopefully that is all tuned in and accounted for with this jig and the hammer induced stresses are small.

On the ESP32 castellated board, the contacts appear to be phosphor bronze wires bent in an exaggerated fishhook shape. The long arm passes thru a slot in the PCB that keeps it aligned in the axis it would be spread out in and the tip of the hook is soldered to a via in the board.

Perhaps it is time to build one of these:
https://www.youtube.com/watch?v=HPQbKTJPsU4
https://howtomechatronics.com/projects/ ... g-machine/

for some phosphor bronze fingers.
And wire is available:
https://www.etsy.com/market/phosphor_bronze_wire
(Or just harvest all the little phosphor bronze fingers from the ESP_WROVER burn-in board and build with them:
https://www.aliexpress.com/item/1005002 ... d5b18663b4)

I have seen this kind of castellated connector design on demo boards for bluetooth modules also.

Or perhaps just 2 of these mounted as a V to each other and a small mechanism to press the Pico Pi into the V.
https://www.peconnectors.com/machined-p ... 0/hws9395/

Thanks again, Bill
dresch
 
Posts: 9
Joined: Mon Feb 06, 2012 8:53 pm

Re: Pico Pi Castellated connection

by mikeysklar on Wed Nov 10, 2021 7:15 pm

Bill,

I like the last link the best using a V mount or a simple 3D print jig to align the pins against the sides of the Pico.

mikeysklar
 
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Re: Pico Pi Castellated connection

by dresch on Wed Nov 10, 2021 8:11 pm

Just have to talk myself into the $30 minimum order...
Thanks again for your replies. If I get something working I will post it.
Bill
dresch
 
Posts: 9
Joined: Mon Feb 06, 2012 8:53 pm

Re: Pico Pi Castellated connection

by mikeysklar on Thu Nov 11, 2021 2:21 pm

Cool. Curious to see what you come up with. Last night the idea of using male machined pin headers came to me. They are equal height on both size and thinner so they could be used with the Pico castellated edges.

36-pin Swiss Male Plug Headers - Pack of 5
https://www.adafruit.com/product/3647

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Please be positive and constructive with your questions and comments.