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geekhack Projects => Making Stuff Together! => Topic started by: ju6ju8Oo on Wed, 13 November 2019, 07:40:58

Title: TRRS Jack
Post by: ju6ju8Oo on Wed, 13 November 2019, 07:40:58

There're a lot of split keyboards using PJ-320A. Why isn't PJ-313B used instead?
If PJ-313B is used, the position of the TRRS Jack will be the same on both left hand and right hand.

Title: Re: TRRS Jack
Post by: piit79 on Wed, 13 November 2019, 08:21:09

Quote from: ju6ju8Oo on Wed, 13 November 2019, 07:40:58

If PJ-313B is used, the position of the TRRS Jack will be the same on both left hand and right hand.

What do you mean by that?

Title: Re: TRRS Jack
Post by: suicidal_orange on Wed, 13 November 2019, 19:29:41

Not sure what you mean about the position but PJ-313B is a 5 pole TRRRS connector and you only need 4 connections so that's one reason not to use it.

Ignore me, I'm too stupid to be trying to help at the moment :'(

Title: Re: TRRS Jack
Post by: ju6ju8Oo on Wed, 13 November 2019, 20:04:42

This should be a 4 pole connector?

Title: Re: TRRS Jack
Post by: ju6ju8Oo on Wed, 13 November 2019, 20:24:30

I think the 313B jack has a longer footprint, but it’s narrower (for flippable PCBs).
Another cool thing is symmetrical.

Title: Re: TRRS Jack
Post by: ju6ju8Oo on Wed, 13 November 2019, 22:17:09

Quote from: piit79 on Wed, 13 November 2019, 08:21:09

Quote from: ju6ju8Oo on Wed, 13 November 2019, 07:40:58

If PJ-313B is used, the position of the TRRS Jack will be the same on both left hand and right hand.

What do you mean by that?

please see the attached silks for PJ-320A [attach=1][attach=2]

If PJ-313B is used, the Y-offset can be avoided.

Title: Re: TRRS Jack
Post by: Findecanor on Thu, 14 November 2019, 00:30:51

I think it's just because of availability. I can't find this one at any larger component store when I search for it.

However, if designers of split keyboards would instead mirror and panelise their designs then having a symmetric connector wouldn't be an issue. A panelised PCB design might even be cheaper to produce if the halves have a weird shape that could interlock inside a rectangle.

BTW. The TRRS connector had been chosen because it is compact, which was important for a case of layered acrylic  when you want to use as few layers as possible. It is common for it to glitch, and you get noise if you turn it.
If split keyboard cases instead were made with tenting, there would be more vertical space under the raised side of each PCB for a more reliable connector: mini-DIN, 4p4c or even one of those aviation sockets that seem to be so popular right now...

Title: Re: TRRS Jack
Post by: ju6ju8Oo on Thu, 14 November 2019, 02:06:36

Quote from: Findecanor on Thu, 14 November 2019, 00:30:51

I think it's just because of availability. I can't find this one at any larger component store when I search for it.

You're right. There aren't many sellers who sell PJ-313B even on AliExpress.