Input connector shim - for power switch, USB 2.0 and LEDs

Heyo! I’ve developed and now tested this nifty board that lets you attach an external power button to a Framework mobo, as well as exposes a USB 2.0 port and backlight/fingerprint/capslock LED connections. I sell these, and you can also order the PCBs and assemble one yourself, just needs a kapton tape fix before reflow. Hope this can help!


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This is great to see. In a future version it could be interesting to have a footprint for an RGW LED and tact switch directly on the board as a replacement for the power button, or alternately a connector for the Framework Laptop Fingerprint Module. The interface for the Fingerprint Module is:

Uses Kyocera 046809610110846+.

Pin Signal Notes Voltage
1 VBUS Power 5V
2 USB_DM USB Data
3 USB_DP USB Data
4 GND Power
5 EC_CONTROL Output - mask switch events
6 SWITCH Open collector output
7 LED_W
8 LED_G
9 LED_R
10 LED_COM
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Oh thank you, this is a pleasant surprise - we’ve been looking into REing this connector just a few days ago!

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This info and project is super useful! :heart: being able to use the non-USB-C connectors for their original purpose really expands what you can do with the mobo on it’s own!

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This is great! Ordered.

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Any idea on if youll be selling any more of these?

Restocked them! Thank you for the reminder, forgot I had an assembled batch I needed to punch into Tindie’s interface.

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Would it be possible to get the battery level as well? I was thinking something similar to how the old macs if you press the side button will show green LED’s that represent the current battery level.

Looking back at it,

Is there any particular reason why this is not made as a piece of FPC?
It’s just a surface-mount-connector to a bunch of pads/pins

Granted, FPCs don’t have a track record of being anywhere reliable, but so is flimsy wires soldered to a PCB.

There’s no benefit to having this board as an FPC, and a lot of drawbacks. For instance, unplugging the shim from the Mainboard could tear the FPC. That said, you can already take the shim PCB files from GitHub and order them as an FPC from OSHPark, if you so desire!

As for wire flimsiness - you choose the wires that you solder to the shim and the way you fasten them, you can replace the wires at any time, and so far, the shims themselves have held up pretty well. In particular, having wire contact points as through-holes is a feature added to reinforce the wire contact points. even if it makes it harder for me to solder these shims.

All in all, regular wires will hold up pretty well in majority of situations with these PCBs - the shims and the wires attached aren’t meant to be moved often, after all. If they were, I’d be designing them in a different way - there’s pretty foolproof ways to attach wires to a PCB, but those would result in the shims becoming unnecessarily large otherwise. If you need more resillience to the point you never risk a wire breaking off, add hot glue and tape to your liking!

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I could add a bit of extra optional hardware, but then you’d need to modify the EC firmware a tiny bit :wink: Which, you absolutely could, given it’s open-source and everything!

yeah I figured.

The one reason I said “FPC” is because my Dell XPS L321X have this


And I thought "hey this is a really great low-profile- way to extend a bunch of pins to somewhere else that’s actually needed.

This is inferior to FPC connectors (the flap-down ones) on the PCB; this is evident in the fact that this ribbon cable broke once; this is a replacement. But also, consider how many times I have taken this apart, I think it’s a great solution. But, as you can see, there are black plastic backings strengthening the area close to the connector, and I have no idea how that works.

Price out how much a custom FPC like that would cost in small quantities, even without the stiffener plate. Companies like Dell can get deals due to the absolutely huge volumes they do.

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Is there any chance there will be a restock soon? This looks absolutely perfect for what I am looking to do.

Just thought I might as well make a design for something similar, so I have designed a prototype with a tactile switch to turn on the laptop and a ZIF connector for the fingerprint module, along with 2.54mm headers if you decide to not use the fingerprint module.

https://buy.stripe.com/aEU8xybLs3dsbegeVa

Is anyone here able to tell me the value the 5v select resistor should be? I can’t work it out from the documentation provided by @Arya nor the KiCad files.

Edit… never mind. Just realised 0R means ‘0Ohm’.

Just use a solder jumper.

Yea, I have done. I was reading ‘0R’ as ‘OR’ and was getting confused - very much an amateur when it comes to electronics!

On my third attempt at getting the connector to sit properly at the moment.

I’m not sure I agree with the OP that through hole is the best choice for this board. I think the risk of pulling off a smd pad is very low in this kinda application and the trade off is using kapton tape which holds the connector ever so slightly off the board - which I think is making my attempts to solder it harder.

I’m also not very good at it… But I think if I order a new batch of these PCBs I’ll do it without the through hole.

Just trying to work something out.

Is the RLim resistor necessary to stop the LED getting too much current and thus burning out, or to prevent the LED pulling too much current from the connector?

Basically wondering if I have a power button with internal LED that can be run from 5v directly if the Rlim is necessary.