New Fairphone 2 Bottom Module with an appropriate case

For reference: New Fairphone Bottom module with USB-C port

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The New PCBs arrived and I have soldered one of them and it is working way better than the old one the connector is a relly good molex one.
There are some minor issues, but I’ll fix those and test some more and then also send some pictures of the module.
I will also do some minor changes to the housing

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Here are some pictures.
I had for some unknown reason trouble with the mic I ordered, switched it out and it works perfecly. All of the other stuff including the USB-C connector worked perfectly the first time I tried.

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The PCBs are so gorgeous ! Great work Leo !!

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Great work, @Leo_TheCrafter! I hope one day in the future, when the FP2 runs out of support, the module specifications of all modules will be published by Fairphone as open source! (just dreaming)

Btw. I’m still interested in buying one of your new modules!

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Here are some technical changes I made:

  • Slimmer fuse

  • Routed USB +/- as diffferential pair with propper track length matching

  • Better USB connector (MOLEX 105450)

  • Propper USB power line filtering with ferrite beads

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My microphone breaks very often. Is that better with this “alternative module”? Does it fit into the standard slim case?

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No, You need a special case, but I’ve never had a mic break.
There were some contact problems with the older revisions, but those are fixed due to newer and better meassurements of the connector.
For the case I have a printed case out of TPU, flxible plastic.
It is not only a alternative, but also gives you USB-C

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I guess that is because the microphone’s position at the bottom side is different and the USB-C port has a different shape that the case needs to leave accessible as well, right?

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Yes that’s the reason.
You can carve out an old case, but it’s not reccomended, because then the connector can’t be propperly supported and the port might wear out quickly

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I wonder if mics damage due to water, and I wonder if you could mod the case to have the mic working with the old case.

My old case is on the way out, only thing with Leo’s C-case if that it is difficult to apply/remove and there is going to be dirt under the edges and corners because there is room under the screen and the case on the edges and corners.

I actually plan to do a differnet approach with the case soon, made out of solid PLA, but there’s some prototyping and design involved, that just takes it’s time

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Good point, I was wondering if the TPU case would be rigid enough to keep the battery in place.

I’ve never had an issue with that (restart due to loose connection was a concern), but I fell like the USB-C connector is still not enough supported.
You can get rid of dust with canned air pretty easily, but still this problem needs to be adressed as well

When do you think the new case is available?

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Am currently printing very early concepts to find out how to do this, but it’ll probably take some more days or weeks before I’m satisfied with the results, I will keep posting here

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I’ve finally finnished a new case, which is made out of solid material, PLA in this case (pun not intended).
It is made up of two pieces and they are held together very firmly by friction. It still is kinda brittle, so I’ll try printing a new version out of ABS, a very though industrial thermoplastic, which also has a higher usable temperature of ~80°C. I’ve experienced that PLA can deform under heavy workloads like gaming, when the CPU gets hot.

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??

Is this just in your new design or does the original module also keeps a fuse?
This then could also be a cause if bottom modules stop charging. I never took a close look at the original pcb design. I assume it’s a smd chip format.
Btw. what’s the fuse rating?

You are doing a great job Leo. :+1:

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The new one also has a fuse, made by littlefuse (https://lcsc.com/product-detail/Surface-Mount-Fuses_Littelfuse_1812L200THPR_Littelfuse-1812L200THPR_C207074.html)
It is a reset fuse, that heats up in case of a short and when it cools back down it resets.
The rating is 2A hold and 3,5A trip with a maximum delay of 2s, so it’s rather slow, but also doesn’t blow at small spikes of current.

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Sorry, maybe a partially missunderstood what you tried to ask.
The original module by fairphone does not have a fuse, but I decided to include one in mine, because soldering errors, dust or user error could short the power supply and I wanted that extra bit of safety. It does not interfer with the voltage or the maximum current of the charger

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