Custom Shield - MicroSD/FRAM

Just want to say that my resources are all channeled for Local :cloud: and this is currently on hold.

If you are still interested to get a few in future, complete the survey here:

Today, i saw that a microSD breakout board from Sparkfun costs USD10.00.

I believe this shield has the potential to be priced at that range with much better capabilities :wink:

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Almost done with the DFM refinement and working on the BOM now.

Bottom Silkscreen:

Top Silkscreen:

Top routing:

Bottom routing:

Pre-orders will be taken soon :smile:

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is the ground plane still connected in the lower part? it looks isolated near the solder jumper 4 now

looking great though, cant wait to test it out!

It’s deliberately left out (adviced by @BDub) so that the Wifi signal does not get cranky if someone decides to solder it directly to the core :smiley:

i understand the clear section right at the bottom where the chip antenna could be effected, but right next to SJ4 it looks like there is a little gap and i cant see what connects the 4 vias in the lower ground plane to ground

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OHHHHHHHHHHH!

Good catch @Hootie81, got affected when i shifted the vias on top.

Some top copper probably pulled ground to one of the via and fed the ground below.

But i will fix it right after i come back from my run :wink:

UPDATE

Fixed! Thanks @Hootie81! I really appreciate that. Such mistakes are expensive :stuck_out_tongue:

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Tweak! I would push that decoupling cap a little closer, because you can :wink:

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DFMMMMMMMM bro DFM :smiley:

I know i can. BUT the solder iron (because the :spark: core is awesomely tiny) will burn stuff when you perform repairs on failed boards.

Ok, but then this is not too close because it’s just a piece of metal?

BTW: if you did slide the cap up and the soldering iron “they” use would touch both the cap and FRAM, they are using the wrong soldering iron for SMT! :smile:

Also then, these two components would be too close:

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Thanks for the feedback man!

I think for the 1st portion, the top portion is microSD socket and will not move so it’s fine. Just need to avoid the header on the side!

It’s going to be easy to burn the black plastic when the solder iron gets to closeee.

Honestly… That Resistor is super tough to place :stuck_out_tongue

For the 2nd feedback, I can probably move the LED slightly more to the left.

Thanks guys! :smiley: :smiley: :smiley:


@BDub, is this better?

Well that resistor was ok where it was in my opinion :wink: It just matters what your Contract Manufacturer’s DFM policies are. I was questioning what your requirements where. Do they have a minimum keep out area around all SMT components for soldering tools? That said, moving the resistor over isn’t going to hurt. Ship it! :slight_smile:

:heart: I’m not sure if @will have shipped to you guys yet.

On a sidenote, do you think it’s possible to expose the FRAM on DFU?

I’m probably the “Contract Manufacturer” for Batch 01. :stuck_out_tongue:

Currently checking out prices from Shenzhen to bring down the FRAM price further!!!

Since the sFlash is exposed, I don't see why not :wink: It would just need an interface like the sFlash has, and a memory mapped location. It might lock you into a certain memory size though if this was added to the Bootloader... not sure if "that" is really possible though.

If you are thinking of a quick way to program the FRAM, and you are going to read from a file anyway, why not write an application that reads the file from the Micro SD card, and writes it to FRAM :wink: Then you have total control. The application could also look for a file on the SD card every time it powers up, and if present, load it into FRAM. Then optionally it could delete the file so it doesn't do this every time you power up. This way you could easily update your FRAM memory with a SD card swap.

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Yep can totally see how hard it would be to re-solder anything close to those header pins. i remember making boards 10 years ago and there was a resistor and a cap wedged between a L297 SO20 and L298 multiwatt that were a pain in the bum to get at! we ended up making our own soldering tips by welding copper bar onto an old tip shaping it to a useable shape that got in there easily and then dipping the end in some nasty chemical stuff so that it coated it.

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Gearing up for pre-orders :smile:

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ohhhhhhhhhhhh. Bummer. Crowdtilt.com requires a US bank account :stuck_out_tongue:

Time for bed and search for alternatives in the morning :smiley:

Hello folks,

Time for pre-orders! Let’s Rock & Roll :smiley: :dancer:

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Hello @kennethlimcp,

Tried to pre-order but the site says your campaign is in sandbox mode. Is this the way you wanted it to be ?

Yes, we are on Pre-order and will not require your credit card info.

Sorry for the confusion :slight_smile:

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Ordered! Thanks Kenneth!

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