Adapting microSD socket hinged type for Bee v2.0

On October 30, 2011 by sebastien.lelong

When I designed first versions of Bee, I mostly used Sparkfun Eagle library, as an habit, and browsed eBay on the other side in order to choose components: one that’s available in Eagle and cheap enough on eBay. By this time, I selected a microSD socket Push-Push type:

These were easily found on eBay, at a decent price, I ordered 5pcs (~$5). Since then, these aren’t available anymore, alternatives sources are much more expensive, something like $3 to $4 per socket. This somewhat kills my low cost approach… Another drawback is pins are under the case, which make this part hard to solder, probably the most difficult one.

Now I have few PCBs left, but no more microSD socket and only half complete kits.

Maybe another socket could be used ?

I recently bought this type: microSD socket with hinge (hinged typed). Price is even lower: ~0.5$/socket.

Good news: this kind of socket can be adapted to Bee v2.0 layout, with minimal changes. Here how it goes…

This is mostly about the two GND pins at the bottom. If you try to place this connector on the PCB, you’ll see these GND pins are very closed to the shield connector’s hole:

But…

  • interestingly, the bottom left pin is near GND connector ! Since socket case must be tied to GND, this pin can be soldered with GND hole without harm.
  • the bottom right pin is near C5 pin. Using PIC18F27J53, this pin is a USB pin and isn’t exposed to shield connector. Again, it can be soldered without harm. If using PIC18F25K22 (this is my case here), this pin is exposed as this MCU isn’t USB-capable. So the microSD GND pin must be cut in order to make sure it won’t touch to the shield connector.
  • on the upper side, another socket’s GND pin is near a GND pad. Can be soldered to it.
Here’s the result:
Notice the GND pin of the left is soldered within GND shield connector’s hole. The other bottom GND pin isn’t soldered as I’m using PIC18F25K22. It could have been soldered safely if using PIC18F27J53.
On the other side, one GND pin is soldered to one of the original microSD socket’s GND pad. The laft, fourth GND pin isn’t soldered at all. It’s a good idea to add some glue here to make sure the socket is firmly fixed to the PCB.
Note microSD SPI pins are clearly exposed when socket is opened, they can easily be soldered, at least much easier than using original Push-Push socket.

If you’re about trying this, don’t trust me and double check connections :) Give feedback as well.

And in the end, Push-Push socket will have to be replaced in another PCB batch.

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