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[on:]

I'm trying to cram as much stuff on a 0.8x1.3" board that will send messages to 1-4 SURE 3208 displays.  So far, I've got around 11x13mm available on the top to play with, seen in the upper left of the image below:


I need something that preferably takes no slow-clock input, minimal caps, etc.

Some of the items here might work:http://www.alibaba.com/member/kr1015760380/productlist.html but they're minimum qty to order is 2000.  I need one or two.
Then I found these from panasonic:http://www.digikey.com/scripts/DkSearch/dksus.dll?lang=en&keywords=P14961CT-ND&WT.z_slp_buy=Panasonic_Bluetooth&cur=USD  They might work, but I need an external crystal, plus a 3v3 regulator and a few other parts, which I suppose I could put on the back side.   Bluetooth 2.0 or 3.0 doesn't matter so much as it will be using a minimum of receiving, but I can't seem to find much else that is small enough, yet easy to use...even the LMX9838's are 10x17 or so.  Do any modules exist that fit these requirements and are easy to integrate?


EDIT: Actually the LMX9838 might work, but not sure how easy it is to use.   Found this:


that doesn't show an external crystal...so perhaps i can fit it in

[Reply #1 on:]

So you only have to find 4mm at the side of your space, you could pack that board much tighter yet, and move the four Tx/Rx components. That would give enough space.

Is that a mini B jack? If so use a micro B.

How often will you use the 2x3 header? With offset holes it looks like it's designed to hold a header just for bootloader programming, use something smaller or have 3 pads on each side of the board and slide a header from the side.

______
Rob

[Reply #2 on:]

So you only have to find 4mm at the side of your space, you could pack that board much tighter yet, and move the four Tx/Rx components. That would give enough space.

Is that a mini B jack? If so use a micro B.

How often will you use the 2x3 header? With offset holes it looks like it's designed to hold a header just for bootloader programming, use something smaller or have 3 pads on each side of the board and slide a header from the side.

The 2x3 header won't be populated,  I used an offset (sparkfun library) to make it easier to insert programmer first time (touches pads better)
The USB header is one of the smallest micro usb jacks I've found.  I went with a partial through hole component due to the first revision of the board using a part with solder pads (the connector ripped off the board, taking the pads with it) after a few insertions.

I actually had an idea while I couldn't sleep last night, and that was to go to a smt 16 pin header that mounts to the bottom only, thus freeing up the entire top part of the board.   I kind of wanted to stay away from having to solder stuff to two sides, but I suppose i can create a second stencil to paste the back and then hot-air the connector on.

How often will you use the 2x3 header? With offset holes it looks like it's designed to hold a header just for bootloader programming, use something smaller or have 3 pads on each side of the board and slide a header from the side.

This is a fantastic idea!.  Never thought about changing the ICSP header to a slide on prgramming adapter or building a breakout adapter and using a smaller pitch connector.

I'm trying to pack everything closer together each time i run over the board, but I'm open sourcing this once it's done on github (and hear) since 3208 displays are so popular around here, and wanted to try to make this easy for others to assemble who may not have hotair tools or steady hands

Thanks for the tips!

______
Rob