- 30 pin Apple dock connector (left bottom): best solution, but due to its large footprint it gives a rather large board when combined with a patch antenna. The prototype II board combined this connector with a chip antenna while providing a small board size, but the performance of the chip antenna turned out not to be as good as a patch antenna.
- 10 pin I/O connector (left top): next best thing considering it has 10 pins and allows routing of other signals besides the 4 and 5 pin USB connectors. However, there are no standard cables around that can plug into this connector and they would have to be custom molded.
- 4 pin mini USB (second column from left): this is the connector I used on the prototype I boards. It has the smallest footprint among the mini USB series connectors.
- 5 pin mini USB connectors (third column): this connector is the most commonly used on the mobile equipment of the recent past. It comes in different form factors (see photo from top to bottom): midway mount, bottom mount, top mount. It has a larger form factor then the 4 pin USB.
- 5 pin micro USB-B connectors (most right column):this connector is the new standard for current and future mobile equipment and has quite a lot smaller footprint than the mini USB connectors. It comes in multiple form factors, two of which are shown in the photo: midway mount, top mount.
Regarding the mini USB cables, these are readily available these days from various places: 4 and 5 pin mini USB at Amazon, various USB connectors at Pricewatch, or just Google for mini USB.
The micro USB cables are a little more recent, but you can also get them from Amazon for $2, or from Walmart for $5.
So I don't really think it matters too much from an availability/cost standpoint what connector we choose. I might even make the cable available with the module. More important are other factors like footprint and height on the PCB.
As such, I have set the top-mount micro USB connector as the device of record (DOR) as it has the smallest footprint and lowest profile.
In the meantime, I will keep an eye out for any other low-profile multi-pin connectors that are around.
Feel free to post any more comments you have on the subject.