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Mathias K. kesmtp at freenet.deOn 11.07.2012 10:26, Harald Welte wrote: > the core modem design is 40 x 29.8mm in size, but that of course > excludes things like the sim card reader, or any other new components we > may add. So it looks like the MiniPCI Express Card on this picture http://en.wikipedia.org/wiki/File:MiniPCI_and_MiniPCI_Express_cards.jpg ? > After some first checking, that size would actually even fit nicely > within the mechanical form factor of the C1xx boards, as they have at > least something like 36 x 70 mm mechanical form-factor. The question is, if you want to build a modem or re-engineer a phone for cases that: > There are some signs that the supply of Motola C1xx phones is not > endless, after all. And this include the cases as well. > Now if thre was an _easy_ way to make one circuit board that would both > fit into the C1xx case _and_ also have a board edge connector for use in > a back-plane, I would consider doing that. Make it simple. > my first idea is to have a 'break away' backplane connector that one > would simply break off to mount it in a phone case. But then, if it is > intended to be broken (e.g. by perforating with a series of holes), the > PCB might break when it is plugged into the backplane and somebody > pushes it sidewise. The 'break away' connectors came from manufacturing and they are not made to use it on "harsh" environments. >>> * expose JTAG >> >> 1.27mm 10 pol Pin-Header on the opposite side of the board edge >> connector, this make it possible to debug the board in a backplane > > yes, good point. However, on that side there is likely the RF > transceiver and the antenna connections :( You probably don't want the > transmitter near the jtag cable... For development that's fine i think. But this is related to the planed backplane connector. > >>> * board-edge connector for plugging many boards into one backplane >> >> I would suggest the ERNI SMC. There are also a cable assembly available. >> http://www.erni.com/fileadmin/medien/downloadcenter/smc/ERNI-SMC-e.pdf > > undoubful great connectors, but I really wanted to keep it low cost, > thus the proposalf of using PCIe connectors on the backplane. Needs no > connector on the board itself, just a bit of board footprint. Yes but that's only simple on one site and the board price increase because the extra milling ways but maybe for a 6 plane pcb it's not that much. I think the initial hurdle to get it run on the table is really high with this kind of connector. How a developer or backplane board should looks like and whats the estimated price relative to the modem price? Regards, Mathias