Osmocom GPS timing source with u-blox LEA6-T
Recently we have been looking for an inexpensive way to generate a high-accuracy clock source for E1 lines, as it is required by a number of classic BTSs that don't have a sufficiently accurate OCXO built-in.
Luckily, the Digium E1 cards like TE-410P have a timing connector, to which an 8.192 MHz signal can be injected. Unfortunately, there don't seem to be any OCXOs around for that frequency. That's where the u-blox LEA-6T comes into play: It has a configurable TIMEPULSE2 output that can generate any frequency up to 10 MHz. We use this in our board to generate 8.192 Mhz and want to feed that into the Digium card.
So all we had to do is build a small board that contains the module and connector for antenna input, clock output and the obligatory 2.5mm stereo jack for the OsmocomBB-style UART:
Thanks to Sylvain for doing the schematics/PCB design, and thanks to Pablo for writing the code to configurea and activate the 8.192MHz output.
Once the design is verified, the schematics + gerber will be available, as well as board from the sysmocom webshop.