Custom calypso board

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Harald Welte laforge at
Tue Jul 10 17:00:19 UTC 2012

Hi all!

There are some signs that the supply of Motola C1xx phones is not
endless, after all.

As such, sysmocom has decided to manufacture some custom boards with the
typical TI Calypso/Iota/Rita design.  The RF PA will be RFMD RF3166, and
the combined NOR + SRAM will be a Samsung K5A3281.  All parts are
still available from the surplus market.

Schematics will be published in PDF form only, Gerber/PCB files will not
be released (so basically the same like the OsmoSDR situation).  All
software used is already available as OsmocomBB under a *GPL license.
Any help and input from the community will of course be appreciated.

The design will be more or less a standard tri-band calypso phone design
(900/1800/1900), with possibly a placement option for having
850/1800/1900.  We'll be targetting a modem as opposed to a phone
design, so no built-in keypad / display / battery, but external

At one edge there should be a PCB edge connector, possibly with
mechanical form-factor of PCIe (sinc they're cheap).   This connector
should allow the module to be plugged into a back-plane with a number of
other modems.

I've crated an initial Wiki page about the possible / intended
modifications from a classic phoned design at :

 * expose JTAG
 * board-edge connector for plugging many boards into one backplane
 * external clock input / buffered clock output
 * RF connector standard u.fl or SMA or optionally separate Rx/Tx?
 * I2C/SPI and both UARTs available on headers
 * on-board EEPROM for storing persistent data, even beyond NOR flashing
 * SIM card slot, SIM interface also present on header
 * additional / unused TPU ports
 * header for TSP / TPU and all data/control interfaces between iota/rita/calypso
 * RTC crystal and footprint for lithium backup battery
 * version of the board with uplink / downlink filters switched

Feel free to discuss other extensions/modifications you may have in
mind.  Please note that fundamentally we are still heading for a calypso
based design, so this will not be a board that just contains the
Iota/Rita and some FPGA or general purpose DSP, as some people have
proposed in the past.  However, it may be possible to have connector
footprints for the TSP / BSP interfaces and make some boarde that don't
contain the calypso/ram/nor parts.

Pricing will definitely not be anywhere near to the price of current
phones.  You cannot even source all the components for the price of
those refurbished phones, let alone the fairly complex 6-layer PCB.
Also, the quantities will be low, we may be manufacturing something like
100 units a batch only.

This is a low-effort / side project, so I'm conservative with any
estimates and would say that we're happy to have boards shipping by the
end of this year.

	Harald (waiting for the e-mail flood)
- Harald Welte <laforge at> 
"Privacy in residential applications is a desirable marketing option."
                                                  (ETSI EN 300 175-7 Ch. A6)

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