FreeCalypso HQ has some stock of our two models of GSM MS development board: FCDEV3B and Caramel2. If you are interested in getting one of these boards, there are two potential ways how you may be able to do so:
General availability: if you are able and willing to pay a price that makes sense for our economic situation (we are based in USA, and more specifically in one of the highest cost of living areas within this country), anyone can buy the hardware by simply paying that fair market price, with no extra questions asked.
Unicorn subsidy program: if you fulfill some very special and strict requirements, you may be able to get a FreeCalypso board either completely free of cost or at a very steep subsidy. Please see the linked page for more information about the unicorn subsidy program.
If you do not qualify for the unicorn subsidy program linked above, or if your personal beliefs and values are incompatible with those required by that program, and you wish to purchase a FreeCalypso GSM MS development board on general availability terms, the current prices as of 2026 are as follows:
FCDEV3B is a devboard of much higher quality than Caramel2, but we have extremely few boards left that are completely free of defects. This low inventory status is the reason for the very high price: we have to set the price high enough so that if we sell all of our remaining boards, we would get enough money from those sales to produce another batch.
On the other hand, Caramel2 is a cheaper FreeCalypso devboard that did not turn out as good, and an argument can be made that this board should have never been produced in the first place, had we been in a better political situation in year 2020. Because this design did not turn out very well, we don't plan on making any more of them once we clear out stock — and because we do wish to clear out this stock, we are selling them at a much lower price than FCDEV3B. However, we still need to set a non-trivial price even for Caramel2, so that when we sell off these boards, we would get enough money to produce either a new batch of the higher-quality FCDEV3B or the currently hypothetical EvaTango board, a more proper successor to Caramel2.
In both cases (FCDEV3B and Caramel2), the price listed on this page includes the complete set of accessories beyond the main GSM MS devboard:
FCDEV3B and Caramel2 feature different analog audio interfaces, which come into play when the developer-operator wishes to exercise GSM voice calls or Calypso DSP audio functions:
Caramel2 has a 2.5 mm TRRS audio jack whose pinout has been copied from iWOW DSK board — it is not the same pinout as Motorola C1xx and Pirelli DP-L10 headset jacks that have the same mechanics! We had our own FC-HDS4 headset custom-made in this wiring; we have enough of these headsets to include one with every Caramel2 kit.
FCDEV3B has a loudspeaker amplifier circuit copied from TI Leonardo; it drives an 8 ohm loudspeaker and the output is on a 2-post header. There is another 2-post header to which one can connect an electret condenser microphone, also following Leonardo schematics.
We can supply loudspeaker and microphone accessories for FCDEV3B if requested — however, because we may not have them in stock, there may be additional lead time to assemble them.
If you are interested in buying one of our GSM MS devboard kits, please email Mother Mychaela.