Jim Kleiner created a minimal FPGA cape for the BeagleBone Black:
BBB LX9 FPGA Board
Jim describes his design decisions:
I decided to try a minimalist hand solderable FPGA board. The LX9 is the largest part available in a TQG-144, beyond that its BGAs
One of the key points is that the SPI interface is on BBB pins which are accessible via PRU0. This is important since the PRUs can be used to obtain higher performance SPI interfaces than the built in hardware units (examples here, here, and here).
The KiCad desgin files are available on GitHub:
drone32768/BREC
The overall cost sourcing from OSHPark and Digikey is $12 for the PCB (quantity 3), LX9 $18 (quantity 1), connectors $3, oscillators, and regulators $3, Flash and passives $3 for a rough total of $39 per board.
KiCad design files are available on GitHub:
BREC_3/Boards/Fboard
KD2BOA has shared the board on OSH Park:
How did you manage to hand-solder that thing onto the board? It looks like quite a challenge to me!
Ideal for a board like this is to use a stencil and solder paste and then reflow with hot air or a toaster oven: http://hackaday.com/2016/06/02/tools-of-the-trade-reflow/
Need a link to the OSHPark board if available.
I can’t seem to find on the website, but I’ve made a comment on the designers blog asking if there is a link to OSH Park.
KiCad files are available at:
https://github.com/drone32768/BREC/tree/master/BREC_3/Boards/Fboard
The OSH Park project is also shared at:
https://oshpark.com/profiles/KD2BOA