[sdiy] FPGA

[Scott Gravenhorst]

The OP mentioned soldering/DIY so I thought I would mention my personal
modus operandi.  The larger FPGAs are packaged mainly in BGA packages which
are not all the easy to use for DIY boards.  However, my interest was not
in making my own PCB, it was in making a complex synth of my own design
with my own desired features.  

I was introduced to FPGAs when Jim Patchell showed me a Xilinx FPGA
development board at an SDIY meetup.  I bought a board of the same type
which had ADC/DAC parts already on it.  The board also had other things on
it that I don't use, but since development boards are subsidised by the
chip mfr to one degree or another, one can get a good deal on a
premanufactured board that has already been troubleshot.  I now have 7
boards of different types ranging in price from $50 to $300.  Using the
least expensive of these which has the smallest FPGA in my collection (400K
gates), I was able to design at least one 16 voice polyphonic synthesizer
which included an embedded soft microcontroller for MIDI.  These boards may
or may not have DAC/ADC hardware on them, buy some or many do and those
that do not can usually have these connected externally.

For me, the DIY is not so much in the soldering, but in the design and
coding work, so using a prebuilt dev board was fine for me - and eliminates
the troubleshooting of lower level functions such as getting a bit-file
into the FPGA.  With a dev board, I'm able to start coding the day I get it.

-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
-- FPGA MIDI Synthesizer Information: home1.gte.net/res0658s/FPGA_synth/
-- FatMan: home1.gte.net/res0658s/fatman/
-- NonFatMan: home1.gte.net/res0658s/electronics/
-- When the going gets tough, the tough use the command line.