Not yet, but I finally got around to finishing the board and sending it off to JLC last week.I really like the Tang boards as the Tools are very quick and simple to use. I’ve just ordered a Tang Nano 20K.
BTW Dave have you tested your Tang Nano 20K expansion board yet. It looks very useful
Here's a sneak preview:It's grown quite a bit!
I ended up switching from through-hole to "chunky" SMT (0.05" pitch SOIC for the ICs and 1206 sized discretes). Everthing is well spaced out, so this shouldn't be too difficult to hand solder:The main compromise, due to the limited number of I/O pins, is that you can't have both the VGA port and the external PiTubeDirect Co Pro active at the same time (there will be different FPGA bitstreams for each).
The VGA port supports 4-bit NuLA RGB colour using some amazing FPGA-based 1-bit video DACs courtesy of Dominic Beesley. These benefit from a decent analog filter, hence all the L/C/R components sat in from of the VGA port.
There are lots of choices for audio:
- HDMI (much better quality now I've added a proper mixer / sample rate converter)
- analog line out (3.5mm connector) (using either an external 24-bit DAC or a FPGA based 1-bit DAC)
- digital S/PDIF (phono connector)
- digital optical (TosLink connector)
- class-D amplifier on board the FPGA which will drive a speaker directly
All of these can be active at the same time.
The four ICs are:
- a TXS0104E level shifter for the PS/2 keyboard / mouse
- a pair of 74LV165A 8-bit shift registers, for the joysticks and config jumpers (this only consumes two dedicated FPGA pins)
- a CS4354-CSZ 24-bit DAC for the line out audio - optional as the DAC is quite expensive (about £6)
Expect an update in a week or two when we get boards back.
Dave
Statistics: Posted by hoglet — Wed May 07, 2025 2:30 pm