This is the project I've been working on recently. Just assembled the first prototype. I've only populated 2 of the 8 analogue input sections, some values in filters may change and I don't need to waste expensive parts by building all 8 channels just yet. The signals go into an 8 channel simultaneous sampling 24 bit ADC which will run at about 256k samples per channel per second. The FPGA, an Altera MAX10M16, controls the ADC and does the heavy digital signal processing work. It has a little 128kbyte serial RAM from Microchip for extra buffering and talks to the uP via SPI and some handshake lines.

 

The processor (STM32F407) has an Ethernet interface connected via a Microchip PHY and USB connectivity via  an FTDI USB/serial converter.

 

I can't say what the two blocks of circuit driving the D connectors do.

 

The power supply stuff along the bottom edge is not populated for a sad reason - I checked up on part availability before I did the design but foolishly only tried to order the components once the layout was finished and the board ordered (so as to be as quick as possible). Alas, when I came to order the LT8640 chips that work the power supplies Farnell had sold out and offering delivery of more in December. No one else had any and I couldn't get a delivery date from any one else either. I ordered 25 form Farnell but they told me  a day later that LT had put the delivery date out to September 2018. I was rather expecting this and had already started work on a little PSU board that will piggy back on the main board where the 8640s were meant to be. The moral of all this is that you should secure the critical parts before you lay out the board - I've got too used to parts being readily available.

 

I'll try to find time to blog a bit about the Altera MAX 10s because they seem well suited to small volume applications. This one runs from a single 3.3V supply and has on chip flash so it's a lot easier on support chips than many other devices.

 

MK