blazini36 wrote: How is that going? I might be interested in doing something like this as well but eventually sticking the fpga directly on the PCB. It's just kind of difficult to figure out how to get started with the whole firmware thing. All I've done so far is write some bitfiles for MKSOCFPGA and spun them through the docker build that they have setup to get some firmware spit out.
Sticking on which pcb ? create a RPI hat you mean ? not really good, i already tried with an XC6SLX9 and the pb is the heat. I prefer have a good fan under the RPI4 than an FPGA hat. SLX16 and Artix are BGA package so its difficult to solder by hand.
The Hostmot2 firmware SPI can be ported to every xillinx FPGA younger than XC6, like all XC7 familly including Zync. The port of Hostmot2 on Vivado by Joseph Calderon was only tested in SPI but could work in ETH and PCI (untested).
The pb is that FPGA are expensive. an XC6 is enough for all linuxcnc applications.
The limitation is at 96 I/O maximum it could be very low for some specific applications, maybe we could find a way to reach 128 or 256 user I/O using some new FPGA like ARTIX 35K or 100K, or creating 2x HM2 firmware in a single FPGA if there is enough cells. it could be very easy and with a double SPI communication (SPI0 and SPI1) 2x96 = 192 I/O
