15-05-2020, 12:22 PM
Which suggests there's something possibly fishy about the AliExpress one.
Don't rule out development boards. Modern FPGAs are a bit too complex and need too much support for most people to do development from scratch. I've done it from scratch since the early 1990s and have the scars to prove it. I would never do it again, either professionally or for my own purposes. For the odd one or two units then dev boards like the Arty are cheap enough. If you're going into production then you copy the relevant bits of the dev board design and layout as a first step. All newer FPGAs are in ball grid packages so DIY assembly is difficult. It can be done, google "bga prototype assembly" and you'll get a lot of hits. There's also the shed load of decouplers that need to be fitted to the other side of the PCB behind the chip. So even for small numbers I'd use a dev board for development and pay for manufacture if there's quantity involved. Possible halfway house like the original Hedghog is small FPGA dev board piggybacked on your own PCB. No different in principle to whacking a Raspberry Pi or other SBC on your own main PCB.
I know it means learning new dev tools but the Arty looks like the sweet spot for DIY. It's available through legit channels at a fair price. VHDL stays the same so a lot of things don't have to be re-learned when switching from Altera to Xilinx.
If the FPGA has dedicated CPU cores or can readily support them it's possible (though I'd be as much of a beginner as Frank) to have your MPU in the FPGA. Some dev boards have all of this built in. Haven't looked carefully at Arty for this. Then you can control the whole thing over ethernet from a PCat first. Then fit a physical front panel later if wanted.
Don't rule out development boards. Modern FPGAs are a bit too complex and need too much support for most people to do development from scratch. I've done it from scratch since the early 1990s and have the scars to prove it. I would never do it again, either professionally or for my own purposes. For the odd one or two units then dev boards like the Arty are cheap enough. If you're going into production then you copy the relevant bits of the dev board design and layout as a first step. All newer FPGAs are in ball grid packages so DIY assembly is difficult. It can be done, google "bga prototype assembly" and you'll get a lot of hits. There's also the shed load of decouplers that need to be fitted to the other side of the PCB behind the chip. So even for small numbers I'd use a dev board for development and pay for manufacture if there's quantity involved. Possible halfway house like the original Hedghog is small FPGA dev board piggybacked on your own PCB. No different in principle to whacking a Raspberry Pi or other SBC on your own main PCB.
I know it means learning new dev tools but the Arty looks like the sweet spot for DIY. It's available through legit channels at a fair price. VHDL stays the same so a lot of things don't have to be re-learned when switching from Altera to Xilinx.
If the FPGA has dedicated CPU cores or can readily support them it's possible (though I'd be as much of a beginner as Frank) to have your MPU in the FPGA. Some dev boards have all of this built in. Haven't looked carefully at Arty for this. Then you can control the whole thing over ethernet from a PCat first. Then fit a physical front panel later if wanted.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
