Dual sourced Digikey or Mouser

[richardeoin]

I built one of these a few months ago, and have successfully used it a couple of times since. It's a great project!

I made a few changes and called it "Rev0.2 R". Some of them may be interesting/useful. The main change was to dual source the BOM from Digikey/Mouser. There were a few part updates:

• Adjustable Reg -> AP3211KTR-G1 + Freewheel Diode
• Fixed Reg -> AP2120N-2.5TRG1
• 24MHz Crystal -> Epson TSX-3225
• 16MHz OSC -> ECS-3225MV
• USB Connector -> CUI UJ31-CH-31-SMT-TR
• RGB LED -> Cree CLMVC-FKA (not tested)
• pSRAM -> Can't quite be sourced, using IS62WVS5128FBLL instead

And one personal preference:

• Use 0402-size resistor banks

I've also been using KiCAD nightly, so reading the files may require a KiCAD newer than 5.99.0-1930-g59e265b42 (Jun 8 2020).

(Boards from AISLER B.V.)

[kbeckmann]

Nice to see someone else building a Pergola! Great to hear that it works as well.

I am afraid I can't merge your changes as I am still using the Stable version. I'll stick with stable for this project. Once the next version is released I might update the files.

I will include your dual sourcing of parts as long as the footprints and functionality match, but will do this manually. This is really useful so thanks for doing this.

Yeah, not sure why I chose 0603 for the resistor banks tbh. Will use 0402 in RevB.

If you haven't seen, there is a WIP RevB branch with planned changes. https://github.com/pergola-fpga/pergola/tree/revb_wip

Thanks again, but I'm afraid I can't merge this.

[kbeckmann]

By the way, if you haven't seen I have a repo with a bunch of examples and experiments over at my private github. Will clean this up and put it in the official repo later on. https://github.com/kbeckmann/pergola_projects

Also, I'm curious what you did for the firmware. Currently there are a lot of different options. In this repo's readme I mention a quick and dirty hack I made while bringing stuff up. However, I have done some work around this since.

If you want to use the Apollo firmware, you can do so by building a uf2 bootloader from https://github.com/pergola-fpga/tinyuf2 and flash it. You can even do so with the ROM-RAM bootloader.

Then you can flash the application, built from https://github.com/pergola-fpga/apollo/tree/pergola

I might have some wip changes checked in on those branches so I can't swear that it will work out of the box. But if you are curious, the code is all there.

[richardeoin]

Great 🎉 Thanks for all your work on Pergola and the examples.

The PR definitely isn't intended to be merged directly like for a software project, but I'm not quite sure how to express that on Github. It's more to make the ideas / "it works" story available. I've seen other hardware projects just leave the PR open (hopefully anyone sufficiently interested would find it) or merge it into a sub-folder called "contrib" or similar. Either works.

Iirc the fixed regulator, crystal and oscillator are pin compatible. The adjustable regulator is definitely not - it also requires an external diode. It might be worth considering that for a future revision: with an external diode there were several vendors to choose from whilst parts with the built-in diode were rare.

I wanted to play with project trellis / nMigen, so I went straight for the dirty hack :) It works, and it's sufficiently fast for enjoyable development. Luna is another good source of ideas/examples, as well as your pergola_projects, but I haven't tried the Apollo firmware. If I need or want to try something more than the dirty hack, I'll start there.

[kbeckmann]

Aha, that makes a lot of sense. Thanks for posting it, always nice to see what people do with your projects. I will try to pull in some of your changes anyway as they make sense.