Fates - a DIY norns DAC board for Raspberry Pi

Maybe? At the moment only if you can do SMD soldering (0805 passives and a SSOP28 chip, along with some tiny pins on the USB-C connector), and if you’re good with Raspi Linux stuff. Documentation is still a bit lacking (i.e. no build guide yet, etc.).

I have boards going out this week to a couple people for testing so I was gonna see how that goes first.

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SMD is no problem (built a ton of SMD modules including an arc with 256 SMD LEDs :grinning:). Also have a pi and Linux is fine… I have a scope and logic analyzer too

Would be interesting if you could write a few words about the noise issues and how you solved it.

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In regards to potential beta testing and refining instructions and documentation, I’d be happy to help. I have now built a functional Norns with your instructions, with all proper parts. Not to mention, I made every f%#^*ng mistake possible in the software build process so My experience can help flesh out some areas for people with moderate Linux knowledge.

Plus, considering all the help you kindly gave during my struggles, I’d appreciate the opportunity to give back.

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Hey… thanks for the offer. For the moment I’m going to do a closed “beta” of sorts with a few people and see how that goes.

Hopefully the new install scripts I’ve got will make the Linux portion of all this much more simple.

Mostly this comes down to pcb layout issues wtih interference between digital control signals and analog audio signals. Apparently there is a certian amount of art/voodoo to doing good pcb design and I’ve been slowly learning by making lots of mistakes. :slight_smile:

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So any tips what to avoid? Or is it difficult to make general statements?

Maybe something like “Don’t cross the streams” :grin:

That is to say - keep your digital and analog signal paths separate (not crossing over each other) as best you can.

Full disclosure - I’m a novice at all this and have no electrical engineering background. I’m just learning by doing. And I’ve learned audio boards are kinda hard.

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I’m building my own DIY instrument (not a norns clone) and have another technical question, if I may, is the display SPI or I2C? Does it share I2C connection with the audio chip? Any issues with this?

I’m looking at the WM8960 Which I suspect will have similar performance.

I have also read to use separate analog and digital grounds, and to connect them only at a single point…

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The Newhaven display uses the SPI gpio. I2c is reserved for audio here. No conflict between the two.

also FWIW - the RasPi 4 has like…

I/O:… up to 6 × I2C, up to 6 × UART (muxed with I2C), up to 6 × SPI (only five exposed on Raspberry Pi 4B)

So you could work it so nothing in shared pretty easy.

I did exactly this in the most recent version.

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Thanks, I had the PI 4 in mind for better performance, but hesitant as I’d need to invest in better power supplies. Using my sons Pi 3B+ that I’ve requisitioned for the initial development.

Man this is fantastic effort! Looking forward to the release. Any idea when that might be?

Soonish?

I have a few boards out for testing right now and I want to make one more change to the pcb (perhaps I’ll get that done this weekend). So… it’ll be at least a couple more weeks to get new boards done and test.

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Someday, my pi 4 will arrive. Maybe.

(It wasn’t backlisted when I ordered it, like six weeks ago. And yet, still no tracking number.)

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Awesome! Please add me to the list if there is one :wink:
I just realised that its pretty much impossible to order pi4 at the moment. So will have to get that first anyway.

I haven’t got a “list” figured out yet. I’ll post here when it’s ready.

FWIW - a pi 3b+ works great. A pi4 is not required.

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are there any benefits from having 3+ over 4 for this? Like power consumption? More ram and better spec with pi4 tho so might be worth waiting once they out again.

…and actually its just 4GB version of Pi4 is out of stock everywhere 2GB is available so this should work.

Is it possible, once you’ve finished the board, to replace the minijacks with 3/4 inch jacks? I know they probably wont fit on the board, but was think just some short wire connections into the board.