Fates - a DIY norns DAC board for Raspberry Pi

[etc]

The label says 220 Ohm but the resistors have 2200 printed on them. This is my first time so I’m not sure if that is normal. Here are pics of the package. I got some extras too so you can see they all say 2200.

[zebra]

the parts actually say “two twenty times ten to the zero” (woop)
so: correct

(i’ve nothing else to contribute but concur with @okyeron’s most recent)w

[okyeron]

Handy reference for checking resistor
value by code:

https://www.hobby-hour.com/electronics/smdcalc.php

@etc a photo of the entire top of the board might be useful to look for solder errors

Also - def should do a voltage check for 3.3v as described here. (3.3v at the right side of the electrolytic cap). If not… then could be the voltage regulator and the DAC isnt getting proper power. (might also be good to check your electrolytics are oriented the right way)

Then… dunno if you’ve already reflowed things, but these solder joints look a little dodgy to me

[kburwash]

Sorry, I did a bit of reading but this thread is pretty dense, is there any good reason to put a pi 4 vs a 3+ on my build?

[okyeron]

Not really. Norns software will perform about the same on either.

[etc]

Awesome thank you!

I have not reflowed anything yet but plan to go over the soldering again this week. This was my first time soldering SMD so there was definitely a bit of a learning curve. I’m determined to get it though.

Here are some more pics…

!
IMG_1353|666x500

[kburwash]

are the ‘official’ pi power supplies sufficient (https://www.digikey.ca/en/products/detail/raspberry-pi/T5875DV/6674284)?

they are listed as 2.5a, but the BOM suggests 3a USB-c, is there one that would be recommended instead?

[coreyr]

This should work for a pi 3b+ but will not for a fates built with a pi4. This is a usb micro, not usb c power supply.

[Catchthehare]

Well in an effort to change my encoders I shredded the traces on the 2nd one. Completely disappointed with myself. I don’t suppose there is a fix for stripped trace rings? (The holes where the encoders go into)
Otherwise I’ll consign this to the dead pile and save for a Norns

[desolationjones]

You’ll just need to install a jumper wire between that leg of the encoder and wherever it leads. Flux is your friend here! Don’t bin that board yet

[Catchthehare]

It’s the all the holes for the encoder legs I’m afraid… not quite sure where these lead to? I can try my hand at frankensteining some jumper leads if someone can point me in the right direction

[desolationjones]

Did you only tear off the top side’s pads? Because those don’t look connected to anything. You might be fine; confirm with @okyeron though.

In the future you should try cutting the legs off of the component then remove each leg from its hole individually. It’s rarely worth risking a whole board to save the components.

[Catchthehare]

Yes, thank you for that. This the view form the top but the bottom pads are the same. I recall seeing some schematics somewhere for this encoder and where it connects to on the PI header… any ideas @okyeron?

[okyeron]

FWIW - if you’re feeling unsure about it, send it to me and I’ll fix it up

But… here’s all the encoder connections highlighted:

[Catchthehare]

Thanks very much for that

[JaggedNZ]

Hopefully stating the obvious, but centre pins go to ground.

[Gerald_Stevens]

If you do flying wires, try to twist the pair for each encoder… helps cut down noise pickup.

[Catchthehare]

All sorted with @okyeron and it works like a locomotive now

[thedaniel]

I just recorded a performance featuring a fates and diy grid running MLR for an intermission for an upcoming tech conference and I do mention the project by name - watch this thread for new nerds

[etc]

Does anyone know where I can find a single voltage regulator without having to pay $8 for shipping, either online or at a physical store in Los Angeles?