Fates - a DIY norns DAC board for Raspberry Pi

I added an internal battery to my Fates, thought I should document the process here.

Caveats:

  • This is not a simple build. I found it fairly quick, but it involves SMD desoldering, drilling out the PCB, physically modifying a lipo battery, desoldering an encoder and a USB port. I’m pretty confident with all those things, if you’re not, I would not recommend doing this the way I’ve done it!
  • I did it this morning and haven’t done any long-term testing or tested how long the battery will last. I think it’s at least an hour, hopefully more. I haven’t tested any specifically intense applications, or tried it with grids etc attached.
  • You can charge from the Fates USB-C port, and use Fates while it charges, but it seems to crash when you pull out the power supply, so power down before doing that. On the upside, it seems to charge and run happily from my Macbook Pro charger.
  • The battery level isn’t visible anywhere, so it will just die without warning.

Goals:

  • I wanted an internal battery without modifying the case
  • I realised I also needed a power switch, so removed the 4th encoder and put a toggle in it’s place
  • I wanted to be able to charge through the existing USB-C plug

1: Prepare the Fates board

  • To make space for the battery, I removed a couple of 10uf electrolytic caps, replacing them with 1206 22uf caps (I didn’t have any 10u), which fit nicely across the pads
  • I removed the 4th encoder, and drilled out enough of the PCB to make space for the switch
  • I found the thinnest wire I have in my workshop and threaded it through the via on the ‘O’ of POWER. This is the +5v inlet from the USB C socket.
  • I cut the trace that runs from the ‘W’ in POWER down to the capacitor. This separates the USB C socket from the rest of the board.

2. Prepare the battery

  • I used this 3000mAh pack from Pimoroni
  • It’s slightly too long, so I VERY CAREFULLY sliced through the Kapton tape to free the little control PCB and fold it back on itself. If you nick the battery it WILL CATCH FIRE so don’t do that.

3. Prepare the charger board

  • I used this MP2636 charge and boost board from Pimoroni
  • Higher up this thread I learned that the board doesn’t work unmodified. I made these changes - read the MP2636 datasheet to make sense of these and find the resistors. I made the changes with a soldering iron, not hot air:
  • rOLIM limits the output power - by default it’s 42.4k = 2.61 amp limit. I changed it to 36K which is 3amps
  • ISET limits the charge power - by default it’s 47.5k = up to 2.5 amps charging. I changed it to 300k, so the battery can only receive 400ma when plugged into power - otherwise the Fates is starved of power while charging.
  • I didn’t add an extra capacitor
  • I removed the larger USB port to make the whole package thinner and easier to connect. This was a faff because it seemed to be attached with super high temperature solder.

4: Assembly and connections

  • Reinstalled the front paneI, put the switch in place - a subminature toggle, with a few washers to make it fit in the bigger hole.
  • Taped the battery into place with Kapton tape - and with a few strips beneath it to make sure nothing pokes into it.
  • Taped the control board on top of the battery
  • Connections - I used wire wrap:
  • The skinny wire you put in the via --> The +5 connection on the smaller USB socket. I actually connected it to the ceramic capacitors.
  • A ground pin on the USB C socket --> The GND connection on the smaller USB socket (the other side of those capacitors!)
  • GND on the larger USB connector --> The spare GND pin on Fates board
  • +5v on the larger USB connector --> One end of the switch
  • The other side of the switch --> The Spare +5v pin on the Fates board

5. What keyboard is that?

  • A Tada68 from KBDfans





44 Likes

Sorry to be all over the place in this thread. I was wondering if anyone knew of a simple solution for WiFi connectivity issues. I re-flashed my sd card recently and this has happened before, where my network shows up and says attempting to connect but never does connect, but it seems as though maybe if that happens on the first attempt, you will be unable to connect via WiFi from that point on, even after reboot. I tried doing it via nmtui “Activate a Connection” as well but get the same issue.

Currently, I have a cat5 cable connected but I would like to use WiFi if at all possible. It would be nice to not have to flash the card again

Looks great! Have you heard of the Pijuice? It is an affordable UPS for RPI devices. It is open sourced and maybe we could get a board made up for fates/norns.

pijuice won’t work:

PiJuice will use up to just five of your GPIO pins (just power and I2C),

Not enough available GPIOS and there’s likely be conflicts with how things are currently assigned.

1 Like

Hi, hope you are doing well and safe.

Sometime ago i build a 64 fates and @okyeron and me could never figure out what the deal was. Frustrating since there are some great 64 scripts out there.

So after a few months i have tried, and no deal.

The only scripts that works its @okyeron “Grid Test” script.

Any one can think of what might be going on? Someone how can figure this out?

Here is a video showing the process…

Hoping some one can think of something :frowning:

This may be better suited to the neotrellis grid thread?

What other scripts have you tested with? What happens when you do? Keeping things simple should be best: Awake? Loom?

sorry wrong thread! i hope the moderators cáñales the change…
@okyeron i have tried all…none work, it’s a led feedback problem. the button presses are recognised fine by norns but the leds don’t work normally i’m the grid. very erratic…like it’s stuck on row 1

I really don’t remember what we tried before and I can’t find previous messages. Perhaps send me a new DM?

i will thanks @okyeron!

I was wondering if the app Pedalboards may be compatible with this release. I am waiting for Fates to arrive this week so I still have no way to try.

Thanks in advance :slight_smile:

Fates is up to date with the most recent norns release (it’s usually in sync within a few days of the official releases) so yes…

Pedalboard should work great. (I did some of the work on clouds/rings pedals from my Fates)

2 Likes

Thanks a lot :relaxed: i can’t wait to try it…

did you ever get anywhere with this usb power issue?

Not power per se. it’s something with usb devices that have HID interfaces causing some wierd stall.

I have a Software fix you can try - whenever I wake up.

Otherwise unplug usb devices when you reboot

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oh ok, thanks. ill try it. yeah, i’ve been leaving them unplugged each time i boot up but it’s pretty difficult to get them recognized afterward, so i haven’t really been able to use midi out or my bluetooth keyboard much

Hi everyone
I wanted to ask a few questions here:

1) To route audio from Fates to modular is convenient use something that brings the volume to the line level?
2) To route audio from Modular to Fates do I have to use an attenuator or is it sufficient to lower the input level from the LEVELS mixer? I don’t remember reading that the audio from the modular could somehow damage the NORNS / FATES.

I have noticed that the output from some scripts comes out lower but and sometimes the gain from the FATES mixer seems not enough.

i use a mutable-intruments EARS as modular level amplifier. can it go well?

Thanks in advance

  1. unless you don’t mind working at a lower volume than the rest of your modular an amp would be best.
  2. I’d use an attenuator before the input to avoid clipping.
1 Like

Thanks for the answer:)
I decided to route the norns’ outputs directly to a mixer. I read in some posts that it is not a good idea to mix line and modular signals to avoid damaging the audio codec.

Update 200604

If you are running a version prior to 200218, DO NOT USE SYSTEM > UPDATE .
You must update manually via SSH. Instructions are on the release page: https://github.com/fates-project/norns/releases/tag/2.4.1

If you are on 200218 or later
use SYSTEM > UPDATE while connected to the internet.
(please report back if you have problems with this)

General Norns update notes and info about this release are on the norns release post here Norns: update 200604

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I have a fates with a wobbly rear power jack which I still haven’t gotten round to reflowing.

In the meantime I just tried powering it via the usb-c on the RaspberryPi and it seemed to work fine (using the headphones output).

Is this ok practice? Anything to be weary of?