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boards /rodeo-motherboard

Render of the Rev-B rodeo-motherboard at an angle: a square black board with the empty Daisy Seed footprint across the middle, the boxed audio-interface ribbon header and a microSD slot along the top edge, and rows of small white connectors down the sides and along the bottom.
Rev-B— three-quarter view · CAD render

Host board

rodeo-motherboard

Verified

The motherboard has one job: carry the Daisy, the audio, and the connectors everything else plugs into. There are no converters on it: those pins drive a second codec instead, and high-resolution analog moved to an optional expander board. Controls no longer compete for motherboard channels, because the satellite chain grows by adding satellites. It also carries the battery, its charger and a fuel gauge, so the instrument charges over USB-C and runs off the desk.

audio
4 in / 4 out, both codecs in one callback
general-purpose I/O
10 connectors, 8 analog-capable
control growth
satellite chain on USART3
I²C
4 taps, pull-ups on board
storage
internal SD — 1.24 MB/s read, measured
USB
audio, MIDI, serial and disk mode, all on the USB-C
MIDI
on a daughterboard
power
1S Li-ion, charger and fuel gauge
expansion
SPI header, looped byte-exact to 6.2 Mbit/s
Verified

It boots. The Seed came up on this board on 2026-10-28, and nine of the eleven bring-up tests have passed on it since: both codecs, MIDI, the I/O connectors, the satellite chain, the SD card, USB-MIDI, disk mode, USB audio and the SPI header. Only the OLED test has not been run.

Planned

The battery gauge on the board we have is dead, and that is our fault: J1’s pin order is the reverse of every cell in the building, the first one went in backwards and the board got very hot. The MAX17048 has answered on I²C with 0 V ever since. The next revision swaps J1 and adds the reverse protection B1 went without.

Planned

The second codec’s ADC takes corrupted samples whenever its own DAC is playing — a layout fault, SDOUT running 0.15 mm alongside SDIN and SCLK for about 50 mm. Sending the DAC 16-bit words cuts it roughly a hundredfold, which is why USB audio defaults to 16-bit. The next revision moves the trace and adds series resistors.

Not planned

No on-board ADCs. The two ADS114S08s, their 24 pot connectors and the pull-downs are removed; that bank becomes an optional expander on the SPI header.

More views

Top and bottom, from the KiCad files

  • Render of the top of the Rev-B rodeo-motherboard. The audio-interface ribbon header and microSD slot run along the top; connectors labelled MIDI, SPI, CHAIN and SWITCH sit down the right edge; four I2C TAPS and ten GPIO TAPS fill the bottom left beside MAIN POWER and a 1S Li-ion BATT connector. The Daisy Seed footprint is two empty rows of plated holes.
    Rev-B— top · CAD render
  • Render of the back of the Rev-B rodeo-motherboard: black soldermask with a QR code under the words first rodeo? get started here!, the licence block, and a large RODEO MOTHERBOARD wordmark running off the bottom edge.
    Rev-B— bottom · CAD render

Files

Published with the board

Nothing here sits behind a sign-up. Fork a satellite, respin it, and the host still reads it.

  • .kicad_pro KiCad project Schematic, layout, footprints. link pending the public repo
  • .zip Gerbers Fab-ready, plus drill maps. link pending the public repo
  • .csv BOM + CPL Parts and placements. link pending the public repo
  • src Firmware Where the board has its own. link pending the public repo

The rest of the family

Want in?

Rodeo goes to Kickstarter in January 2027. The waitlist hears first, and day-one backers are planned to get an early-bird price. One email to confirm, then nothing until there is news.

You will get one email asking you to confirm. Nothing else until there is something to say, and unsubscribe from any of it.