Alternate firmware for Doboz Audio XIIO

This is an independent firmware update for Doboz Audio XIIO touchplate keyboard Eurorack module. Use at your own risk.

What's new in V3

Internal clock 60-240 bpm with selectable quarter or sixteenth note quantization
Rewritten glide function with glide time from 1/32note to full note
New settings available via multi-plate touch

Internal clock

CNTR1/INT1 has been repurposed as an adjustable internal clock generator to drive the arp / sequencer. BPM is adjustable by the encoder while in keyboard/note mode and no note plate is pressed or in arp/sequencer mode. Selectable clock resolution: 1/16 note (default, 4 ppqn) and 1/4 note (1ppqn). The current speed and clock resolution is saved with the preset. Note: adjusting internal clock speed while arp/sequencer is playing will cause dropout.

Using an external clock

When the internal clock is disabled, the external clock works as before, with the addition of the XIIO calculating the external clock's speed/BPM.

When the internal clock is engaged and an external clock is connected, the internal clock will be disabled, so the external clock takes priority.

When there are no more falling clock signals on the external clock input for over 2 seconds, the internal clock is enabled again. Note: the speeed of the internal clock will match the external clock's speed.

Rewritten glide

With the new glide implementation it is possible to select the folowing glide times:

1/32 note (XOOO)
1/16 note (OXOO)
1/8 note (XXOO)
1/4 note (OOXO)
1/2 note (XOXO)
Full note (OXXO)

New settings

To toggle the internal clock:

go to settings
press and hold octave - and octave + plates at the same time
use the encoder to toggle between
- XXOO disabled
- OOXX enabled

To set internal clock's quantization time:

go to settings
press and hold octave + and freeze plates at the same time
use the encoder to toggle between
- XXOO 1/16 note,
- OOXX 1/4 note

To toggle internal clock's trigger out:

go to settings
press and hold switch 1 and switch 2 plates at the same time
use the encoder to toggle between
- XXOO disable,
- OOXX enable

To select glide time:

go to settings
press and hold glide time
use the encoder to select from
- OOOO glide off
- XOOO 1/32 note
- OXOO 1/16 note
- XXOO 1/8 note
- OOXO 1/4 note
- XOXO 1/2 note
- OXXO Full note

To select gate length:

go to settings
press and hold note plate 1 and note plate 2 at the same time
use the encoder to select from
- XOOO 25%
- XXOO 50%
- XXXO 75%
- XXXX 90%

Development

arduino-cli compile --fqbn arduino:avr:nano && \
  avrdude -B 1 -V -p m328p -c usbasp -P usb \
          -U flash:w:XIIO_v2_firmware.arduino.avr.nano.hex:i \
          -U flash:w:XIIO_v2_firmware.arduino.avr.nano.with_bootloader.hex:i \
          -U lfuse:w:0xff:m -U hfuse:w:0xda:m -U efuse:w:0xfd:m

icnagy / XIIO