Nuon Output Interface¶

Emulates a Nuon DVD player controller via the bidirectional Polyface serial protocol. Supports up to 4 players (expandable to 8), spinner emulation for Tempest 3000, and In-Game Reset (IGR) via hardware GPIO pins.

Protocol¶

Wire protocol: Polyface -- bidirectional serial with CRC error checking
PIO programs: 2 state machines:
polyface_send.pio (sm1) -- Send controller data to console
polyface_read.pio (sm2) -- Read commands from console
Core: Runs on Core 1 (timing-critical)
Polling rate: Console polls at approximately 60Hz

The console sends read/write packets. The adapter responds to probe requests with device identification (type 3, MAGIC = 0x4A554445 "JUDE") and returns button/analog state on controller polls. All packets include CRC-16 error checking (CRC16 = 0x8005).

See Nuon Polyface Protocol for wire-level details.

GPIO Pins¶

Signal	GPIO	Notes
DATAIO	GP2	Bidirectional data line
CLKIN	GP3	Clock input (consecutive with DATAIO)
POWER	GP4	IGR power control
STOP	GP11	IGR stop control

Player Support¶

Max players: 4 (defined in nuon_device.h)
Protocol capacity: Up to 8 players supported by the Polyface protocol

Button Mapping¶

JP_BUTTON_*	Nuon Button	Notes
`JP_BUTTON_B1`	A	Primary action
`JP_BUTTON_B2`	C-Down	Secondary action
`JP_BUTTON_B3`	B	Alternate action
`JP_BUTTON_B4`	C-Left	C-button
`JP_BUTTON_L1`	L	Left shoulder
`JP_BUTTON_R1`	R	Right shoulder
`JP_BUTTON_L2`	C-Up	C-button
`JP_BUTTON_R2`	C-Right	C-button
`JP_BUTTON_S1`	Nuon	System button
`JP_BUTTON_S2`	Start	Start button
`JP_BUTTON_DU/DD/DL/DR`	D-pad	Direct mapping

Left stick is also mapped to D-pad directions.

Nuon Button Constants¶

The Nuon protocol uses non-sequential bit positions:

Button	Bitmask	Bit Position
A	`0x4000`	14
B	`0x0008`	3
Start	`0x2000`	13
Nuon	`0x1000`	12
L	`0x0020`	5
R	`0x0010`	4
Up	`0x0200`	9
Down	`0x0800`	11
Left	`0x0400`	10
Right	`0x0100`	8

Analog Mapping¶

The Nuon protocol supports analog axes via A-to-D channel requests:

Channel	Constant	Description
None	`ATOD_CHANNEL_NONE`	No analog data
Mode	`ATOD_CHANNEL_MODE`	Mode information
X1	`ATOD_CHANNEL_X1`	Left stick X
Y1	`ATOD_CHANNEL_Y1`	Left stick Y
X2	`ATOD_CHANNEL_X2`	Right stick X / spinner
Y2	`ATOD_CHANNEL_Y2`	Right stick Y

Feedback¶

In-Game Reset (IGR)¶

Hardware-based reset via GPIO pins, triggered by button combo:

Combo: Hold L1 + R1 + Start + Select

Tap (release before 2 seconds): Triggers Stop (STOP_PIN) -- returns to DVD menu
Hold (2+ seconds): Triggers Power (POWER_PIN) -- powers off the player

Uses the hotkeys service for reliable combo detection with debouncing.

Spinner Emulation (Tempest 3000)¶

USB mouse X-axis movement is converted to spinner rotation: - Linear response (no acceleration) - 1:1 mouse movement to rotation by default - Adjustable via NUON_SPINNER_SCALE in firmware - Auto-detects when a mouse is connected

Profiles¶

Profiles are defined at the app level. The Nuon output exposes profile accessors through the OutputInterface struct.

Apps Using This Output¶

App	Description
`usb2nuon`	USB/BT controllers to Nuon
`bt2nuon`	Bluetooth controllers to Nuon (Pico W)
`n642nuon`	N64 controllers to Nuon