stadia-dongle-esp

Stadia Controller Dongle

ESP32-S3 firmware that bridges Google Stadia controllers (Bluetooth LE) to a PC as a wired Xbox 360 controller + HID mouse + HID keyboard. Wi-Fi captive portal for pairing, button remapping, and OTA updates.

Forked from Scalee/stadia-dongle.

Requirements

• ESP32-S3 module with native USB OTG
• 4 MB flash (default) or 16 MB - configurable via sdkconfig.defaults
• Optional: WS2812/SK6812 RGB LED on GPIO 48 (configurable in menuconfig)
• ESP-IDF v6.x

Flashing

No software needed: use the web installer in Chrome or Edge.

danzig666.github.io/stadia-dongle-esp

Connect the ESP32-S3 via the COM/UART USB port, click Install, then move it to the native USB port after flashing.

Build

idf.py set-target esp32s3
idf.py build

sdkconfig.defaults pre-configures NimBLE central, TinyUSB, 240 MHz CPU, and production logging. The default partition table fits 4 MB flash with dual OTA slots.

Flash

idf.py -p <PORT> flash

Merged binary for the ESP Web Tools installer:

esptool.py --chip esp32s3 merge_bin \
  -o docs/firmware-merged.bin \
  --flash_mode dio --flash_freq 80m --flash_size 4MB \
  0x0 build/bootloader/bootloader.bin \
  0x8000 build/partition_table/partition-table.bin \
  0x20000 build/stadia-dongle.bin

Host the docs/ folder and open docs/index.html in Chrome/Edge.

Setup

1. Flash the firmware.
2. On first boot, the dongle starts a setup AP automatically.
3. Join Wi-Fi StadiaDongle-XXXX (open, no password).
4. Open http://192.168.4.1 (captive portal should redirect).
5. Click Start Pairing, then put the controller in Bluetooth mode (hold Stadia + Y until orange flash). This is not really needed, it auto pairs available controllers.
6. Once bonded, the dongle auto-connects on future boots.

Controller Modes

Gamepad Mode

The controller appears as an Xbox 360 Controller for Windows (VID 0x045E, PID 0x0289). Button mapping:

Stadia	Xbox 360
A / B / X / Y	A / B / X / Y
LB / RB	LB / RB
LT / RT	LT / RT (analog)
LS / RS click	LS / RS
Left Stick	Left Stick
Right Stick	Right Stick
D-pad	D-pad
Menu	Start
Options	Back
Stadia button	Guide

Mouse Mode

Hold Assistant + Capture for 2 seconds to toggle. Rumble confirms: 2 pulses = mouse ON, 3 pulses = controller mode restored. Always starts in controller mode after power-on. While active, the Xbox gamepad interface sends neutral reports (sticks centered, buttons released) and all input is routed to the HID mouse.

Stadia input	Mouse action
Left stick	Cursor movement (deadzone, acceleration curve, smoothing)
A	Left click
B	Right click
X	Middle click
D-pad up/down	Scroll wheel (±1 per press)
Right stick Y	Analog scroll wheel
LT (hold)	Precision mode - cursor speed ÷ 3
RT (hold)	Fast mode - cursor speed × 2
Stadia / LB / RB / LS / RS / Menu / Options	Inactive (neutral Xbox reports)

Mouse reports are driven by a 125 Hz hardware timer for smooth, jitter-free movement.

Multi-Controller

Up to 2 controllers can be paired and used concurrently. Each appears as a separate Xbox 360 gamepad. Mouse mode and button mappings are per-controller.

BLE connection interval is negotiated for lowest latency:

Controllers	Connection interval	Update rate
1	7.5 ms	~133 Hz
2	11 – 15 ms	~67 – 91 Hz

When the Wi-Fi AP is active, BLE scanning pauses to reduce coexistence impact; existing controller connections and notifications are unaffected.

Extra Buttons

Assistant and Capture buttons are exposed as a boot keyboard + consumer-control HID interface. Defaults:

Button	Short press	Long press (1 s)
Assistant	F14	Start Web UI
Capture	PrintScreen	(none)

All actions are remappable in the Web UI. 38 actions available: F13–F24, PrintScreen, Escape, Space, Enter, Tab, Backspace, Insert, Delete, Home, End, Page Up/Down, arrow keys, volume/mute, media playback, remote wake only, and Start Web UI.

Web UI

Access at http://192.168.4.1 when the AP is active. Provides:

• BLE and USB connection status, firmware version
• Per-controller battery, name, address, mouse mode status
• Live button state and raw report bytes
• Pairing controls and bonded controller list
• Button action remapping, long-press duration, Web UI timeout
• Firmware update upload (OTA) - untested
• Reboot and disable-Web-UI

The AP starts on fresh flash, when no bonds exist, or by holding Assistant button. It auto-disables after a configurable timeout (default 120 s) when a controller is connected.

USB Remote Wake

When the host PC sleeps, pressing Stadia, Assistant, Capture, or A sends a remote wake signal via tud_remote_wakeup(). Requires BIOS/OS USB wake support. Not always working.

LED Reference

Pattern	Meaning
White pulse	Booting
Dim blue heartbeat	Scanning, no controller connected
Blue-yellow alternating	Scanning + Wi-Fi AP on
Green heartbeat	1 controller in gamepad mode
Faster green heartbeat	2 controllers in gamepad mode
Orange heartbeat	At least 1 controller in mouse mode
Dim purple heartbeat	PC sleeping (USB suspended)
Red pulsing	Error
Purple/yellow alternating	OTA firmware update
Brief white flash	Remote wake sent

Architecture

Stadia BLE ──▶ ble_central.c ──▶ bridge.c ──▶ usb_xbox.c ──▶ Host PC (Xbox 360)
                   │
                   ├──▶ button_actions.c ──▶ hid_extra.c ──▶ Host PC (keyboard)
                   │
                   └──▶ mouse_mode.c ──▶ hid_mouse.c ──▶ Host PC (mouse, 125 Hz)

Host PC (rumble) ──▶ xbox_dev.c ──▶ ble_central.c ──▶ Stadia BLE

License

GNU General Public License v3.0

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