Switch 2 Pro Controller Example

Brings up the emulated Switch 2 Pro Controller and connects to a real Nintendo Switch 2 console. On boot it runs the pairing-crypto self-test, stands up the custom Nintendo GATT services, and advertises with Nintendo manufacturer data. Once paired it streams input reports continuously (like a real controller); the board’s BOOT button doubles as the A button while connected, and — when bonded but disconnected — a BOOT press broadcasts the wake advertisement to wake the console.

Supported target: ESP32-S3 (default) with ESP-IDF ≥ v6.1, where the official CONFIG_BT_CTRL_BLE_MIN_CONN_INTERVAL_ENABLE (default on) lets the controller accept the console’s 5 ms interval — pairing, input, reconnect, and wake-from-sleep all verified against a real console. The example also builds for the ESP32-C6 (and C61/C2/H2), but the stock NimBLE controller on those chips rejects the 5 ms interval, so only the initial pairing handshake works there (see the component README).

Build, flash, monitor

Default target is esp32s3 (ESP-IDF ≥ v6.1):

idf.py build flash monitor

The console drives the link at a sub-spec 5 ms connection interval for sustained input (it drops even the fresh session to 5 ms ~1.5 s after subscribing) as well as reconnect and wake-from-sleep — only the initial pairing handshake (~15 ms, the first ~1.5 s) works without it. On the S3 the official CONFIG_BT_CTRL_BLE_MIN_CONN_INTERVAL_ENABLE is default-on and covers it; the component warns at configure time if it is missing (older IDF).

Testing with a real Switch 2

  1. Flash and open the monitor. You should see pairing crypto self-test passed, the GATT handle map, and Switch2Pro advertising as 'Pro Controller'.

  2. On the Switch 2: System Settings → Controllers → Pair New Controllers.

  3. Watch the log:

    • connected: peer=… interval=…ms — the negotiated connection interval.

    • pairing: finalised — bonded then AUTH complete: encrypted=true — the handshake and link encryption completed.

    • input-report streaming ENABLED (0x000e) — the console subscribed; input now streams.

  4. Open Test Input Devices (Controllers → your controller) and press the board’s BOOT button — A should register on screen.

Reconnect and wake

After the first pairing the bond is saved to NVS. On the next boot the controller advertises for reconnection. With the console asleep, press BOOT while the log shows connected=false to broadcast the wake advertisement — the console should power on and reconnect without re-pairing. (This needs ESP-IDF ≥ v6.1 on the S3; the C6-family stock controller cannot accept the 5 ms reconnect.)

Verified on ESP32-S3 (ESP-IDF v6.1)

A full session on a real Switch 2 — fresh pair, input testing, then powering the console off and back on with reconnect + input still working — with the official CONFIG_BT_CTRL_BLE_MIN_CONN_INTERVAL_ENABLE (default on, no binary patch). The key moments:

  • connected: … interval=15.00ms — fresh pairing connects at the spec-legal 15 ms, and the 0x15 handshake completes there.

  • CONN PARAMS UPDATE: itvl=5.00ms — ~1.5 s after streaming starts the console drops the link to 5 ms and streams there for the rest of the session. On the pre-v6.1 controller lib this is exactly where the old “~3 s tx-stall” hit; v6.1 applies the update cleanly and input keeps flowing.

  • After the console is powered off (REMOTE_USER_TERMINATED) and a wake broadcast, it reconnects straight at interval=5.00ms and input resumes.

Full monitor log (repetitive heartbeat lines elided) 
[Switch2Pro/I][0.223]: pairing crypto self-test passed
I (224) BLE_INIT: BT controller compile version [51d9dfd]
I (226) BLE_INIT: Bluetooth MAC: f4:12:fa:5a:85:92
[Switch2Pro/I][0.289]: BLE address: using PUBLIC
[Switch2Pro/I][0.290]:   common_input  = 0x000a (0x000a)
[Switch2Pro/I][0.291]:   pro2_input    = 0x000e (0x000e)
[Switch2Pro/I][0.291]:   command       = 0x0014 (0x0014)
[Switch2Pro/I][0.291]:   vib_command   = 0x0016 (0x0016)
[Switch2Pro/I][0.292]:   resp1         = 0x001a (0x001a)
[Switch2Pro/I][0.292]:   resp2         = 0x001e (0x001e)
[Switch2Pro/I][0.296]: Switch2Pro advertising as 'Pro Controller'

# --- fresh pairing, connects at 15 ms ---
[Switch2Pro/I][5.331]: connected: peer=C8:48:05:64:A0:BB interval=15.00ms supervision=2000ms latency=0
[Switch2Pro/I][6.291]: SUBSCRIBE resp1(0x001a) value=0x0001 (on)
[Switch2Pro/I][6.321]: SUBSCRIBE resp2(0x001e) value=0x0001 (on)
[Switch2Pro/I][6.501]: pairing: stored console identity addr c8:48:05:64:a0:bb
[Switch2Pro/I][6.503]: pairing: exchange addresses -> replied with our address 92 85 5a fa 12 f4 (little-endian)
[Switch2Pro/I][6.532]: pairing: exchange keys -> LTK derived, replied B1
[Switch2Pro/I][6.578]: pairing: confirm -> replied B2
[Switch2Pro/I][6.607]: pairing: finalised — bonded
[Switch2Pro/I][6.611]: injected LTK into NimBLE store (rc=0) — ready for LL encryption
[Switch2Pro/I][6.613]: saved bond to NVS (console addr + LTK)
[Switch2Pro/I][6.710]: AUTH complete: encrypted=true bonded=true authenticated=true
[Switch2Pro/I][7.176]: SUBSCRIBE pro2_input(0x000e) value=0x0001 (on)
[Switch2Pro/I][7.176]: input-report streaming ENABLED (0x000e)

# --- console drops the FRESH session to 5 ms ~1.5 s after streaming begins ---
[Switch2Pro/I][7.699]: LINK CHANGE: itvl=15.00ms latency=0 timeout=2000ms tx_phy=2 rx_phy=2
[Switch2Pro/I][8.666]: CONN PARAMS UPDATE: itvl=5.00ms latency=0 timeout=2000ms
[Switch2Pro/I][8.717]: LINK CHANGE: itvl=5.00ms latency=0 timeout=2000ms tx_phy=2 rx_phy=2

# --- streams fine at 5 ms; BOOT press registers as A ---
[switch2_pro example/I][9.749]: connected=true streaming=true A(boot)=false ...
   ... (streaming continuously at 5 ms) ...
[switch2_pro example/I][32.944]: connected=true streaming=true A(boot)=true L+R(auto)=false
   ...

# --- console powered off ---
[Switch2Pro/I][40.616]: SUBSCRIBE pro2_input(0x000e) value=0x0000 (off)
[Switch2Pro/W][40.620]: disconnected: peer=C8:48:05:64:A0:BB reason=REMOTE_USER_TERMINATED (paired=true)
[Switch2Pro/I][40.623]: advertising (reconnect): flags+mfr(26 B) in adv, name in scan response
   ... (advertising for reconnect) ...

# --- BOOT press broadcasts wake; console powers back on and reconnects at 5 ms ---
[Switch2Pro/I][54.114]: wake: broadcasting wake advertisement (user-requested)
[switch2_pro example/I][54.118]: BOOT pressed while disconnected -> sent wake advertisement
[Switch2Pro/I][56.801]: connected: peer=C8:48:05:64:A0:BB interval=5.00ms supervision=2000ms latency=0
[Switch2Pro/I][57.225]: AUTH complete: encrypted=true bonded=true authenticated=true
[Switch2Pro/I][57.226]: SUBSCRIBE pro2_input(0x000e) value=0x0001 (on)
[Switch2Pro/I][57.227]: input-report streaming ENABLED (0x000e)
[Switch2Pro/I][57.731]: LINK CHANGE: itvl=5.00ms latency=0 timeout=2000ms tx_phy=2 rx_phy=2

# --- input works again after wake/reconnect; BOOT press registers as A ---
[switch2_pro example/I][63.454]: connected=true streaming=true A(boot)=true L+R(auto)=false
   ...

Feeding real input

set_input_report() just stores the latest state; a driver-owned task paces the BLE notifications. Replace the BOOT-button read in main with your real button/stick source and call set_input_report() whenever state changes.