BrainCo Revo II Community

What is the USB baud rate for the BrainCo Revo II?

The BrainCo Revo II communicates over USB-CDC (USB serial) at 115200 baud. Open the port at exactly 115200 — any other rate will produce unreadable output. The device enumerates as /dev/ttyACM0 on Linux or a COM port on Windows. Commands are newline-terminated JSON strings.

What are the BLE GATT UUIDs for the BrainCo Revo II?

The BrainCo Revo II exposes a BLE GATT service with UUID 0000ffe0-0000-1000-8000-00805f9b34fb. Write commands to characteristic 0000ffe1-0000-1000-8000-00805f9b34fb and subscribe to notifications on 0000ffe2-0000-1000-8000-00805f9b34fb. The same JSON command format is used over both USB and BLE transports.

How does the piano key press mode work?

Piano mode executes a 4-phase press sequence per finger: Phase 1 (20 ms) extends the finger to a neutral hover position (0.15 closure); Phase 2 (30 ms) drives the finger down to the press depth proportional to the velocity parameter (0.55–0.95 closure); Phase 3 holds the key depressed for the requested duration; Phase 4 (20 ms) retracts back to hover.

Different fingers can press concurrently — per-finger asyncio locks prevent dropped notes.

How do I calibrate the BrainCo Revo II fingers?

Send the calibrate command: {"cmd": "calibrate"}. This triggers a per-finger wave sequence: the hand opens fully, then each finger from thumb to pinky closes to 90% and opens again with a 120 ms step between movements. After the wave completes, all fingers settle at the neutral hover position (15% closure). The firmware uses this sequence to establish per-finger travel limits.

Can I control the BrainCo Revo II without a physical device?

Yes. Run brainco_revo_agent.py --mock --session YOUR_SESSION_ID to start a fully simulated hand. Mock mode includes Gaussian noise on position readings, realistic command-count tracking, and the full piano press timing sequence. All platform teleop features — finger position bars, press indicators, session recording — work identically without hardware. You can also run a self-test with --self-test which exercises all API methods.

What is the thumb rotation ratio on the BrainCo Revo II?

The BrainCo Revo II thumb has 2 DOF: flexion and rotation. When setting thumb position via the unified API, rotation is derived as a fixed fraction of the flexion value: rotation = flexion × 0.4 (THUMB_ROTATION_RATIO). This means at 50% thumb closure the rotation actuator moves to 20% of its range. Index through pinky each have 1 DOF (flexion only).

My serial port is "permission denied" on Linux. How do I fix it?

Add your user to the dialout group: sudo usermod -aG dialout $USER. Log out and back in for the group change to take effect. Verify with groups — you should see dialout listed. Then retry opening the port.

What is the difference between set_finger and set_pose?

set_finger controls a single finger: {"cmd":"set_finger","finger":N,"position":P} where N is 0–4 and P is 0–100 (percent). set_pose sets all five fingers atomically in one command: {"cmd":"set_pose","positions":[p0,p1,p2,p3,p4]} — preferred for low-latency simultaneous pose updates.