Gesture-Controlled Wireless Mouse using IMU and BLE (ESP32)

A conventional mouse needs a desk and a surface, which makes it useless for giving presentations, controlling a smart TV from the couch, or navigating a PC when hand mobility is limited. Existing "air mouse" products solve this with proprietary 2.4 GHz dongles and closed firmware that students cannot open, study or modify. This project rebuilds the idea as an open, student-built embedded system: a hand-held device whose motion is measured by a 6-axis IMU and reported to the host as a standard Bluetooth HID mouse. Because it uses the open HID-over-GATT profile, it pairs with Windows, macOS, Linux, Android and iOS devices with no receiver and no driver install. Along the way the build teaches the full embedded workflow — I2C sensor interfacing, gyroscope/accelerometer fusion, debouncing and power management — on hardware the student holds in their hand.

1. On power-up the firmware holds the device still for about a second and captures the gyroscope bias, while the accelerometer provides an absolute tilt reference.
2. The MPU6050 is sampled at approximately 100 Hz over I2C at 400 kHz fast mode; a complementary filter fuses the fast gyroscope response with the drift-free accelerometer tilt into stable pitch and roll angles.
3. Pitch and roll are mapped to X/Y cursor deltas using the configured speed multiplier, with a small dead-zone around center to kill resting jitter.
4. The two tactile buttons are debounced in firmware (approximately 20 ms); holding the scroll button while tilting switches the report to vertical scroll.
5. The ESP32 packs button states and cursor deltas into standard HID mouse reports and notifies the connected host over BLE HID at approximately 50 reports per second — the host needs no driver or receiver.
6. A 3.7 V Li-ion cell powers the device through a TP4056 charger module with USB charging; the ESP32 and IMU run from the 3.3 V rail.

Tech stack:

• ESP32 (Bluetooth 4.2 + BLE)
• MPU6050 6-axis IMU (GY-521 module)
• BLE HID (HID-over-GATT)
• I2C (400 kHz fast mode)
• ESP-IDF with NimBLE host
• TP4056 Li-ion charger module
• 3D-printed mouse shell
• C/C++ firmware

• [Tilt-to-move cursor] Hand pitch and roll are converted into cursor movement, so the pointer follows the device like an air mouse. A small dead-zone around the rest position suppresses jitter.
• [BLE HID mouse, no dongle] The ESP32 implements the standard HID-over-GATT profile with the ESP-IDF esp_hid / NimBLE stack. It advertises on boot and pairs with any BLE host exactly like a commercial Bluetooth mouse.
• [Left and right click buttons] Two tactile push buttons on the shell act as left and right click, with firmware debouncing so every press registers exactly once.
• [Gesture scroll] Holding the scroll button while tilting sends vertical scroll reports, replacing a physical scroll wheel in the base build.
• [Adjustable pointer speed] A sensitivity constant in the firmware sets how fast the cursor moves per degree of tilt; it is tuned to the buyer's preference before flashing.
• [Power-up calibration] On every boot the firmware captures gyroscope bias while the device rests for about a second, then applies a dead-zone so the cursor does not drift on its own.

Optional customizations (not in the base build)

• Scroll-wheel add-on: a rotary encoder can be fitted as a physical scroll wheel.
• Extra buttons: middle-click or browser back/forward buttons on request.

Future scope

• Air-presentation mode with page-up/page-down gestures.
• Motion-wake deep sleep for longer standby between uses.

• Working hand-held prototype: ESP32, MPU6050 IMU, click buttons, Li-ion cell and charger in a 3D-printed mouse shell
• Complete firmware source (ESP-IDF/NimBLE BLE HID mouse)
• Circuit and wiring documentation with exact component list
• IMU calibration and sensitivity-tuning guide
• Project report PDF, PPT presentation and viva Q&A document
• Demonstration and pairing guidance