The ESP32 BLE Motion & Surface Mouse is an embedded human-interface project that converts an ESP32 microcontroller into a standalone Bluetooth Low Energy (BLE) Human Interface Device (HID) using an MPU6050 6-axis inertial measurement unit and tactile switches.
The system acts as a standard wireless mouse without needing custom receiver dongles, companion software, or mobile applications. When powered, the ESP32 broadcasts a standard BLE HID peripheral profile. Any host device—including Android smartphones, iPhones, Windows PCs, Linux workstations, or MacBooks—can pair directly via system Bluetooth settings.
The firmware reads high-speed angular velocity (gyroscope) or linear acceleration forces from the MPU6050 over an I2C bus running at 400 kHz. These inertial vectors are conditioned through zero-motion hardware calibration offsets, filtered through a software deadzone to eliminate stationary cursor jitter, scaled for target sensitivity, and transmitted as HID mouse delta packets (move(x, y)) alongside debounced hardware click events.
This project introduces:
ESP32 BLE HID Emulation (BleMouse.h)
I2C Bus Communication & Clock Scaling (Wire.h)
Hardware Required
ESP32 Dev Board
Direct Register Configuration on the MPU6050 (0x6B Power Management)
6-Axis Motion Sensing & Raw Vector Acquisition (MPU6050.h)
Tactile Pushbuttons (Momentary, 2-pin or 4-pin) × 2
Half-Size or Full-Size Breadboard × 1
Male-to-Male Jumper Wires × 1 Set
Micro-USB or Type-C Cable × 1
Host Device (Smartphone, Tablet, or PC with Bluetooth) × 1
Circuit Connections
Design Note: The MPU6050 module communicates over standard I2C. Ensure the pin headers are securely soldered to the breakout board; loose friction-fit connections inside through-holes cause bus communication dropouts. Tactile buttons leverage the ESP32 internal pull-up resistors, eliminating the need for external pull-up or pull-down resistors.
Step 1: Connect the MPU6050 Sensor
Connect the MPU6050 module to the default hardware I2C peripheral of the ESP32:
VCC → ESP32 3.3V (or 5V if the breakout contains an onboard 3.3V LDO regulator)
GND → ESP32 GND
SCL → ESP32 GPIO 22
SDA → ESP32 GPIO 21
Step 2: Connect the Tactile Pushbuttons
Wire each pushbutton between its dedicated GPIO pin and ground:
Left Click Button:
Terminal A → ESP32 GPIO 18
Terminal B → ESP32 GND
Right Click Button:
Terminal A → ESP32 GPIO 5
Terminal B → ESP32 GND
How the ESP32 Firmware Works
Initialize Bluetooth HID Subsystem
Inside setup(), the ESP32 initiates the Bluetooth stack:
bleMouse.begin()
The controller advertises itself under the configured identifier:
Aditya's Gyro Mouse
Host operating systems detect the device natively as a standard wireless pointing device. No custom driver installation is required.
MPU6050 Hardware Wakeup & I2C Setup
The MPU6050 defaults to sleep mode upon receiving power. The firmware configures the I2C interface and issues an explicit wake command:
Wire.begin();
Wire.setClock(400000);
mpu.initialize();
Wire.beginTransmission(0x68);
Wire.write(0x6B); // PWR_MGMT_1 register
Wire.write(0); // Clear SLEEP bit to wake sensor
Wire.endTransmission(true);
