lock

SinricPro Smart Lock Example

Control a door lock with voice commands using a servo motor.

Hardware

• ESP32 board
• Servo motor (SG90 or similar)
• External 5V power supply for servo (recommended)
• Status LED (optional - built-in LED used)

Wiring

ESP32 GPIO18     → Servo Signal (Orange/Yellow)
External 5V      → Servo VCC (Red)
ESP32 GND + 5V GND → Servo GND (Brown/Black)
ESP32 GPIO2      → Status LED (built-in)
ESP32 GPIO0      → BOOT button (built-in)

Important: Servos can draw significant current. Use an external 5V power supply for the servo, not the ESP32's 3.3V pin.

Features

• Lock/unlock control via voice
• Servo motor for physical lock mechanism
• Manual button control
• Status LED (on=unlocked, off=locked)
• Event reporting to SinricPro

Voice Commands

• "Alexa, lock the door"
• "Alexa, unlock the door"
• "Alexa, is the door locked?"

Build

cd examples/lock
idf.py build flash monitor

Configuration

Edit main/lock_example.c - update WiFi and SinricPro credentials.

For different GPIO pins or servo angles, modify:

#define SERVO_GPIO              (18)
#define STATUS_LED_GPIO         (2)
#define BUTTON_GPIO             (0)
#define SERVO_LOCKED_ANGLE      (0)    /* Adjust for your lock */
#define SERVO_UNLOCKED_ANGLE    (90)   /* Adjust for your lock */

Servo Calibration

Different servos may require different angles. Test your servo:

1. Set SERVO_LOCKED_ANGLE to the angle where lock bolt is fully extended
2. Set SERVO_UNLOCKED_ANGLE to the angle where lock bolt is fully retracted
3. Typical ranges: 0-90° or 0-180° depending on your mechanism

Physical Button

Press the BOOT button (GPIO0) to manually toggle lock state. The new state is sent to SinricPro.

Security Note

This is a demonstration example. For production smart locks:

• Add tamper detection
• Add battery backup
• Add manual override mechanism
• Add audit logging
• Consider fail-secure vs fail-safe requirements