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Global Smart Lock
Production smart lock for industrial and telecom sites with 4G LTE remote access and tamper detection.
- ESP32
- LTE
- MQTT
- Altium Designer
Problem
Unmanned sites need remote access control that keeps working when local network infrastructure or primary power is unavailable.
System overview
A production smart lock built on the ESP32, using 4G LTE with MQTT for remote access control, vibration-based tamper detection, and battery failover through an ORing diode arrangement on a 48–72V input.
Responsibilities
- Hardware design: schematic and PCB layout
- Power path design with battery failover
- Firmware for LTE connectivity, MQTT messaging and tamper detection
Hardware architecture
- ESP32 application processor
- 4G LTE cellular modem
- 48–72V DC input with ORing diode battery failover
- Vibration sensing for tamper detection
Firmware architecture
- MQTT client over cellular for remote lock/unlock
- Tamper event detection and reporting
- Power source monitoring and failover handling
Communication interfaces
- LTE / 4G
- MQTT
- UART
- GPIO
Engineering challenges
- Keeping the lock reachable across power source transitions
- Distinguishing genuine tamper events from ambient vibration
Hardware & diagrams
