Wireless sensor node

Design of a battery-powered wireless sensor node built around ESP32-C3 and an LIS3DH accelerometer. Communication is via Bluetooth Low Energy (BLE) to an app on a phone or other device.

The design focus is low standby consumption for long battery life on a single AAA cell. The main processor is fully powered off in sleep while only the accelerometer is active. The sensor wakes the system via a latched interrupt that controls the ESP32 module's EN input. Total idle current is approximately 33 µA, giving an estimated battery life of around 3 years.

The power supply uses a low-quiescent boost converter (TPS613221) that steps the cell's nominal 1.5 V up to 3.3 V.