ESP32 battery sensor node
Wakes, reads a sensor, reports, sleeps. A sensor node lives for months on one cell by sleeping almost all the time. The ESP32 wakes every 10 s, reads the BME280, reports and goes back to deep sleep. The HT7333 LDO feeds 3.3 V straight to the 3V3 pin with 4 µA of its own, bypassing the DevKit’s AMS1117 (5 mA). Even so, the DevKit’s power LED and USB chip still hang on the 3V3 rail: about 0.8 mA while the chip itself sleeps at 10 µA. A real node uses a bare module, or cuts the LED.
Build it in the labGuided build, test sheet and fault finding, free in your browser.
Parts list
Test procedure
Each test has an expected value and a pass range, like a factory test sheet:
- 3.3 V rail
- Wakes and reports
- Average current over 20 s
How it works
What it does: Wakes, reads a sensor, reports, sleeps.
Build it (guided or ready-made), then run its test procedure below. Every test has an expected value and a pass range, just like a factory test sheet.
Background
Weather stations, soil sensors, beehive monitors, flood gauges.