The scenario
A compact ESP32-based wearable fitness tracker powered by a single-cell LiPo battery, using a 3.3V LDO for the MCU and sensors, and sharing an I2C bus for the heart rate sensor and OLED display.
What is in this drawing
Read the decisions behind it.
01
Use a 3.3V LDO to power the ESP32 and peripherals from the LiPo battery
02
Connect heart rate sensor and OLED on the same I2C bus with pull-up resistors
03
Add a reset pushbutton with pull-up and a battery voltage divider for ADC monitoring
Use this structure for battery-powered ESP32 wearables, environmental monitors, or any compact IoT device needing I2C sensors, a display, and a stable 3.3V rail.
More like this