The ESP32-S3 datasheet says 7µA deep sleep current. Your prototype draws 150µA. Here's why.

The Three Mistakes Everyone Makes

1. Floating GPIO pins. Every unconnected GPIO oscillates between VCC and GND, drawing 10-50µA each. On an ESP32 with 40+ GPIOs, that's potentially hundreds of µA wasted from pins you're not even using.

2. Internal pull-ups. The ESP32's internal pull-ups are ~45KΩ. At 3.3V, each one draws 73µA. Two pull-ups for I2C = 146µA — that's 20x the entire ESP32 deep sleep current.

3. Peripherals you forgot to disable. Clock-gating isn't power-gating. The SPI flash alone in standby draws 5µA.

The Fix

It's not complicated — it's methodical. You need a proper measurement setup, a power budget spreadsheet, and firmware that explicitly manages every power domain and GPIO state.

I built a complete course covering all of this using Zig instead of C — with compile-time hardware config validation, type-safe register access, and ULP coprocessor programming for sensor polling at 10µA average.

Includes a full case study: a production 5-year battery-powered environmental sensor.

If you're building battery-powered IoT products and tired of getting 1/10th the battery life the datasheet promises, check out the course.

Welcome to ESP32 Deep Sleep Power Budgeting with Zig.

What You're Getting

This course takes you from zero Zig embedded experience to shipping production-grade battery-powered ESP32 products with multi-year battery life.

How to Work Through the Course

1. Go sequentially — Lessons build on each other

2. Build alongside the lessons — Have your ESP32 dev board and Zig toolchain ready

3. Use the Mentor Chat — Post your measurements and get feedback

Drop a comment below to introduce yourself. Let's get to work.