DIY ESPHome powered 8 Channel Power Delivery Unit with code, 3d Case & Instructions.
⚡ Ultimate DIY 8-Channel ESP32 PDU - Detailed at BabaBuilds.com - DIY PDU Guide
A professional-grade, 8-channel smart Power Distribution Unit (PDU) built on the ESP32 platform. This project replaces expensive commercial smart PDUs with a fully local, highly customizable solution featuring real-time RMS monitoring, OLED telemetry, and individual relay control.
- 8x Independent Channels: Control up to 8 AC sockets individually via Home Assistant.
- True RMS Monitoring: Measures Voltage (V), Current (A), Power (W), and Energy (kWh).
- Web UI Calibration: Calibrate voltage and current sensors directly from the browser—no code re-uploading required.
- OLED Dashboard: 1.3" display showing IP address, Real-time Voltage, and Total Load.
- Reactive Status LEDs: WS2812b strip provides visual feedback (Rainbow=Idle, Scan=Active, Strobe=Overload).
- Safety First: Uses "Normally Open" relay logic and thermal circuit protection.
- Edge Automation: Safety limits and LED effects run locally on the ESP32, independent of Wi-Fi.
- MCU: ESP32 DevKit V1
- Power: Hi-Link HLK-PM01 (5V)
- Relays: 8-Channel 5V Relay Module (Low-Level Trigger)
- Voltage Sensor: ZMPT101B AC Voltage Sensor
- Current Sensor: WCS1700 Hall Effect Sensor (High Amp)
- Display: 1.3" I2C OLED (SH1106 or SSD1306 driver)
- LEDs: WS2812b Addressable RGB Strip
- Protection: 15A Thermal Circuit Breaker
- Wiring: 14 AWG (2.5mm²) for Mains, 22 AWG for Logic.
| Component | Pin Function | ESP32 GPIO | Notes |
|---|---|---|---|
| Relays 1-8 | Control | 13, 14, 27, 26, 25, 33, 32, 4 | Active HIGH in Config |
| I2C Display | SDA | 21 | |
| I2C Display | SCL | 22 | |
| WS2812b LEDs | Data | 18 | |
| ZMPT101B | Analog Out | 34 | Calibrate via Pot first |
| WCS1700 | Analog Out | 35 | MUST power with 5V (VIN) |
⚠️ WCS1700 Note: You must power the WCS1700 sensor from the VIN (5V) pin. If powered via 3.3V, sensitivity is too low to detect small loads.
This firmware allows dynamic calibration via the Web Server.
1. Voltage Calibration:
- Measure your actual wall voltage with a Multimeter (e.g., 236V).
- Open the Device Web Page (IP Address).
- Enter
236in "Calibrate: Real Voltage". - Click Action: Calibrate Voltage.
2. Current Calibration:
- Plug in a known resistive load (e.g., a 1000W Heater).
- Ensure the "PDU Current" sensor shows some value (not 0.00).
- Enter
1000in "Calibrate: Known Load (Watts)". - Click Action: Calibrate Current.
DANGER: HIGH VOLTAGE This project involves 110V/220V Mains Electricity. Improper wiring can cause fire, injury, or death.
- Always unplug mains power before opening the case.
- Use wire ferrules on all screw terminals.
- Do not rely on the relays as a safety disconnect; use the physical switch/breaker.
- Build at your own risk. The authors accept no liability for damage or injury.
This project is licensed under the MIT License - see the LICENSE file for details.