Overview

This project is a dual-channel smart lab power supply powered by the ESP32 microcontroller. It features a TFT display, a rotary encoder with push-button, and provides preset voltage outputs with precise closed-loop feedback control. Voltage adjustment is done mechanically via stepper motors, which are driven by the ESP32 based on live voltage readings — ensuring accurate and reliable output regulation.

Key Features

• Dual independent output channels

• Selectable voltage presets: 3V, 5V, 7V, and a customizable value per channel

• EEPROM-based preset storage

• OTA (Over-the-Air) firmware updates via Wi-Fi

• Real-time display of:

  • Voltage (V)

  • Current (A)

  • Power (W)

  • Peak power draw (dynamically updated)

Hardware Components

• ESP32 Dev Board (WROOM-32 or ESP32-S3)

• TFT Display (ILI9488 or similar, 320x480)

• Rotary encoder + push button for user input

• INA219 current sensors (one per channel)

• Stepper motors + motor drivers (for mechanical voltage adjustment)

• Potentiometers or analog regulators controlled via motor

• 3D printed enclosure

Closed-Loop Voltage Control

Voltage on each channel is regulated through mechanically adjusted potentiometers, driven by stepper motors. The ESP32 reads the output voltage and adjusts the motor position accordingly — forming a closed-loop feedback system. This approach combines digital precision with the flexibility of analog regulation, while still avoiding the complexity of high-frequency PWM filtering or linear heat dissipation.

Software Features

• Clean, non-blocking Arduino code

• Dynamic UI using TFT_eSPI

• Rotary encoder navigation for preset selection

• EEPROM saving of custom presets

• OTA updates over Wi-Fi

• Continuous tracking of maximum power draw

Voltage Preset System

Each channel provides four selectable presets:

• 3.3V

• 5V

• 7V

• Custom (user-defined, stored in EEPROM)

Presets can be selected with the encoder. The custom preset is editable and saved permanently.

Displayed Information

The TFT screen shows, per channel:

• Output voltage

• Load current

• Instantaneous power consumption

• Peak power usage since last boot

All values refresh in real-time, offering an at-a-glance diagnostic view.

Applications

• Bench power supply for electronics prototyping

• DIY lab equipment

• Embedded systems development

• Smart power management and logging

Planned Features

• SD card logging

• USB-C power input

• Serial terminal control

• Overcurrent detection & protection