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MLight

MLight Control Board

MLight is a compact, open-source hardware control board designed to manage auxiliary equipment for a home soldering station built around a digital microscope. It aims to reduce the clutter of multiple power cables and consolidate lighting, display power, and fume extraction into a single, cohesive desktop device.

Key Features

  • Dual Power Input: Can be powered either by an external DC 12V barrel jack or a Quick Charge USB source.
  • Microscope Power Protection: Power is only bypassed to the microscope when the voltage is safely negotiated to 12V.
  • Custom Ring Light: Custom aluminum PCB ring light featuring PWM brightness control.
  • Flicker-Free Brightness Control: The ring light’s PWM frequency is configurable at 1 kHz, 4 kHz, 8 kHz, or 16 kHz to eliminate rolling-shutter artifacts and screen flicker on the microscope’s camera.
  • Fume Extractor Speed Control: Standard 12V output for a 4-pin computer fan with PWM speed control to power a DIY soldering fume extractor.
  • Display Power Output: A dedicated USB port providing 5V at up to 1.5A to power a small external HDMI display.
  • OLED User Interface: Equipped with an SSD1306 OLED screen and a rotary encoder for easy configuration.
  • Non-Volatile Memory: Built-in I2C EEPROM for storing and restoring fan speed, brightness, and PWM frequency settings.

Controls Reference

The board is operated using a single rotary encoder with a push-switch:

ActionDescription
Encoder Short PressSwitch active control between the fan speed and the ring light brightness
Encoder RotateAdjust the value of the currently selected element (brightness or fan speed)
Encoder Long PressToggle the active output of both the fan and the ring light on or off
Encoder Rotate while PressedCycles the ring light’s PWM frequency (1 kHz, 4 kHz, 8 kHz, 16 kHz)

System Architecture

The control board coordinates power distribution and user inputs through a lightweight microcontroller, as shown in the block diagram below:

MLight components block diagram

The UI elements on the OLED screen provide clear real-time feedback on current fan speed percentage, ring light brightness level, and selected PWM frequency:

MLight Control board - display elements

Project Article

Read the backstory and build guide for MLight: 👉 Standardizing the Soldering Workbench: Introducing MLight

Open-Source Resources

All schematics, PCB layout designs, 3D printable enclosures, and bare-metal firmware are fully open-source: