MEGA2560 PRO MINI ATmega2560-16AU CH340G Development Board Users Guide

The MEGA2560 Pro Mini is a compact, low-cost, Arduino Mega 2560-compatible development board built around the ATmega2560-16AU microcontroller. It delivers the same processing power and I/O capabilities as the full-size Arduino Mega 2560, but in a dramatically smaller form factor of just 54mm × 38mm (2.1″ × 1.5″) — making it ideal for embedded projects, prototyping, and space-constrained applications.

This board uses the CH340G USB-to-UART interface and connects via a Micro-USB cable.

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1. Install Software (Required Before Connecting)

✅ Install Arduino IDE

Download and install the Arduino IDE:

https://www.arduino.cc/en/software

✅ Windows Only: Install CH340 Driver (Critical Step)

This board uses a CH340 USB interface, which requires a driver on many Windows systems.

Before plugging in your board:

1. Install the CH340 driver - See Appendix A below for detailed driver installation instructions
2. Restart your computer
3. Then connect the board

⚠️ If you skip this step, your board will not appear in the Arduino IDE.

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2. Connect the Board

Plug the included Micro-USB cable into your board and computer.

✅ The power LED should turn ON

🔌 If Your Board Is Not Detected

The most common issue is using the wrong USB cable.

• ❌ Charge-only cables will power the board but will NOT allow communication
• ✅ Data cables will both power the board AND allow programming

How to tell the difference: A data-capable USB cable will cause your computer to make a "device connected" sound or show a new COM port in Device Manager (Windows) or /dev/tty entry (Mac/Linux).

Try a different cable — this solves the problem in most cases.

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3. Configure the Arduino IDE

Select the Correct Board

1. Open the Arduino IDE
2. Go to Tools → Board
3. Select "Arduino Mega or Mega 2560"

Select the Correct Processor

1. Go to Tools → Processor
2. Select "ATmega2560 (Mega 2560)"

Select the Correct Port

1. Go to Tools → Port
2. Select the COM port that appeared when you plugged in the board
   • Windows: Look for COM3, COM4, etc.
   • Mac: Look for /dev/cu.usbserial-xxxx or /dev/cu.wchusbserial-xxxx
   • Linux: Look for /dev/ttyUSB0 or similar

💡 Tip: If you're unsure which port is correct, unplug the board, check the list, plug it back in, and see which new port appears.

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4. Upload Your First Sketch (Blink Test)

This verifies that your board, cable, driver, and IDE settings are all working correctly.

1. Go to File → Examples → 01.Basics → Blink
2. Click the Upload button (→ arrow icon)
3. Wait for the message: "Done uploading."

✅ The onboard LED (connected to pin 13) should now blink on and off every second.

If the upload fails, double-check:

• The correct Board is selected ("Arduino Mega or Mega 2560")
• The correct Processor is selected ("ATmega2560 (Mega 2560)")
• The correct Port is selected
• You are using a data-capable USB cable
• The CH340 driver is installed (Windows)

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5. Board Specifications

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6. Power Supply Options

The MEGA2560 Pro Mini can be powered in two ways:

⚠️ Do not exceed 12V on the VIN pin — this may damage the onboard voltage regulator.

💡 Tip: When powered via VIN, the board's onboard 5V regulator provides a stable 5V output to the I/O pins and the 5V pin header.

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7. Pinout Overview

The MEGA2560 Pro Mini breaks out all 54 digital I/O pins, 16 analog inputs, and power/communication pins in a compact dual-row header layout.

Key Pin Groups

💡 Tip: The pin layout on the MEGA2560 Pro Mini is different from the full-size Arduino Mega 2560. Refer to the silkscreen labels printed on the board for accurate pin identification.

MEGA2560 Pro Mini Pinout and Dimensional Drawings

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8. Comparison: MEGA2560 Pro Mini vs. Arduino Mega 2560 vs. Arduino Uno R3

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9. Troubleshooting

❌ Board not detected / No COM port appears

1. Install the CH340 driver (see Step 1 and Appendix A)
2. Try a different USB cable — charge-only cables will not work
3. Try a different USB port on your computer
4. Restart your computer after installing the driver
5. Check Device Manager (Windows) for "USB-SERIAL CH340" under Ports

❌ Upload fails with error

• Verify Board is set to "Arduino Mega or Mega 2560"
• Verify Processor is set to "ATmega2560 (Mega 2560)"
• Verify the correct Port is selected
• Close any other programs that may be using the serial port (e.g., Serial Monitor in another IDE window)

❌ Board powers on but LED doesn't blink after upload

• Confirm the upload completed with "Done uploading." message
• The onboard LED is connected to pin 13 — ensure your sketch uses LED_BUILTIN or pin 13

❌ Erratic behavior or resets

• Check your power supply — insufficient current can cause instability
• If using VIN, ensure voltage is within 7–9V DC
• Avoid drawing more than 20 mA per I/O pin or 800 mA total

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10. Useful Links & Resources

• Getting Started with Arduino: http://envistia.info/ardgetstarted
• Arduino IDE Download: https://www.arduino.cc/en/software
• Arduino Mega 2560 Documentation: https://docs.arduino.cc/hardware/mega-2560/
• Arduino Language Reference: https://www.arduino.cc/reference/en/

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11. Where to Buy the MEGA2560 Pro Mini

Buy the MEGA2560 Pro Mini Microcontroller →

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📄 Appendix A: How to install the CH340G driver on your computer

The CH340 USB IC is made by WCH. You can find the latest version of their drivers in their English translated website here:

http://www.wch-ic.com/downloads/CH341SER_ZIP.html

Click on the “download” button on the WCH page to download the ch341ser.zip file to your computer.

Unzip (extract) the ch341ser.zip file.

Run the Setup application in the CH341SER folder of the unzipped file. See the screenshot below:

Click the “Uninstall” button first to remove any old versions, then click on the “Install” button.

CH340G Driver Verification for Windows

To verify that your CH340G driver is working, you should see a difference in the Windows Device Manager and Arduino IDE Ports after plugging the Arduino board with a CH340 into a USB port on your computer.

Device Manager

To check that the CH340 associates to a COM port, open the Windows Device Manager. You can click the Start or ⊞ (Windows) button and type “device manager” to search for the application.

After opening the Device Manager, you will need to open the Ports (COM & LPT) tree. The CH340 should show up as USB-SERIAL CH340 (COM##). Depending on your computer, the COM port may show up as a different number.

Arduino IDE

If you have the Arduino IDE installed, you should also see a change in the number of available COM Ports (you may need to restart the Arduino IDE for the board to populate). Without the CH340 connected to your computer, in the IDE click on Tools > Port. Take note of the Serial Ports available:

Connect the Arduino board with the CH340 to your computer’s USB port. Click somewhere else on the screen for the menu to refresh itself. Then go back to Tools > Port. A new COM port should appear. By process of elimination, the CH340 should have associated to the new COM port. Select this COM port in order to connect the IDE to your Arduino board.

In the example shown in these two screen shots, the new Arduino CH340 board is associated to COM Port 3.

 

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This guide is provided by Envistia Mall for educational and technical reference purposes. The manufacturer and Envistia LLC (dba Envistia Mall) are not responsible for any damages or losses resulting from the use of this product. Always follow proper electrical safety practices when working with electronic components. Specifications are based on manufacturer data and are subject to change without notice.