| Symptom | Likely cause | Fix in EAGLE | |-------------------------------|------------------------------------------------|--------------------------------------| | Board not recognized by PC | USB D+/D- swapped or missing pull-up resistors| Check CH340 datasheet for D+/D- | | No serial communication | TX/RX crossed or DTR missing capacitor | Swap TX/RX or add 100nF to DTR→Reset | | Upload fails (timeout) | Auto-reset not working | Check DTR → 100nF → Reset connection | | 3.3V devices don’t work | 3.3V regulator missing/enabled | Check MIC5205 enable pin to +5V | | Crystal doesn’t oscillate | Wrong load caps or long traces | Place caps close to MCU, keep traces short |
Creating a custom PCB based on the Arduino Nano is a right of passage for electronics hobbyists moving from breadboards to professional designs. While you can find pre-made "Arduino Nano" breakouts, designing the schematic yourself in Autodesk Eagle gives you full control and a deeper understanding of the microcontroller.
⚠️ If you manufacture boards, ensure the license allows derivative use (Arduino’s CC BY-SA). arduino nano eagle schematic
Use Labels instead of long green lines. It keeps your schematic clean and readable. Adding the Programming Header
Connect your battery or DC jack to the VIN pin. Always include a 10uF decoupling capacitor near the power pins to filter noise. Connect the Peripherals | Symptom | Likely cause | Fix in
Once you have your library loaded, follow these steps to build your circuit: Add the Component
: Always include decoupling capacitors (like a 0.1uF cap) near the power pins in your schematic to filter out noise that could cause the ATmega328P to reset unexpectedly. Arduino Forum +4 For those looking to build their own Nano from scratch rather than just using it as a module, the official Arduino documentation provides carrier templates and full hardware guides. Are you planning to Use Labels instead of long green lines
Before switching to the Board Layout, verify your schematic passes the :
Even though the Nano has a Mini-USB port, adding an to your schematic is a "pro move." It allows you to burn the bootloader if the chip ever gets corrupted. 📏 Converting to a PCB Layout
Connect the CH340G to the ATmega328P:
Search for "Arduino Nano Eagle Library" to find footprints that include the 30-pin DIP layout. 🛠️ Creating the Schematic in Eagle