This is a custom version based on the ATmega328P-PU microcontroller (with the Arduino bootloader pre-installed for convenience).
🧩 Hardware List (Basic Version)
| Item | Specification / Model | Notes |
|---|---|---|
| Microcontroller | ATmega328P-PU | Pre-burned bootloader is most convenient |
| Voltage Regulator | AMS1117-5.0 or LM7805 | Input: 7–12V → Output: 5V |
| 3.3V Regulator | AMS1117-3.3 (optional) | Optional 3.3V output |
| Crystal Oscillator | 16 MHz crystal | Standard clock for ATmega328P |
| Ceramic Capacitors | 22pF × 2 | Placed beside the crystal |
| Electrolytic Caps | 10μF × 2, 100μF × 1 | For power stabilization |
| Resistor | 10kΩ pull-up for RESET | Add others as needed |
| LED + Resistor | LED + 220Ω (e.g., for pin 13) | For status indication / basic testing |
| Push Button | RESET button (4-pin recommended) | For manual reset |
| USB to Serial Module | CH340G / CP2102 / FTDI | For uploading sketches |
| Perfboard or Custom PCB | — | You can use perfboard or custom PCBs |
🛠️ Hardware Assembly Steps
Step 1: Build the Power System
Use a 9V battery, DC adapter, or USB power source.
Input power goes to the 7805 or AMS1117 to output stable 5V.
Don’t forget capacitor filtering:
- 100μF at the input
- 10μF at the output
Step 2: Set Up ATmega328P Core
- VCC to 5V, GND to ground
- Add 16 MHz crystal with two 22pF capacitors to GND
- Pin 1 (RESET) → 10kΩ pull-up resistor to VCC + push button to GND
- Optional: connect a test LED + resistor to pin 13
Step 3: Connect USB to Serial Module
| Serial Module Pin | Connect to ATmega328P |
|---|---|
| TXD | Pin 2 (RX) |
| RXD | Pin 3 (TX) |
| VCC | 5V |
| GND | GND |
| DTR (if present) | Via 100nF capacitor to RESET pin |
Step 4: Power-On Test
Upon powering, the LED should blink (default bootloader runs Blink).
If using a blank chip, use an external ISP programmer to burn the bootloader first.
🧪 Software & Testing
A. Upload Blink Sketch
cppCopyEditvoid setup() {
pinMode(13, OUTPUT);
}
void loop() {
digitalWrite(13, HIGH);
delay(500);
digitalWrite(13, LOW);
delay(500);
}
IDE: Arduino IDE
Board Setting: Select “Arduino UNO”
Port Setting: Choose the correct USB COM port (check via Device Manager)
📌 Additional Tips
- If you’re using a blank ATmega328P chip, you’ll need another Arduino to act as an ISP programmer (Arduino as ISP).
- To reduce board size, consider running the bare chip at 8MHz + 3.3V (fuse settings must be adjusted).
- For PCB design and prototyping, tools like KiCad or EasyEDA are recommended.