• ✅ ATmega328P-PU DIP – Arduino Uno compatible
• 🔌 FTDI 6-pin header for USB upload
• 🧠 ISP header for bootloader and SPI programming
• 📶 5x I²C headers with VCC, GND, SDA, SCL
• 🖲️ All digital (D2–D13) and analog (A0–A5) pins exposed with GND & 5V
• ⚡ Power input via DC jack (7–30V) and onboard voltage regulators:
  • LM2985-5.0 → 5V
  • AMS1117-3.3 → 3.3V for sensors/ESP
• 🧪 Test/learning-friendly layout with silkscreen labels
• 🔘 Onboard RESET button, Power LED, and D13 LED

• All 3-pin headers: [GND | Dn | 5V]
• PWM: D3, D5, D6, D9, D10, D11
• SPI: D10 (SS), D11 (MOSI), D12 (MISO), D13 (SCK)

• Also usable as digital (D14–D19)

GND | +3.3V | +5V | SDA | SCL

DTR | TX | RX | +5V | GND | NC

MISO | VCC
SCK  | MOSI
RST  | GND

1. Connect an FTDI module to the 6-pin FTDI header
2. In Arduino IDE:
   • Select Board: Arduino Uno
   • Choose correct COM port
   • Upload your sketch!

• Use DC Barrel Jack (7–30V)
• 5V & 3.3V rails automatically regulated onboard

Plug sensor into any I²C header and use code like:

#include <Wire.h>

void setup() {
  Wire.begin(); // I2C init
  Serial.begin(9600);
}

void loop() {
  Wire.beginTransmission(0x76); // Example address
  Wire.write(0xF4); // Example command
  Wire.endTransmission();
  delay(1000);
}

• Solder-it-yourself Arduino kit
• I²C sensor lab: OLED, BME280, RTC
• Learn SPI, I2C, UART, PWM
• Expand with ESP8266 via UART/I²C

• Website: https://electroiot.in
• Email: electroiot.in@gmail.com
• GitHub: github.com/ElectroIoT
• YouTube: @ElectroIoT-IN

MIT License – use it freely for education, learning, or hacking!