🧾 ATtiny84 Dev Board (GTMSM V0.1) – Specs & Programming Guide

1. 🔋 Power Supply

• VIN input range: 3V to 15V (recommended)

• Recommended VIN for operation: 3V or higher

• Regulated output: 5V (via onboard buck-boost converter)

• Minimum reliable VIN (with diode drop): ~2.8V

• Reverse voltage protection: Schottky diode (PD3S140-7) on VIN input

• ⚠️ Important: Never power the board from more than one source at a time (e.g. VIN and USB simultaneously)

2. 🧠 Microcontroller

• Chip: ATtiny84-20SSU

• Architecture: AVR

• Flash memory: 8 KB

• SRAM: 512 bytes

• EEPROM: 512 bytes

• Operating voltage: 1.8V – 5.5V

• Clock: Internal up to 8 MHz (configurable via fuses)

3. 🔌 I/O & Pinout

• Two 8-pin headers:

  • One header: PA0 to PA5, GND

  • Other header: PB0 to PB3, PA6, PA7, 5V, GND

• Standard GPIO, ADC, SPI, I²C, UART functionality via these pins

4. 🛠️ Programming (Using Arduino Nano as ISP)

🧰 Requirements:

• Arduino Nano

• Jumper wires

• Arduino IDE with ATtinyCore installed

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🔗 Wiring: Arduino Nano → ATtiny84

5. 🧪 Programming Steps

1. Flash the Arduino Nano with the “ArduinoISP” sketch

2. In Arduino IDE:

   • Board: ATtiny84 (No bootloader / ATtinyCore)

   • Programmer: Arduino as ISP

   • Clock: 8 MHz internal (or your choice)

3. Click “Burn Bootloader” to set fuses

4. Use “Upload Using Programmer” to flash your sketch