ATtiny85 Digispark Kickstarter Mini USB Development Board

ATtiny85 Digispark Kickstarter Mini USB Development Board is a thumb-sized Arduino-compatible 8-bit AVR microcontroller board built around the Microchip/Atmel ATtiny85-20SU SOIC-8 MCU with a direct plug-in PCB Male USB Type-A edge connector. Furthermore, it comes pre-flashed with the Micronucleus V-USB bootloader and integrates an onboard 78M05 5V 500mA linear voltage regulator so it can be programmed directly from the Arduino IDE without any external FTDI or ISP programmer. Consequently, it is ideal for ultra-compact USB HID keyboard/mouse automation, NeoPixel WS2812B LED controllers, and miniature battery-powered sensor triggers.

Key Features:

• Cable-Free PCB Male USB-A Plug: Gold/tin-plated PCB edge fingers plug straight into any computer USB Type-A port or USB extension hub for instant power and firmware upload.
• Pre-Installed Micronucleus USB Bootloader: Emulates a low-speed V-USB device for 5 seconds on plug-in, allowing direct sketch uploads from the Arduino IDE over USB.
• Onboard 5V 500mA Linear Regulator (78M05): Accepts external 7V–12V DC (up to 16V peak) on the `VIN` pin and regulates it down to 5.0V DC for standalone operation.
• 6 Multifunction GPIO Pins (P0–P5): Supports 3 × hardware/software PWM channels, 4 × 10-bit ADC analog inputs, and USI-based I2C and SPI communication.
• Dual Onboard Status LEDs: Features a green power indicator LED and a user-programmable red status LED connected to `Pin 1 (PB1)`.

Technical Specifications:

• Microcontroller: Microchip / Atmel ATtiny85-20SU (8-Bit AVR RISC Architecture)
• Clock Speed: 16.5 MHz Internal PLL Clock (Calibrated for V-USB Timing) | 8 MHz / 1 MHz Configurable
• Flash Memory: 8 KB Total (~6.0 KB Available for User Sketches with Micronucleus Bootloader)
• SRAM & EEPROM: 512 Bytes Internal SRAM | 512 Bytes Non-Volatile EEPROM
• Operating Voltage: 5.0V DC via USB Port or `5V` Pin | 7.0V–12.0V DC Recommended via `VIN` Pin
• Digital I/O Pins: 6 Pins (`PB0` through `PB5`; `PB3` and `PB4` Shared with USB D-/D+)
• PWM Channels: 3 Pins (`PB0`, `PB1`, `PB4`)
• Analog Inputs (10-Bit ADC): 4 Channels (`ADC1` on PB2, `ADC2` on PB4, `ADC3` on PB3, `ADC0` on PB5)

Mechanical Specifications:

• PCB Form Factor: Integrated USB Type-A Edge-Tab PCB with 6-Pin I/O Header and 3-Pin Power Header
• Pin Pitch: Standard 2.54 mm (0.1 inch) Through-Hole Pads
• Voltage Protection: Onboard Schottky Reverse-Backfeed Diode between USB 5V and Regulator Rail

Dimensions:

• Length: 26.5 mm (Including USB PCB Tab)
• Width: 18.5 mm
• Thickness: 4.2 mm
• Weight: ≈ 3.0 g

Pinout and Wiring:

• 3-Pin Power Header (`5V, GND, VIN`): Feed 7V–12V DC into `VIN` and `GND`, or supply regulated 5V into `5V`.
• P0 (PB0): I2C `SDA`, SPI `MOSI`, and Hardware `PWM`.
• P1 (PB1): Onboard User LED, SPI `MISO`, and Hardware `PWM`.
• P2 (PB2): I2C `SCL`, SPI `SCK`, External Interrupt `INT0`, and `ADC1`.
• P3 (PB3) & P4 (PB4): `ADC3` / `USB D-` (with 1.5kΩ pull-up) and `ADC2` / `PWM` / `USB D+`.
• P5 (PB5): `ADC0` / Digital I/O (or Active-Low `RESET` depending on fuse configuration).
• Engineering Precaution: In the Arduino IDE, click `Upload` FIRST while the Digispark is unplugged, wait for the console prompt `”Plug in device now…”`, and only then insert the board into your USB port so the 5-second Micronucleus bootloader catches the upload.

Datasheet Reference:

• View Official Microchip ATtiny25/45/85 Microcontroller Datasheet PDF

Commonly Used in:

• Automated USB HID Rubber-Ducky Keystroke Injectors, Volume Knobs, and Macro Keys
• Miniature WS2812B / NeoPixel Wearable RGB LED Controllers
• Ultra-Compact Relay Timers, Servo Testers, and I2C OLED Sensor Displays

Applications:

• USB HID Keyboard & Mouse Emulation: Uses the `DigiKeyboard.h` and `DigiMouse.h` libraries to send automated shortcut keys, passwords, or cursor jiggles over USB.
• Standalone 8-Pin AVR Prototyping: Replaces full-size Arduino UNO/Nano boards in simple tasks that only need 2 to 5 I/O pins.
• Wearable & RC Lighting Effects: Drives addressable RGB LED strips from a 5V BEC or 2S/3S battery via the onboard `VIN` regulator.

Equivalent Models:

• ATtiny85 Micro-USB Development Board: Identical Digispark circuit utilizing a female Micro-USB receptacle instead of the direct plug-in PCB USB-A tab.
• Adafruit Trinket 5V (ATtiny85): Original Adafruit 8KB ATtiny85 miniature board with Micro-USB connector.
• Arduino Nano V3.0 (ATmega328P): Full 32KB flash / 22-GPIO board with dedicated CH340 USB-serial chip, whereas the ATtiny85 Digispark is less than one-third the size and supports native V-USB HID emulation.

Package Includes:

• 1 × ATtiny85 Digispark Kickstarter Mini USB Development Board