Adafruit GEMMA v2 - Miniature wearable electronic platform

Even though you can program GEMMA using the Arduino IDE, it's not a fully 100% Arduino-compatible. There are some things you trade off for such a small and low cost microcontroller!

• GEMMA does not have a Serial port connection for debugging so the serial port monitor will not be able to send/receive data
• Some computers' USB v3 ports don't recognize the GEMMAs bootloader. Simply use a USB v2 port or a USB hub in between

Here are some useful specifications!

• Super small, only 1.1" / 28mm diameter and 0.28" / 7mm thick.
• Easy-to-sew or solder pads for embedding in your wearable project
• Low cost enough, you can use one for every weekend project
• ATtiny85 on-board, 8K of flash, 512 byte of SRAM, 512 bytes of EEPROM
• Internal oscillator runs at 8MHz
• Ultra low power, draws only 9 mA while running
• USB bootloader with a nice LED indicator looks just like a USBtinyISP so you can program it with the Arduino IDE (with a few simple config modifications)
• Mini-USB jack for power and/or USB uploading, you can put it in a box or tape it up and use any USB cable for when you want to reprogram.
• We really worked hard on the bootloader process to make it rugged and foolproof
• ~5.25K bytes available for use (2.75K taken for the bootloader)
• On-board 3.3V power regulator with 150mA output capability and ultra-low dropout. Up to 16V input, reverse-polarity protection, thermal and current-limit protection.
• Power with either USB or external output (such as a battery) - it'll automatically switch over
• On-board green power LED and red pin #1 LED
• Reset button for entering the bootloader or restarting the program.
• 3 GPIO - The 3 independent IO pins have 1 analog input and 2 PWM output as well.
• Hardware I2C capability for breakout & sensor interfacing.

For more information about GEMMA, check our out Learn guide
 

• TECHNICAL DETAILS

  • Dimensions: 27.98mm / 1.1" round x 7.14mm / 0.28" high
  • Weight: 3.29g