Adafruit GEMMA v2 [PID:1222] - (AD5795)

Description:

Want a tiny version? Look no further, GEMMA is a powerful little wearable platform board in a 1" diameter package. Powered by an ATtiny85 and programmable with the Arduino IDE via USB, you'll be able to bring any wearable project to life!

We wanted to design an electronic board that was small enough to fit into any project, and inexpensive enough to use without hesitation. Perfect for when you don't want to give up your Flora and aren't willing to dismantle the project you worked so hard to design. It's our lowest cost controller!

New in version 2! Version 2 was released on March 4, 2015, which is physically and code-identical, but has changed the mini-B connection to a Micro-B USB connector and adds something much requested, an On-Off switch!

The ATtiny85 is a fun processor because despite being so small, it has 8K of flash and 5 I/O pins, including analog inputs and PWM analog outputs. We have designed a USB bootloader so you can connect it to any computer and reprogram it via a USB port like an Arduino (it uses 2 of the 5 I/O pins, leaving 3 pins free for you). In fact, we even made some simple modifications to the Arduino IDE to make it work like a mini-Flora. Perfect for small and simple projects, the GEMMA will be your wearable electronic platform.

Although you can program GEMMA using the Arduino IDE, it is not 100% Arduino compatible. There are a few things that make up for it, such as the fact that it is 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 or receive data.

- Some computer USB v3 ports do not recognize the GEMMA bootloader. Just use a USB v2 port or a USB hub.

Here are some useful specifications!

- Super small: 28mm in diameter and 7mm thick.

- Easy to sew onto solder points for embedding in your wearable project.

- Low cost enough, you can use one for every weekend project.

- Integrated ATtiny85, 8K flash, 512 bytes of SRAM, 512 bytes of EEPROM.

- Internal oscillator runs at 8MHz.

- Ultra low power, consumes only 9 mA while running.

- USB bootloader with an LED indicator, with the USBtinyISP you can program with the Arduino IDE (with some simple configuration modifications).

- Micro-USB jack for power and/or USB charging, you can put it in a box or tape it up and use any USB cable for when you want to reprogram it.

- We really worked hard on the bootloader process to make it robust and foolproof.

- 5.25Kbytes available for use (2.75K used by the bootloader).

- Integrated 3.3V regulator with 150mA output capacity. Input up to 16V, reverse polarity protection, current limit protection and thermal protection.

- Power with a USB cable or external output (e.g. a battery).

- Integrated green LED and pin 1 with a red LED.

- Reset button to enter bootloader or program reset.

- 3 GPIO - The 3 independent I/O pins also have 1 analog input and 2 PWM outputs.

- Hardware with I2C communication capability for breakouts or interconnection with sensors.

Reference link 1

Reference link 2