Library for I2C sensors and some atmel-specific functions. The following sensors can be used with an uniform interface and come with arduino-examples:

• Austria Microsystems TCS3772: light sensor - RGB and clear
• Silicon Labs SI7021: humidity sensor
• Invensense MPU9250: 9DOF - 3 axis acceleration and gyro PLUS AK8963-IC with magnetic-field sensor
• Freescale MPL3115A2: pressure
• Maxim MAX44009: ambient and lux with incredible wide dynamic
• NXP PCF2127: Realtime-Clock with 2ppm
• Bosch BMP280: pressure
• ST L3G-Series: 3 axis gyro / angular rate
• Freescale MAG3110: 3 axis Compass / Magnetic field
• Freescale MMA8451: 3 axis acceleration
• Fairchild FAN5421: Single-Cell Li-Ion Switching Charger
• STM LPS331: Pressure Sensor
• Maxim MAX17047: Fuel Gauge for various Cells

Additional Features:

• AVR: measure VCC of the power-pin
• AVR: emulate a spektrum-serial control
• fast math fn for e-function, power-of with scaling (interpolation with sampling points)
• HDLC: a protocol for serial communication featuring frames, checksum and auto-escaping of characters
• WS2812B: efficient controller