Freescale的3轴多功能数字加速度计解决方案

Keywords： 3-Axis,Digital Accelerometer, MMA8491Q 
摘要：本演示板提供检测传感器演示使用的Xtrinsic MMA8491Q45°倾斜传感器和3轴加速度计，并且使用了一个透明的塑料外壳。
基本特性：
The MMA8491Q is a low voltage, 3-axis low-g accelerometer housed in a 3 mm x 3 mm QFN package. The device can accommodate two accelerometer configurations, acting as either a 45° tilt sensor or a digital output accelerometer with I2C bus.
• As a 45° Tilt Sensor, the MMA8491Q device offers extreme ease of implementation by using a single line output per axis.
• As a digital output accelerometer, the 14-bit ±8g accelerometer data can be read from the device with a 1 mg/LSB sensitivity. The extreme low power capabilities of the MMA8491Q will reduce the low data rate current consumption to less than 400 nA per Hz.
Features
• Extreme low power, 400 nA per Hz
• Ultra-fast data output time, ~700 s
• 1.95V to 3.6V VDD supply range
• 3 mm x 3 mm, 0.65 mm pitch with visual solder joint inspection
• ±8g full-scale range
• 14-bit digital output, 1 mg/LSB sensitivity
• Output Data Rate (ODR), implementation based from < 1 Hz to 800 Hz
• I2C digital interface
• 3-axis, 45°tilt outputs
方案介绍：
The demo board of the DEMOMMA8491 kit is an out-of-the-box 3-axis MEMS tilt sensor. It showcases a simple tilt sensor implemented with the MMA8491Q device, with 10 additional passive components. The demo is powered by a 3V coin battery and is controlled by one switch button (SW1). When the switch is pressed, the tilt sensor is powered on, and it takes one sample of the current acceleration.
The tilt detection result is simultaneously displayed with 3 LEDs (each LED is paired with one of the X, Y, Z axes). A lit LED indicates that a tilt angle greater than or equal to 45° is detected on that axis. To demonstrate the kit, hold the demo board to the desired position, then press and hold do...