uLisp Sensor Library

ADXL335 3-Axis Accelerometer

The ADXL335 ^[1] is a triple axis MEMS accelerometer with extremely low noise and a power consumption of only 320 µA. It gives three analogue outputs proportional to g, with a full sensing range of ±3 g. The sensor can operate from between 1.8 V and 3.6 V; some breakout boards include a regulator to allow operation at 5 V.

Breakout board are available from SparkFun ^[2]. or Adafruit ^[3].

Reading the sensor data

The sensor gives three analogue outputs proportional to the g on each axis; the following routine returns a list of the three readings, assuming the X, Y, and Z outputs are connected to ADC pins 0, 1, and 2 respectively:

(defun xyz ()
  (list (analogread 0)
        (analogread 1) 
        (analogread 2)))

1. ^ ADXL355 Datasheet on Analog Devices.
2. ^ SparkFun Triple Axis Accelerometer Breakout - ADXL335 on SparkFun.
3. ^ ADXL335 - 5V ready triple-axis accelerometer on Adafruit.