Added Arduino example sketch

firmware/ADXL377_example/ADXL377_example.ino

@@ -0,0 +1,74 @@
+/******************************************************************************
+ADXL377_example.ino
+Simple example for using the ADXL377 accelerometer breakout.
+Jordan McConnell @ SparkFun Electronics
+3 July 2014
+https://github.com/sparkfun/ADXL377_Breakout
+
+This example collects raw accelerometer data from the ADXL377 sensor using
+analog reads and then converts it into common units (g's) and prints the
+result to the Serial Monitor.
+
+Developed/Tested with:
+Arduino Uno
+Arduino IDE 1.0.5
+
+This code is beerware.
+Distributed as-is; no warranty is given. 
+******************************************************************************/
+
+// Make sure these two variables are correct for your setup
+int scale = 200; // 3 (±3g) for ADXL337, 200 (±200g) for ADXL377
+boolean micro_is_5V = true; // Set to true if using a 5V microcontroller such as the Arduino Uno, false if using a 3.3V microcontroller, this affects the interpretation of the sensor data
+
+void setup()
+{
+  // Initialize serial communication at 115200 baud
+  Serial.begin(115200);
+}
+
+// Read, scale, and print accelerometer data
+void loop()
+{
+  // Get raw accelerometer data for each axis
+  int rawX = analogRead(A0);
+  int rawY = analogRead(A1);
+  int rawZ = analogRead(A2);
+
+  // Scale accelerometer ADC readings into common units
+  // Scale map depends on if using a 5V or 3.3V microcontroller
+  float scaledX, scaledY, scaledZ; // Scaled values for each axis
+  if (micro_is_5V) // Microcontroller runs off 5V
+  {
+    scaledX = mapf(rawX, 0, 675, -scale, scale); // 3.3/5 * 1023 =~ 675
+    scaledY = mapf(rawY, 0, 675, -scale, scale);
+    scaledZ = mapf(rawZ, 0, 675, -scale, scale);
+  }
+  else // Microcontroller runs off 3.3V
+  {
+    scaledX = mapf(rawX, 0, 1023, -scale, scale);
+    scaledY = mapf(rawY, 0, 1023, -scale, scale);
+    scaledZ = mapf(rawZ, 0, 1023, -scale, scale);
+  }
+
+  // Print out raw X,Y,Z accelerometer readings
+  Serial.print("X: "); Serial.println(rawX);
+  Serial.print("Y: "); Serial.println(rawY);
+  Serial.print("Z: "); Serial.println(rawZ);
+  Serial.println();
+
+  // Print out scaled X,Y,Z accelerometer readings
+  Serial.print("X: "); Serial.print(scaledX); Serial.println(" g");
+  Serial.print("Y: "); Serial.print(scaledY); Serial.println(" g");
+  Serial.print("Z: "); Serial.print(scaledZ); Serial.println(" g");
+  Serial.println();
+
+  delay(2000); // Minimum delay of 2 milliseconds between sensor reads (500 Hz)
+}
+
+// Same functionality as Arduino's standard map function, except using floats
+float mapf(float x, float in_min, float in_max, float out_min, float out_max)
+{
+  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
+}
+