Summary of Arduino Sketch Read Accelerometer
This Arduino sketch reads data from a 3-axis analog accelerometer (e.g., ADXL335) connected to analog pins A0, A1, and A2. It initializes serial communication at 9600 baud and continuously reads raw analog values for X, Y, and Z axes. The raw values are then calibrated based on a defined offset and scale to represent approximate Earth gravity units. Both raw and calibrated acceleration values are printed to the serial console every 50 milliseconds.
Parts used in the ReadAnalogAccelerometer Project:
- Arduino board
- 3-axis analog accelerometer (e.g., ADXL335)
- Connecting wires
- Serial console (Arduino IDE)
This sketch is used by Exercise: Read Analog Accelerometer.
Full Source Code
The full code is all in one file ReadAccelerometer.ino.
// ReadAccelerometer - read a 3-axis analog accelerometer and display the results to the serial port
//
// Copyright (c) 2016, Garth Zeglin. All rights reserved. Licensed under the
// terms of the BSD 3-clause license as included in LICENSE.
//
// This program assumes that:
//
// 1. A three-axis analog accelerometer such as an ADXL335 is attached to A0,
// A1, and A2. Note: this sensor has buffered voltage outputs and can
// simply connect directly to the analog input pins.
//
// 2. The serial console on the Arduino IDE is set to 9600 baud communications speed.
//
// ================================================================================
// Configure the hardware once after booting up. This runs once after pressing
// reset or powering up the board.
void setup()
{
// Initialize the serial UART at 9600 bits per second.
Serial.begin(9600);
}
// ================================================================================
// Run one iteration of the main event loop. The Arduino system will call this
// function over and over forever.
void loop()
{
// Read the accelerations as uncalibrated values.
int x_raw = analogRead(0);
int y_raw = analogRead(1);
int z_raw = analogRead(2);
// The following will rescale the values to be approximately in Earth gravity units.
const int OFFSET = 335;
const float SCALE = 0.013;
float x = (x_raw - OFFSET) * SCALE;
float y = (y_raw - OFFSET) * SCALE;
float z = (z_raw - OFFSET) * SCALE;
// Print the raw outputs.
Serial.print("Raw: X: ");
Serial.print(x_raw);
Serial.print(" Y: ");
Serial.print(y_raw);
Serial.print(" Z: ");
Serial.print(z_raw);
// Print the calibrated outputs.
Serial.print(" Calib: X: ");
Serial.print(x);
Serial.print(" Y: ");
Serial.print(y);
Serial.print(" Z: ");
Serial.println(z); // println appends an end-of-line character
// Delay for a short interval to create a periodic sampling rate.
delay(50);
}Source: Arduino Sketch ReadAccelerometer
