ADXL345 Accelerometer

Cookbook » ADXL345 Accelerometer

Note

This page has been moved to the Components section of the website. Please see http://developer.mbed.org/components/ADXL345-Accelerometer/ .

The ADXL345 is a small, thin, low power, 3-axis accelerometer with high resolution (13-bit) measurement at up to ±16 g. Digital output data is formatted as 16-bit twos complement and is accessible through either a SPI (3- or 4-wire) or I2C digital interface. Libraries for both communication protocols are provided below.

/media/uploads/aberk/adxl345.jpg

Hello World!¶

Import program
ADXL345_HelloWorld - main.cpp

00001 #include "ADXL345.h"
00002 
00003 ADXL345 accelerometer(p5, p6, p7, p8);
00004 Serial pc(USBTX, USBRX);
00005 
00006 int main() {
00007 
00008     int readings[3] = {0, 0, 0};
00009     
00010     pc.printf("Starting ADXL345 test...\n");
00011     pc.printf("Device ID is: 0x%02x\n", accelerometer.getDevId());
00012 
00013     //Go into standby mode to configure the device.
00014     accelerometer.setPowerControl(0x00);
00015 
00016     //Full resolution, +/-16g, 4mg/LSB.
00017     accelerometer.setDataFormatControl(0x0B);
00018     
00019     //3.2kHz data rate.
00020     accelerometer.setDataRate(ADXL345_3200HZ);
00021 
00022     //Measurement mode.
00023     accelerometer.setPowerControl(0x08);
00024 
00025     while (1) {
00026     
00027         wait(0.1);
00028         
00029         accelerometer.getOutput(readings);
00030         
00031         //13-bit, sign extended values.
00032         pc.printf("%i, %i, %i\n", (int16_t)readings[0], (int16_t)readings[1], (int16_t)readings[2]);
00033 
00034     }
00035 
00036 }

ADXL345 Signal Name	mbed pin
Vcc	Vout
Gnd	Gnd
SDA	p5
SDO	p6
SCL	p7
CS	p8

API for SPI¶

Import library
ADXL345 - ADXL345 Class Reference

Public Member Functions
	ADXL345 (PinName mosi, PinName miso, PinName sck, PinName cs)
	Constructor.
int	getDevId (void)
	Read the device ID register on the device.
int	getTapThreshold (void)
	Read the tap threshold on the device.
void	setTapThreshold (int threshold)
	Set the tap threshold.
int	getOffset (int axis)
	Get the current offset for a particular axis.
void	setOffset (int axis, char offset)
	Set the offset for a particular axis.
int	getTapDuration (void)
	Get the tap duration required to trigger an event.
void	setTapDuration (int duration_us)
	Set the tap duration required to trigger an event.
float	getTapLatency (void)
	Get the tap latency between the detection of a tap and the time window.
void	setTapLatency (int latency_ms)
	Set the tap latency between the detection of a tap and the time window.
float	getWindowTime (void)
	Get the time of window between tap latency and a double tap.
void	setWindowTime (int window_ms)
	Set the time of the window between tap latency and a double tap.
int	getActivityThreshold (void)
	Get the threshold value for detecting activity.
void	setActivityThreshold (int threshold)
	Set the threshold value for detecting activity.
int	getInactivityThreshold (void)
	Get the threshold value for detecting inactivity.
void	setInactivityThreshold (int threshold)
	Set the threshold value for detecting inactivity.
int	getTimeInactivity (void)
	Get the time required for inactivity to be declared.
void	setTimeInactivity (int timeInactivity)
	Set the time required for inactivity to be declared.
int	getActivityInactivityControl (void)
	Get the activity/inactivity control settings.
void	setActivityInactivityControl (int settings)
	Set the activity/inactivity control settings.
int	getFreefallThreshold (void)
	Get the threshold for free fall detection.
void	setFreefallThreshold (int threshold)
	Set the threshold for free fall detection.
int	getFreefallTime (void)
	Get the time required to generate a free fall interrupt.
void	setFreefallTime (int freefallTime_ms)
	Set the time required to generate a free fall interrupt.
int	getTapAxisControl (void)
	Get the axis tap settings.
void	setTapAxisControl (int settings)
	Set the axis tap settings.
int	getTapSource (void)
	Get the source of a tap.
void	setPowerMode (char mode)
	Set the power mode.
void	setDataRate (int rate)
	Set the data rate.
int	getPowerControl (void)
	Get the power control settings.
void	setPowerControl (int settings)
	Set the power control settings.
int	getInterruptEnableControl (void)
	Get the interrupt enable settings.
void	setInterruptEnableControl (int settings)
	Set the interrupt enable settings.
int	getInterruptMappingControl (void)
	Get the interrupt mapping settings.
void	setInterruptMappingControl (int settings)
	Set the interrupt mapping settings.
int	getInterruptSource (void)
	Get the interrupt source.
int	getDataFormatControl (void)
	Get the data format settings.
void	setDataFormatControl (int settings)
	Set the data format settings.
void	getOutput (int *readings)
	Get the output of all three axes.
int	getFifoControl (void)
	Get the FIFO control settings.
void	setFifoControl (int settings)
	Set the FIFO control settings.
int	getFifoStatus (void)
	Get FIFO status.

Library for SPI¶

Import library ADXL345

ADXL345 triple axis, digital accelerometer library.

API for I2C¶

Import program ADXL345_I2C

This library enables users to communicate with the ADXL345 accelerometer through the I2C bus on the mbed. The API names are similar and work nearly the same way as those made in the SPI libraries for the ADXL345.

Library for I2C¶

Import program ADXL345_I2C

This library enables users to communicate with the ADXL345 accelerometer through the I2C bus on the mbed. The API names are similar and work nearly the same way as those made in the SPI libraries for the ADXL345.

Reference¶

ADXL345 Datasheet

All wikipages