Matrix - 3-Axis Digital Accelerometer

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Introduction

File:3AD.png
3-Axis Digital Accelerometer
  • This module measures the static acceleration of gravity in three axis x, y and z resulting from motion or shock.
  • Its digital interface is IIC or SPI.
  • It is integrated with an ADXL345 chip with high resolution (13-bit) measurement at ±2g, ±4g, ±8g and ±16g.
  • The module is powered by 5V and converts 5V to 3.3V to ADXL345.

Features

  • I2C, 3.3V
  • 13-bit, up to +-16g
  • 2.54mm spacing pin interface
  • PCB dimension(mm): 16 x 32

重力加速度PCB

  • Pin Description:
Pin Description
INT2 Interrupt
INT1 Interrupt
CS Enable
SCL I2C SCL
SDA I2C SDA
SDO Set Slave Address
5V Supply Voltage 5V
GND Ground

Basic Device Operation

  • The ADXL345 is a small, thin, ultralow 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 acces-sible through either a SPI (3- or 4-wire) or I2C digital interface.
  • The ADXL345 is well suited for mobile device applications. It measures the static acceleration of gravity in tilt-sensing appli-cations, as well as dynamic acceleration resulting from motion or shock. Its high resolution (3.9 mg/LSB) enables measurement of inclination changes less than 1.0°.
  • The ADXL345 conforms to the UM1024 I2C Specification. It supports standard (100 kHz) and fast (400 kHz) data transfer modes. If the CS is tied high it will be in the I2C mode. If the CS or ALT ADDRESS pin is floating or unconnected the state will be unknown.
  • The module's I2C connection diagram is as follows:

三轴重力加速度

Download Matrix Source Code

All the matrix modules' code samples are open source. They are maintained on GitHub - https://github.com/friendlyarm/matrix.git
Each branch in this hub contains the matrix modules' code samples for a board that the matrix modules can work with.

  • The matrix-nanopi branch contains the matrix modules' code samples for the NanoPi
  • The matrix-nanopi2 branch contains the matrix modules' code samples for the NanoPi 2
  • The matrix-tiny4412 branch contains the matrix modules' code samples for the Tiny4412;
  • The matrix-raspberrypi branch contains the matrix modules' code samples for the RaspberryPi;

Please follow the steps below to get the source code:
Install the git utility on a PC running Ubuntu14.04

$ sudo apt-get install git

Clone the matrix code from GitHub

$ git clone https://github.com/friendlyarm/matrix.git

If this is successful a "matrix" directory will be generated, which will contain all the matrix modules' code samples.

Connect to NanoPi 2

Hardware Connection

Please refer to the following connection diagram to connect the Matrix-3_Axis_Digital_Accelerometer to the NanoPi 2:
Matrix-3_Axis_Digital_Accelerometer_nanopi_2

Connection Details:

Matrix-3_Axis_Digital_Accelerometer NanoPi 2
INT2 Not Connected
INT1 Not Connected
CS Pin1
SCL Pin5
SDA Pin3
SDO Pin2
5V Pin4
GND Pin6

Compile Test Program

Please login the matrix hub and enter the nanopi2 branch

$ cd matrix
$ git checkout nanopi2

Compile the Matrix code

$ make CROSS_COMPILE=arm-linux- clean
$ make CROSS_COMPILE=arm-linux-
$ make CROSS_COMPILE=arm-linux- install

Note: please make sure to install the cross compiler "arm-linux-gcc-4.9.3" on your PC, which is used to compile files for the NanoPi 2.
Generated library files are under the "install/lib" directory. The test program is under the "install/usr/bin" directory. The modules are under the "modules" directory.

Run Test Program

Please insert a TF card which is flashed with Debian to a Linux host and mount its boot and rootfs sections.
We assume the rootfs is mounted to /media/rootfs then please run the following commands to copy the module, library and test program to the card

$ cp modules /media/rootfs/ -r
$ cp install/lib/* /media/rootfs/lib/ -d
$ cp install/usr/bin/* /media/rootfs/usr/bin/

Insert this TF card to your NanoPi 2, power on and run the following commands to load the driver.

$ cd /modules
$ insmod adxl34x.ko
$ insmod adxl34x-i2c.ko

Start the matrix-accelerometer program.

$ matrix-accelerometer

Note: this module is not plug and play therefore before running the module please make sure it is connected to a NanoPi 2.
Here is what you should expect:
matrix-accelerometer_result

Code Sample

int main(int argc, char ** argv) 
{
    char position[BUF_SIZE];
    memset(position, 0, BUF_SIZE);
    
    if (adxl34xRead(position) > 0) {
        printf("Get position: %s", position);
    } else {
        printf("Fail to get position\n");        
    }
    return 0;
}

Connect to NanoPi

Preparations

You need to install a Debian on the NanoPi and have a PC which has an appropriate cross compiler ready. For details you can refer to wiki:NanoPi

Hardware Connection

Please refer to the following diagrams to connect "Matrix-3_Axis_Digital_Accelerometer" to the NanoPi
matrix-3_axis_digital_accelerometer_nanopi

Connection Details:

Matrix-3_Axis_Digital_Accelerometer NanoPi
INT2 Floating
INT1 Floating
CS Pin1
SCL Pin5
SDA Pin3
SDO Pin2
5V Pin4
GND Pin6

Compile Test Program

Please login the Matrix git and enter the matrix-nanopi branch

$ cd matrix
$ git checkout matrix-nanopi

Compile the Matrix code

$ make CROSS_COMPILE=arm-linux- clean
$ make CROSS_COMPILE=arm-linux-
$ make CROSS_COMPILE=arm-linux- install

Note: please make sure to install the cross compiler "arm-linux-gcc-4.4.3" on your PC, which is used to compile files for the NanoPi-Debian.
Generated library files are under the "install/lib" directory. Applications are under the "install/usr/bin" directory. The test program for the "Matrix-3_Axis_Digital_Accelerometer" module is "matrix-3_axis_digital_accelerometer".

Run Test Program

Please copy the library files and test program to the NanoPi

$ cp install/usr/bin/* nanopi_rootfs/usr/bin/
$ cp install/lib/* nanopi_rootfs/lib/ -d

Power on the NanoPi and run the following command in Debian's terminal
Note: this module is not plug and play therefore before running the module please make sure it is connected to a NanoPi.

$ matrix-3_axis_digital_accelerometer

Code Sample

int main(int argc, char ** argv) 
{
    char position[BUF_SIZE];
    memset(position, 0, BUF_SIZE);
    
    if (adxl34xRead(position) > 0) {
        printf("Get position: %s", position);
    } else {
        printf("Fail to get position\n");        
    }
    return 0;
}

Connect to Tiny4412

Preparations

Please refer to the Tiny4412's user's manual to install a UbuntuCore on the Tiny4412 and install an appropriate cross compiler on a PC.
Note: only the Tiny4412SDK-1506 carrier board can work with this module.

Hardware Connection

Please refer to the following diagram to connect the Matrix-3_Axis_Digital_Accelerometer to the Tiny4412
matrix-3_axis_digital_accelerometer_tiny4412

Connection Details:

Matrix-3_Axis_Digital_Accelerometer Tiny4412
INT2 Floating
INT1 Floating
CS CON16 5V
SCL CON18 SCL
SDA CON18 SDA
SDO CON14 5V
5V CON18 5V
GND CON18 GND

Compile Test Program

Please login the Matrix hub and enter the matrix-tiny4412 branch

$ cd matrix
$ git checkout matrix-tiny4412

Compile the Matrix code

$ make CROSS_COMPILE=arm-linux-gnueabihf- clean
$ make CROSS_COMPILE=arm-linux-gnueabihf-
$ make CROSS_COMPILE=arm-linux-gnueabihf- install

Note: please make sure to install the cross compiler "arm-linux-gnueabihf-gcc-4.7.3" on your PC, which is used to compile files for the Tiny4412-UbuntuCore.
Generated library files are under the "install/lib" directory. Applications are under the "install/usr/bin" directory. The test program for the "Matrix-3_Axis_Digital_Accelerometer" module is "matrix-3_axis_digital_accelerometer".

Run Test Program

Please copy the library files and test program to the Tiny4412

$ cp install/usr/bin/* tiny4412_rootfs/usr/bin/
$ cp install/lib/* tiny4412_rootfs/lib/ -d

Power on the Tiny4412 and run the following command in UbuntuCore's terminal
Note: this module is not plug and play therefore before running the module please make sure it is connected to a Tiny4412.

$ matrix-3_axis_digital_accelerometer

Code Sample

int main(int argc, char ** argv) 
{
    char position[BUF_SIZE];
    memset(position, 0, BUF_SIZE);
    
    if (adxl34xRead(position) > 0) {
        printf("Get position: %s", position);
    } else {
        printf("Fail to get position\n");        
    }
    return 0;
}

Connect to RaspberryPi

Connect to Arduino

Resources

ADXL345.pdf