Matrix - 3-Axis Digital Accelerometer
Contents
1 Introduction
- 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.
2 Features
- I2C, 3.3V
- 13-bit, up to +-16g
- 2.54mm spacing pin interface
- PCB dimension(mm): 16 x 32
- 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 |
3 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:
4 Applications
4.1 Connect to NanoPi M1
Please refer to the following connection diagram to connect the module to the NanoPi M1:
Connection Details:
| Matrix-3_Axis_Digital_Accelerometer | NanoPi M1 |
| INT2 | NC |
| INT1 | NC |
| CS | Pin2 |
| SCL | Pin5 |
| SDA | Pin3 |
| SDO | High, it is connected to the GPIO pin-header's 3.3V |
| 5V | Pin4 |
| GND | Pin6 |
4.2 Connect to NanoPi 2
Please refer to the following connection diagram to connect the module to the NanoPi 2:
Connection Details:
| Matrix-3_Axis_Digital_Accelerometer | NanoPi 2 |
| INT2 | NC |
| INT1 | NC |
| CS | Pin2 |
| SCL | Pin5 |
| SDA | Pin3 |
| SDO | High, it is connected to the GPIO pin-header's 3.3V |
| 5V | Pin4 |
| GND | Pin6 |
4.3 Connect to NanoPi M2 / NanoPi 2 Fire
Please refer to the following connection diagram to connect the module to the NanoPi M2/ NanoPi 2 Fire:
Connection Details:
| Matrix-3_Axis_Digital_Accelerometer | NanoPi M2 |
| INT2 | NC |
| INT1 | NC |
| CS | Pin2 |
| SCL | Pin5 |
| SDA | Pin3 |
| SDO | High, it is connected to the GPIO pin-header's 3.3V |
| 5V | Pin4 |
| GND | Pin6 |
4.4 Connect to NanoPC-T2
Please refer to the following connection diagram to connect the module to the NanoPC-T2:
Matrix-3_Axis_Digital_Accelerometer_NanoPC-T2
Connection Details:
| Matrix-3_Axis_Digital_Accelerometer | NanoPC-T2 |
| INT2 | NC |
| INT1 | NC |
| CS | USB Host 5V |
| SCL | Pin5 |
| SDA | Pin6 |
| SDO | USB Host 5V |
| 5V | Pin29 |
| GND | Pin30 |
4.5 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.
The modules are under the "modules" directory. The driver's source code is in github: https://github.com/friendlyarm/linux-3.4.y.git
5 Compile & Run Test Program
Boot your ARM board with Debian and copy the matrix code:
$ apt-get update && apt-get install git $ git clone https://github.com/friendlyarm/matrix.git
If your cloning is done successfully a "matrix" directory will be generated.
Compile and install Matrix:
$ cd matrix $ make && make install
Run test program:
$ matrix-accelerometerNote: this module is not plug and play therefore before running the module please make sure it is connected to an ARM board.
Here is what you should observe:
The position is (-6, 3, 236)
5.1 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; }
6 Connect to NanoPi
6.1 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
6.2 Hardware Connection
Please refer to the following diagrams to connect "Matrix-3_Axis_Digital_Accelerometer" to the 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 |
6.3 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".
6.4 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
6.5 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; }
7 Connect to Tiny4412
7.1 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.
7.2 Hardware Connection
Please refer to the following diagram to connect the Matrix-3_Axis_Digital_Accelerometer to the 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 |
7.3 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".
7.4 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
7.5 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; }
8 Connect to RaspberryPi
9 Connect to Arduino
10 Resources
11 Update Log
11.1 Feb-23-2016
- Changed CS pin spec in Section 5.1
- Added driver's source code location in Section 5.2
