Difference between revisions of "Matrix - 3-Axis Digital Accelerometer"

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Line 1: Line 1:
−
[[Matrix - 3-Axis Digital Accelerometer|English]]
+
[[Matrix - 3-Axis Digital Accelerometer/zh|查看中文]]
  
−
==介绍==
+
==Introduction==
 
[[File:3AD.png|thumb|3-Axis Digital Accelerometer]]
 
[[File:3AD.png|thumb|3-Axis Digital Accelerometer]]
−
* 模块Matrix-3_Axis_Digital_Accelerometer用于测量x\y\z方向上的加速度，进而计算速度。
+
* This module measures the static acceleration of gravity in three axis x, y and z resulting from motion or shock.
−
* 搭载了一颗ADXL345芯片，可以使用IIC或SPI进行通信。
+
* Its digital interface is IIC or SPI.
−
* 13-bit精度，采集范围可以是+-2g，+-4g，+-8g和+-16g，既能测定动态加速度，也能测定静态加速度。
+
* It is integrated with an ADXL345 chip with high resolution (13-bit) measurement at ±2g, ±4g, ±8g and ±16g.
−
* 采用5V供电，PCB上的电源转换芯片输出3.3V给ADXL345。
+
* The module is powered by 5V and converts 5V to 3.3V to ADXL345.
  
−
==特性==
+
==Features==
−
* I2C接口，3.3V
+
* I2C, 3.3V
−
* 13-bit，up to +-16g
+
* 13-bit, up to +-16g
−
* 2.54mm排针接口，接线方便，通用性强
+
* 2.54mm spacing pin interface
−
* +-16g，13-bit精度
+
* PCB dimension(mm): 16 x 32
−
* PCB尺寸（mm）：16x32
+
 
[[File:adxpcb.png|frameless|400px|重力加速度PCB]]
 
[[File:adxpcb.png|frameless|400px|重力加速度PCB]]
  
−
* 引脚说明：<br>
+
* Pin Description: <br>
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
−
|名称 || 描述        
+
|Pin || Description        
 
|-
 
|-
−
|INT2    || 中断引脚
+
|INT2    || Interrupt
 
|-
 
|-
−
|INT1    || 中断引脚
+
|INT1    || Interrupt
 
|-  
 
|-  
−
|CS     || 使能引脚
+
|CS       || Enable
 
|-
 
|-
 
|SCL    || I2C SCL
 
|SCL    || I2C SCL
Line 31: Line 30:
 
|SDA    || I2C SDA
 
|SDA    || I2C SDA
 
|-
 
|-
−
|SDO     || 设置slave address
+
|SDO   || Set Slave Address
 
|-
 
|-
−
|5V     || 电源5V
+
|5V       || Supply Voltage 5V
 
|-
 
|-
−
|GND    || 地
+
|GND    || Ground
 
|}
 
|}
  
−
==工作原理==
+
==Basic Device Operation==
−
* ADXL345 是一款小巧纤薄的低功耗三轴加速度计，可以对高达±16 g的加速度进行高分辨率（13 位）测量。数字输出数据为 16 位二进制补码格式，可通过SPI （3 线或 4 线）或者I2C数字接口访问。
+
* 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.
−
* ADXL345 非常适合移动设备应用。它可以在倾斜检测应用中测量静态重力加速度，还可以测量运动或冲击导致的动态加速度。它具有高分辨率（4 mg/LSB），能够测量约 0.25°的倾角变化。
+
* 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°.
−
* 由于这里使用的是I2C通信方式，所以只简单的介绍I2C的工作原理，具体时序的实现可自行去查看芯片手册。ADXL345遵循 Philips I2C-总线协议，它支持标准的数据传输模式（100KHz），并且支持快速传输模式（400KHz），采用I2C模式，需要把CS引脚上拉，I2C引脚无连接时，默认模式不存在。
+
* 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.
−
* 这里采用I2C通信，接线方式如下图：
+
* The module's I2C connection diagram is as follows:
 
[[File:三轴重力.png|frameless|400px|三轴重力加速度]]
 
[[File:三轴重力.png|frameless|400px|三轴重力加速度]]
  
−
==下载Matrix源码==
+
==Download Matrix Source Code==
−
Matrix配件相关的代码是完全开源的，统一由一个仓库进行管理：git://github.com/friendlyarm/matrix.git <br>
+
All the matrix modules' code samples are open source. They are maintained on GitHub - git://github.com/friendlyarm/matrix.git <br>
−
该仓库里不同的分支代表着Matrix配件所支持的不同开发板。<br>
+
Each branch in this hub contains the matrix modules' code samples for a board that the matrix modules can work with.<br>
−
* nanopi分支用于支持NanoPi；
+
* The matrix-nanopi branch contains the matrix modules' code samples for the NanoPi
−
* nanopi2分支用于支持NanoPi 2；
+
* The matrix-tiny4412 branch contains the matrix modules' code samples for the Tiny4412;
−
* tiny4412分支用于支持Tiny4412；
+
* The matrix-raspberrypi branch contains the matrix modules' code samples for the RaspberryPi;
−
* raspberrypi分支用于支持RaspberryPi；
+
  
−
在主机PC上安装git，以Ubuntu14.04为例：
+
Please follow the steps below to get the source code:<br>
 +
Install the git utility on a PC running Ubuntu14.04
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ sudo apt-get install git
 
$ sudo apt-get install git
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
克隆Matrix配件代码仓库：
+
Clone the matrix code from GitHub
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ git clone git://github.com/friendlyarm/matrix.git
 
$ git clone git://github.com/friendlyarm/matrix.git
 
</syntaxhighlight>
 
</syntaxhighlight>
−
克隆完成后会得到一个名为matrix的目录，里面存放着所有Matrix配件的代码。
+
If this is successful a "matrix" directory will be generated, which will contain all the matrix modules' code samples.
  
−
==与NanoPi 2连接使用==
+
==Connect to NanoPi==
−
===准备工作===
+
===Preparations===
−
在NanoPi 2上运行Debian系统，然后在主机PC上安装并使用相应的编译器，参考wiki: [[NanoPi_2/zh|NanoPi_2]] & [[How_to_build_the_Compiling_Environment/zh|How to Build the Compiling Environment]]。<br>
+
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/zh|NanoPi]]
−
注意: 只有使用s5p4418-nanopi2-matrix分支编译出来的内核才能配合Matrix配件正常工作。<br>
+
−
下载NanoPi 2内核源代码并编译：<br>
+
−
<syntaxhighlight lang="bash">
+
−
$ git clone https://github.com/friendlyarm/linux-3.4.y.git
+
−
$ cd linux-3.4.y
+
−
$ git checkout s5p4418-nanopi2-matrix
+
−
$ make nanopi2_linux_defconfig
+
−
$ touch .scmversion
+
−
$ make
+
−
</syntaxhighlight>
+
−
编译好后的uImage位于内核源码arch/arm/boot/目录下，把该uImage替换掉SD卡boot分区上的uImage即可。<br>
+
  
−
===硬件连接===
+
===Hardware Connection===
−
参考下图连接模块Matrix-3_Axis_Digital_Accelerometer和NanoPi 2：<br>
+
Please refer to the following diagrams to connect "Matrix-3_Axis_Digital_Accelerometer" to the NanoPi <br>
−
[[File:Matrix-3_Axis_Digital_Accelerometer_nanopi_2.jpg|frameless|600px|Matrix-3_Axis_Digital_Accelerometer_nanopi_2]]
+
[[File:matrix-3_axis_digital_accelerometer_nanopi.jpg|frameless|600px|matrix-3_axis_digital_accelerometer_nanopi]]
  
−
连接说明：
+
Connection Details:
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
−
|Matrix-3_Axis_Digital_Accelerometer || NanoPi 2        
+
|Matrix-3_Axis_Digital_Accelerometer || NanoPi       
 
|-
 
|-
−
|INT2    || 留空
+
|INT2    || Floating
 
|-
 
|-
−
|INT1    || 留空
+
|INT1    || Floating
 
|-  
 
|-  
−
|CS     || Pin1
+
|CS       || Pin1
 
|-
 
|-
 
|SCL    || Pin5
 
|SCL    || Pin5
Line 98: Line 86:
 
|SDA    || Pin3
 
|SDA    || Pin3
 
|-
 
|-
−
|SDO     || Pin2
+
|SDO   || Pin2
 
|-
 
|-
−
|5V     || Pin4
+
|5V       || Pin4
 
|-
 
|-
 
|GND    || Pin6
 
|GND    || Pin6
 
|}
 
|}
  
−
===编译测试程序===
+
===Compile Test Program===
−
进入Matrix代码仓库，切换到nanopi2分支
+
Please login the Matrix git and enter the matrix-nanopi branch
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ cd matrix
 
$ cd matrix
−
$ git checkout nanopi2
+
$ git checkout matrix-nanopi
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
编译Matrix配件代码
+
Compile the Matrix code
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ make CROSS_COMPILE=arm-linux- clean
 
$ make CROSS_COMPILE=arm-linux- clean
Line 118: Line 106:
 
$ make CROSS_COMPILE=arm-linux- install
 
$ make CROSS_COMPILE=arm-linux- install
 
</syntaxhighlight>
 
</syntaxhighlight>
−
注意：请确保你的主机PC当前使用的交叉编译器为NanoPi 2配套的arm-linux-gcc.4.8.5。<br>
+
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.<br>
−
编译成功后库文件位于install/lib目录下，而测试程序则位于install/usr/bin目录下，模块Matrix-3_Axis_Digital_Accelerometer对应的测试程序为matrix-accelerometer。<br>
+
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".<br>
  
−
===运行测试程序===
+
===Run Test Program===
−
将带有Debian系统的SD卡插入一台运行Linux的电脑，可以挂载SD卡上的boot和rootfs分区。<br>
+
Please copy the library files and test program to the NanoPi
−
假设rootfs分区的挂载路径为/media/rootfs，执行以下命令可将Matrix的所有库文件和测试程序拷贝到NanoPi 2的文件系统上。<br>
+
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
−
$ cp install/usr/bin/* /media/rootfs/usr/bin/
+
$ cp install/usr/bin/* nanopi_rootfs/usr/bin/
−
$ cp install/lib/* /media/rootfs/lib/ -d
+
$ cp install/lib/* nanopi_rootfs/lib/ -d
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
将SD卡重新插入NanoPi 2，上电启动，在Debian的shell终端中执行以下命令运行模块Matrix-3_Axis_Digital_Accelerometer的测试程序。<br>
+
Power on the NanoPi and run the following command in Debian's terminal<br>
 +
Note: this module is not plug and play therefore before running the module please make sure it is connected to a NanoPi.
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
−
$ matrix-accelerometer
+
$ matrix-3_axis_digital_accelerometer
 
</syntaxhighlight>
 
</syntaxhighlight>
−
注意：此模块并不支持热插拔，启动系统前需要确保硬件连接正确。
 
  
−
===代码展示===
+
===Code Sample===
 
<syntaxhighlight lang="c">
 
<syntaxhighlight lang="c">
 
int main(int argc, char ** argv)  
 
int main(int argc, char ** argv)  
 
{
 
{
−
     char *position = (char *) malloc(32);
+
     char position[BUF_SIZE];
−
     memset(position, 0, 32);
+
     memset(position, 0, BUF_SIZE);
 
      
 
      
 
     if (adxl34xRead(position) > 0) {
 
     if (adxl34xRead(position) > 0) {
Line 147: Line 134:
 
         printf("Fail to get position\n");         
 
         printf("Fail to get position\n");         
 
     }
 
     }
−
    free(position);
 
 
     return 0;
 
     return 0;
 
}
 
}
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
==与NanoPi连接使用==
+
==Connect to Tiny4412==
−
===准备工作===
+
===Preparations===
−
在NanoPi上运行Debian系统，然后在主机PC上安装并使用相应的编译器，参考wiki: [[NanoPi/zh|NanoPi]] & [[How_to_build_the_Compiling_Environment/zh|How to Build the Compiling Environment]]。<br>
+
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.<br>
−
注意: 只有使用nanopi-v4.1.y-matrix分支编译出来的内核才能配合Matrix配件正常工作。<br>
+
Note: only the Tiny4412SDK-1506 carrier board can work with this module.
−
下载NanoPi内核源代码并编译: <br>
+
−
<syntaxhighlight lang="bash">
+
−
$ git clone https://github.com/friendlyarm/linux-4.x.y.git
+
−
$ cd linux-4.x.y
+
−
$ git checkout nanopi-v4.1.y-matrix
+
−
$ make nanopi_defconfig
+
−
$ touch .scmversion
+
−
$ make
+
−
</syntaxhighlight>
+
−
编译好后的zImage位于内核源码arch/arm/boot/目录下，把该zImage替换掉NanoPi烧写文件sd-fuse_nanopi/prebuilt下的zImage，重新制作SD卡即可。
+
  
−
===硬件连接===
+
===Hardware Connection===
−
参考下图连接模块Matrix-3_Axis_Digital_Accelerometer和NanoPi：<br>
+
Please refer to the following diagram to connect the Matrix-3_Axis_Digital_Accelerometer to the Tiny4412 <br>
−
[[File:matrix-3_axis_digital_accelerometer_nanopi.jpg|frameless|600px|matrix-3_axis_digital_accelerometer_nanopi]]
+
[[File:matrix-3_axis_digital_accelerometer_tiny4412.jpg|frameless|600px|matrix-3_axis_digital_accelerometer_tiny4412]]
  
−
连接说明：
+
Connection Details:
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
−
|Matrix-3_Axis_Digital_Accelerometer || NanoPi        
+
|Matrix-3_Axis_Digital_Accelerometer || Tiny4412        
 
|-
 
|-
−
|INT2    || 留空
+
|INT2    || Floating
 
|-
 
|-
−
|INT1    || 留空
+
|INT1    || Floating
 
|-  
 
|-  
−
|CS     || Pin1
+
|CS       || CON16 5V
 
|-
 
|-
−
|SCL    || Pin5
+
|SCL    || CON18 SCL
 
|-
 
|-
−
|SDA    || Pin3
+
|SDA    || CON18 SDA
 
|-
 
|-
−
|SDO     || Pin2
+
|SDO   || CON14 5V
 
|-
 
|-
−
|5V     || Pin4
+
|5V       || CON18 5V
 
|-
 
|-
−
|GND    || Pin6
+
|GND    || CON18 GND
 
|}
 
|}
  
−
===编译测试程序===
+
===Compile Test Program===
−
进入Matrix代码仓库，切换到nanopi分支
+
Please login the Matrix hub and enter the matrix-tiny4412 branch
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ cd matrix
 
$ cd matrix
−
$ git checkout nanopi
+
$ git checkout matrix-tiny4412
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
编译Matrix配件代码
+
Compile the Matrix code
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
−
$ make CROSS_COMPILE=arm-linux- clean
+
$ make CROSS_COMPILE=arm-linux-gnueabihf- clean
−
$ make CROSS_COMPILE=arm-linux-
+
$ make CROSS_COMPILE=arm-linux-gnueabihf-
−
$ make CROSS_COMPILE=arm-linux- install
+
$ make CROSS_COMPILE=arm-linux-gnueabihf- install
 
</syntaxhighlight>
 
</syntaxhighlight>
−
注意：请确保你的主机PC当前使用的交叉编译器为NanoPi-Debian配套的arm-linux-gcc-4.4.3。<br>
+
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.<br>
−
编译出来的库文件位于install/lib目录下，而测试程序则位于install/usr/bin目录下，模块Matrix-3_Axis_Digital_Accelerometer对应的测试程序为matrix-accelerometer。<br>
+
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".<br>
  
−
===运行测试程序===
+
===Run Test Program===
−
将带有Debian系统的SD卡插入一台运行Linux的电脑，可以挂载SD卡上的boot和rootfs分区。<br>
+
Please copy the library files and test program to the Tiny4412
−
假设rootfs分区的挂载路径为/media/rootfs，执行以下命令可将Matrix的所有库文件和测试程序拷贝到NanoPi的文件系统上。<br>
+
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
−
$ cp install/usr/bin/* /media/rootfs/usr/bin/
+
$ cp install/usr/bin/* tiny4412_rootfs/usr/bin/
−
$ cp install/lib/* /media/rootfs/lib/ -d
+
$ cp install/lib/* tiny4412_rootfs/lib/ -d
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
将SD卡重新插入NanoPi，上电启动，在Debian的shell终端中执行以下命令运行模块Matrix-3_Axis_Digital_Accelerometer的测试程序。<br>
+
Power on the Tiny4412 and run the following command in UbuntuCore's terminal<br>
 +
Note: this module is not plug and play therefore before running the module please make sure it is connected to a Tiny4412.
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
−
$ matrix-accelerometer
+
$ matrix-3_axis_digital_accelerometer
 
</syntaxhighlight>
 
</syntaxhighlight>
−
注意：此模块并不支持热插拔，启动系统前需要确保硬件正常连接。
 
  
−
===代码展示===
+
===Code Sample===
 
<syntaxhighlight lang="c">
 
<syntaxhighlight lang="c">
 
int main(int argc, char ** argv)  
 
int main(int argc, char ** argv)  
 
{
 
{
−
     char *position = (char *) malloc(32);
+
     char position[BUF_SIZE];
−
     memset(position, 0, 32);
+
     memset(position, 0, BUF_SIZE);
 
      
 
      
 
     if (adxl34xRead(position) > 0) {
 
     if (adxl34xRead(position) > 0) {
Line 235: Line 210:
 
         printf("Fail to get position\n");         
 
         printf("Fail to get position\n");         
 
     }
 
     }
−
    free(position);
 
 
     return 0;
 
     return 0;
 
}
 
}
 +
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
==与Tiny4412连接使用==
+
==Connect to RaspberryPi==
−
===准备工作===
+
−
参考Tiny4412光盘里的《友善之臂Ubuntu使用手册》，在Tiny4412上运行UbuntuCore系统，然后在主机PC上安装并使用相应的编译器。<br>
+
−
注意：只能使用Tiny4412SDK-1506的底板。
+
  
−
===硬件连接===
+
==Connect to Arduino==
−
参考下图连接模块Matrix-3_Axis_Digital_Accelerometer和Tiny4412：<br>
+
−
[[File:matrix-3_axis_digital_accelerometer_tiny4412.jpg|frameless|600px|matrix-3_axis_digital_accelerometer_tiny4412]]
+
  
−
连接说明：
+
==Resources==
−
{| class="wikitable"
+
[http://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdf ADXL345.pdf]
−
|-
+
−
|Matrix-3_Axis_Digital_Accelerometer || Tiny4412     
+
−
|-
+
−
|INT2    || 留空
+
−
|-
+
−
|INT1    || 留空
+
−
|-
+
−
|CS      || CON16 5V
+
−
|-
+
−
|SCL    || CON18 SCL
+
−
|-
+
−
|SDA    || CON18 SDA
+
−
|-
+
−
|SDO    || CON14 5V
+
−
|-
+
−
|5V      || CON18 5V
+
−
|-
+
−
|GND    || CON18 GND
+
−
|}
+
  
−
===编译测试程序===
 
−
进入Matrix代码仓库，切换到tiny4412分支
 
−
<syntaxhighlight lang="bash">
 
−
$ cd matrix
 
−
$ git checkout tiny4412
 
−
</syntaxhighlight>
 
  
−
编译Matrix配件代码
 
−
<syntaxhighlight lang="bash">
 
−
$ make CROSS_COMPILE=arm-linux-gnueabihf- clean
 
−
$ make CROSS_COMPILE=arm-linux-gnueabihf-
 
−
$ make CROSS_COMPILE=arm-linux-gnueabihf- install
 
−
</syntaxhighlight>
 
−
注意：请确保你的主机PC当前使用的交叉编译器为Tiny4412-UbuntuCore配套的arm-linux-gnueabihf-gcc-4.7.3。<br>
 
−
编译出来的库文件位于install/lib目录下，而测试程序则位于install/usr/bin目录下，模块Matrix-3_Axis_Digital_Accelerometer对应的测试程序为matrix-accelerometer。
 
  
−
===运行测试程序===
 
−
将带有UbuntuCore系统的SD卡插入一台运行Linux的电脑，可以挂载SD卡上的boot和rootfs分区。<br>
 
−
假设rootfs分区的挂载路径为/media/rootfs，执行以下命令可将Matrix的所有库文件和测试程序拷贝到Tiny4412的文件系统上。<br>
 
−
<syntaxhighlight lang="bash">
 
−
$ cp install/usr/bin/* /media/rootfs/usr/bin/
 
−
$ cp install/lib/* /media/rootfs/lib/ -d
 
−
</syntaxhighlight>
 
  
−
将SD卡重新插入Tiny4412，上电启动，在UbuntuCore的shell终端中执行以下命令运行模块Matrix-3_Axis_Digital_Accelerometer的测试程序。<br>
 
−
<syntaxhighlight lang="bash">
 
−
$ matrix-accelerometer
 
−
</syntaxhighlight>
 
−
注意：此模块并不支持热插拔，启动系统前需要确保硬件连接正确。
 
  
−
===代码展示===
+
 
 +
<!--
 +
 
 +
 
 +
==Features==
 +
* SPI/I2C，3.3V
 +
* 13-bit，up to +-16g
 +
* 2.54mm spacing pin interface
 +
 
 +
==How To==
 +
===Connection===
 +
*Connect to Tiny4412 SDK (1506)
 +
::GND:  Ground
 +
::VCC:  5V
 +
::INT2: NC, empty pin
 +
::INT1: NC, empty pin
 +
::CS:  5V
 +
::SCL:  I2C SCL
 +
::SDA:  I2C SDA
 +
::SDO:  5V for slave address
 +
 
 +
===Code Sample in C Under Linux===
 
<syntaxhighlight lang="c">
 
<syntaxhighlight lang="c">
−
int main(int argc, char ** argv)  
+
#include <stdio.h>
 +
#include <stdlib.h>
 +
#include <string.h>
 +
#include "libfahw-adxl34x.h"
 +
 
 +
int main(int argc, char ** argv)
 
{
 
{
 
     char *position = (char *) malloc(32);
 
     char *position = (char *) malloc(32);
 
     memset(position, 0, 32);
 
     memset(position, 0, 32);
−
   
+
 
 
     if (adxl34xRead(position) > 0) {
 
     if (adxl34xRead(position) > 0) {
 
         printf("Get position: %s", position);
 
         printf("Get position: %s", position);
 
     } else {
 
     } else {
−
         printf("Fail to get position\n");      
+
         printf("Fail to get position\n");
 
     }
 
     }
 
     free(position);
 
     free(position);
Line 318: Line 269:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
==与RaspberryPi连接使用==
+
===Compile and Run===
 +
<syntaxhighlight lang="bash">
 +
git clone http://github.com/friendlyarm/fa-hardware.git
 +
cd fa-hardware
 +
cd demo
 +
cd matrix-3_axis_digital_accelerometer
 +
make
 +
</syntaxhighlight>
 +
Copy your compiled bin to your board and you are ready to go.
  
−
==与Arduino连接使用==
+
==Resources==
  
−
==相关资料==
+
-->
−
[http://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdf ADXL345.pdf]
+

Revision as of 03:30, 11 November 2015

查看中文

1 Introduction

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.

2 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

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:

三轴重力加速度

4 Download Matrix Source Code

All the matrix modules' code samples are open source. They are maintained on GitHub - git://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-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 git://github.com/friendlyarm/matrix.git

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

5 Connect to NanoPi

5.1 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

5.2 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

5.3 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".

5.4 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

5.5 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;
}

6 Connect to Tiny4412

6.1 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.

6.2 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

6.3 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".

6.4 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

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 RaspberryPi

8 Connect to Arduino

9 Resources

ADXL345.pdf




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