Difference between revisions of "Matrix - Ultrasonic Ranger"

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* The module's sensor emits a sound wave, which bounces off a reflective surface and returns to the sensor. Then, using the amount of time it takes for the wave to return to the sensor, the distance to the object can be computed.
 
* The module's sensor emits a sound wave, which bounces off a reflective surface and returns to the sensor. Then, using the amount of time it takes for the wave to return to the sensor, the distance to the object can be computed.
  
−
==特性==
+
==Features==
−
* 5V供电
+
* 5V Power
−
* 5cm-300cm，精度1cm
+
* Range: 5 cm - 300 cm，Accuracy: 1 cm
−
* 单根gpio操作
+
* One wire gpio
−
* PCB尺寸（mm）：20x40
+
* PCB Dimension (mm): 20 x 40
 
[[File:ultpcb.png|frameless|400px|超声波PCB]]
 
[[File:ultpcb.png|frameless|400px|超声波PCB]]
−
* 引脚说明:
+
* Pin Description:
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
−
|名称 || 描述
+
|Pin || Description
 
|-
 
|-
 
|S    || GPIO
 
|S    || GPIO
 
|-
 
|-
−
|V    || 电源5V
+
|V    || Supply Voltage 5V
 
|-
 
|-
−
|G    || 地
+
|G    || Ground
 
|}
 
|}
  
−
==工作原理==
+
==Basic Device Operation==
−
* 经发射器发射出长约6mm，频率为40KHZ的超声波信号。此信号被物体反射回来由接收头接收，接收头实质上是一种压电效应的换能器。它接收到信号后产生mV级的微弱电压信号。
+
* The sensor emits a 40kHz, 6 mm sound wave, which bounces off a reflective surface and returns to the sensor. The receiver converts ultrasound waves to electrical signals in mV.
−
* cpu向模块Matrix-Ultrasonic_Ranger发送一个高定平信号使其开始测距，模块测距完毕后会回复一个表示时间值的高电平，该高定平的时间长度就是超声波在空气中运行的时间。按照测试距离=(高电平时间*声速(340M/S))/2就可以算出超声波到障碍物的距离。
+
* The master sends a signal to the module starting to emit a sound wave. After the module receives the returned signal it will will generate a high level indicating the elapsed time and the distance will be calculated by distance = (elapsed time * speed of sound)/2.
 
[[File:Ultrasonic Ranger.png|thumb|matrix Ultrasonic Ranger]]
 
[[File:Ultrasonic Ranger.png|thumb|matrix Ultrasonic Ranger]]
  
−
==下载Matrix源码==
+
==Applications==
−
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>
+
===Connect to NanoPi M1===
−
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>
+
Refer to the following connection diagram to connect the module to the NanoPi M1:<br>
−
* nanopi分支包含了Matrix对NanoPi的支持；
+
[[File:Matrix-Ultrasonic_Ranger_nanopi_m1.jpg|frameless|600px|Matrix-Ultrasonic_Ranger_nanopi_m1]]
−
* tiny4412分支包含了Matrix对Tiny4412的支持；
+
−
* raspberrypi分支包含了Matrix对RaspberryPi的支持；
+
  
−
在主机PC上安装git，以Ubuntu14.04为例
+
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Ultrasonic_Ranger || NanoPi M1
 +
|-
 +
|S    || Pin7
 +
|-
 +
|V    || Pin4
 +
|-
 +
|G    || Pin6
 +
|}
 +
 
 +
===Connect to NanoPi 2===
 +
Refer to the following connection diagram to connect the module to the NanoPi 2:<br>
 +
[[File:Matrix-Ultrasonic_Ranger_nanopi_2.jpg|frameless|600px|Matrix-Ultrasonic_Ranger_nanopi_2]]
 +
 
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Ultrasonic_Ranger || NanoPi 2
 +
|-
 +
|S    || Pin7
 +
|-
 +
|V    || Pin4
 +
|-
 +
|G    || Pin6
 +
|}
 +
 
 +
===Connect to NanoPi M2 / NanoPi 2 Fire===
 +
Refer to the following connection diagram to connect the module to the NanoPi M2/ NanoPi 2 Fire:<br>
 +
[[File:Matrix-Ultrasonic_Ranger_nanopi_m2.jpg|frameless|600px|Matrix-Ultrasonic_Ranger_nanopi_m2]]
 +
 
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Ultrasonic_Ranger || NanoPi M2
 +
|-
 +
|S    || Pin7
 +
|-
 +
|V    || Pin4
 +
|-
 +
|G    || Pin6
 +
|}
 +
 
 +
===Connect to NanoPC-T2===
 +
Refer to the following connection diagram to connect the module to the NanoPC-T2:<br>
 +
[[File:Matrix-Ultrasonic_Ranger_NanoPC-T2.jpg|frameless|600px|Matrix-Ultrasonic_Ranger_NanoPC-T2]]
 +
 
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Ultrasonic_Ranger || NanoPC-T2
 +
|-
 +
|S    || Pin15
 +
|-
 +
|V    || Pin29
 +
|-
 +
|G    || Pin30
 +
|}
 +
 
 +
==Compile & Run Test Program==
 +
Boot your ARM board with Debian and copy the matrix code:
 +
<syntaxhighlight lang="bash">
 +
$ apt-get update && apt-get install git
 +
$ git clone https://github.com/friendlyarm/matrix.git
 +
</syntaxhighlight>
 +
If your cloning is done successfully a "matrix" directory will be generated.
 +
 
 +
Compile and install Matrix:
 +
<syntaxhighlight lang="bash">
 +
$ cd matrix
 +
$ make && make install
 +
</syntaxhighlight>
 +
 
 +
Run test program:
 +
<syntaxhighlight lang="bash">
 +
$ matrix-ultrasonic_ranger
 +
</syntaxhighlight>
 +
Note: this module is not plug and play therefore before running the module please make sure it is connected to an ARM board.<br>
 +
Here is what you should observe:<br>
 +
<syntaxhighlight lang="bash">
 +
The distance is  24 cm
 +
</syntaxhighlight>
 +
When you place an object in front of the module the distance between the object and the module will be measured and printed.
 +
 
 +
==Code Sample==
 +
This Matrix code sample can work with all the ARM boards mentioned in this module's wiki. The name of this code sample is "matrix-ultrasonic_ranger". Here is its source code:
 +
<syntaxhighlight lang="c">
 +
int main(int argc, char ** argv)
 +
{
 +
    int distance = -1;
 +
    int pin = GPIO_PIN(7);
 +
    int board;
 +
 
 +
    if ((board = boardInit()) < 0) {
 +
        printf("Fail to init board\n");
 +
        return -1;
 +
    }
 +
    if (board == BOARD_NANOPI_T2)
 +
        pin = GPIO_PIN(15);
 +
   
 +
    system("modprobe "DRIVER_MODULE);
 +
    if (Hcsr04Init(pin) == -1) {
 +
        printf("Fail to init hcsr04\n");
 +
        goto err;
 +
    }
 +
    if (Hcsr04Read(&distance) != -1) {
 +
        printf("The distance is %3d cm\n", distance);
 +
    } else {
 +
        printf("Faid to get distance\n");
 +
    }
 +
    Hcsr04DeInit();
 +
err:
 +
    system("rmmod "DRIVER_MODULE);
 +
   
 +
    return 0;
 +
}
 +
</syntaxhighlight>
 +
For more details about this APIs called in this code sample refer to [[Matrix API reference manual]] <br>
 +
 
 +
<!---
 +
==Download Matrix Source Code==
 +
All the matrix modules' code samples are open source. They are maintained on GitHub - https://github.com/friendlyarm/matrix.git <br>
 +
Each branch in this hub contains the matrix modules' code samples for a board that the matrix modules can work with.<br>
 +
* The nanopi branch contains the matrix modules' code samples for the NanoPi
 +
* The nanopi 2 branch contains the matrix modules' code samples for the NanoPi 2
 +
* The tiny4412 branch contains the matrix modules' code samples for the Tiny4412
 +
* The raspberrypi branch contains the matrix modules' code samples for the RaspberryPi
 +
 
 +
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 https://github.com/friendlyarm/matrix.git
 +
</syntaxhighlight>
 +
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-Ultrasonic_Ranger to the NanoPi 2:<br>
 +
[[File:Matrix-Ultrasonic_Ranger_nanopi_2.jpg|frameless|600px|Matrix-Ultrasonic_Ranger_nanopi_2]]
 +
 
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Ultrasonic_Ranger || NanoPi 2
 +
|-
 +
|S  || Pin7
 +
|-
 +
|V  || Pin4
 +
|-
 +
|G  || Pin6
 +
|}
 +
 
 +
===Compile Test Program===
 +
Please login the matrix hub and enter the nanopi2 branch
 +
<syntaxhighlight lang="bash">
 +
$ cd matrix
 +
$ git checkout nanopi2
 +
</syntaxhighlight>
 +
 
 +
Compile the matrix code
 +
<syntaxhighlight lang="bash">
 +
$ make CROSS_COMPILE=arm-linux- clean
 +
$ make CROSS_COMPILE=arm-linux-
 +
$ make CROSS_COMPILE=arm-linux- install
 +
</syntaxhighlight>
 +
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.<br>
 +
Generated library files are under the "install/lib" directory. The test program is under the "install/usr/bin" directory.<br>
 +
The modules are under the "modules" directory. The driver's source code is in github: https://github.com/friendlyarm/linux-3.4.y.git <br>
 +
 
 +
===Run Test Program===
 +
Please insert a TF card which is flashed with Debian to a Linux host and mount its boot and rootfs sections.<br>
 +
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.<br>
 +
<syntaxhighlight lang="bash">
 +
$ cp modules /media/rootfs/ -r
 +
$ cp install/lib/* /media/rootfs/lib/ -d
 +
$ cp install/usr/bin/* /media/rootfs/usr/bin/
 +
</syntaxhighlight>
 +
 
 +
Insert this TF card to your NanoPi 2, power on and run the following commands to load the driver.<br>
 +
<syntaxhighlight lang="bash">
 +
$ cd /modules
 +
$ insmod matrix_hcsr04.ko
 +
</syntaxhighlight>
 +
 
 +
Start the matrix-ultrasonic_ranger program.<br>
 +
<syntaxhighlight lang="bash">
 +
$ matrix-ultrasonic_ranger
 +
</syntaxhighlight>
 +
 
 +
Here is what you expect to observe:<br>
 +
[[File:matrix-ultrasonic_ranger_result.png|frameless|600px|matrix-ultrasonic_ranger_result]]
 +
 
 +
===Code Sample===
 +
<syntaxhighlight lang="c">
 +
int main(int argc, char ** argv)
 +
{
 +
    int distance = -1;
 +
    int pin = GPIO_PIN(7);
 +
 
 +
    if (Hcsr04Init(pin) == -1) {
 +
        printf("Fail to init hcsr04\n");
 +
    }
 +
    if (Hcsr04Read(&distance) != -1) {
 +
        printf("Get distance: %3d cm\n", distance);
 +
    } else {
 +
        printf("Faid to get distance\n");
 +
    }
 +
    Hcsr04DeInit();
 +
    return 0;
 +
}
 
</syntaxhighlight>
 
</syntaxhighlight>
−
克隆完成后会得到一个matrix目录，里面存放着所有Matrix配件的代码。
 
  
−
==与NanoPi连接使用==
+
==Connect to NanoPi==
−
===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]] <br>
+
Please install a Debian on a NanoPi and an appropriate cross compiler on a PC. Please refer to wiki: [[NanoPi/zh|NanoPi]] <br>
−
注意：必须使用nanopi-v4.1.y-matrix分支编译出来的内核。<br>
+
Compile a NanoPi kernel. Note: please use the kernel's source code from the nanopi-v4.1.y-matrix branch. <br>
−
下载NanoPi内核源代码并编译
+
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ git clone https://github.com/friendlyarm/linux-4.x.y.git
 
$ git clone https://github.com/friendlyarm/linux-4.x.y.git
Line 62: Line 266:
  
  
−
===硬件连接===
+
===Hardware Connection===
−
参考下图连接模块Matrix-Ultrasonic_Ranger和NanoPi <br>
+
Please refer to the following connection diagram to connect the Matrix-Ultrasonic_Ranger to the NanoPi <br>
 
[[File:ur&NanoPi.png|frameless|400px|NanoPi+ur]]
 
[[File:ur&NanoPi.png|frameless|400px|NanoPi+ur]]
  
−
连接说明：
+
Connection Details:
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
Line 78: Line 282:
 
|}
 
|}
  
−
===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 nanopi branch
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ cd matrix
 
$ cd matrix
Line 85: Line 289:
 
</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 91: Line 295:
 
$ 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-Debian配套的arm-linux-gcc-4.4.3。<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-Ultrasonic_Ranger对应的测试程序为matrix-ultrasonic_ranger。<br>
+
Generated library files are under the "install/lib" directory. Applications are under the "install/usr/bin" directory. The test program for the "Matrix-Ultrasonic_Ranger" module is "matrix-ultrasonic_ranger".<br>
  
−
===运行测试程序===
+
===Run Test Program===
−
拷贝库文件和测试程序到NanoPi的文件系统上
+
Please copy the library files and test program to the NanoPi
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ cp install/usr/bin/* nanopi_rootfs/usr/bin/
 
$ cp install/usr/bin/* nanopi_rootfs/usr/bin/
Line 101: Line 305:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
然后启动NanoPi，在Debian的shell终端中执行如下命令运行模块Matrix-Ultrasonic_Ranger的测试程序 <br>
+
Power on the NanoPi and run the following command in Debian's terminal <br>
−
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。
+
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-ultrasonic_ranger
 
$ matrix-ultrasonic_ranger
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
===代码展示===
+
===Code Sample===
 
<syntaxhighlight lang="c">
 
<syntaxhighlight lang="c">
 
int main(int argc, char ** argv)
 
int main(int argc, char ** argv)
Line 128: Line 332:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
==与Tiny4412连接使用==
+
==Connect to Tiny4412==
−
===准备工作===
+
===Preparations===
−
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>
+
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：只能使用Tiny4412SDK-1506的底板。
+
Note: only the Tiny4412SDK-1506 carrier board can work with this module.
  
−
===硬件连接===
+
===Hardware Connection===
−
参考下图连接模块Matrix-Ultrasonic_Ranger和Tiny4412 <br>
+
Please refer to the following diagram to connect the Matrix-Ultrasonic_Ranger to the Tiny4412 <br>
 
[[File:ur&tiny4412.png|frameless|400px|tiny4412+ur]]
 
[[File:ur&tiny4412.png|frameless|400px|tiny4412+ur]]
 
<br>
 
<br>
−
连接说明：
+
Connection Details:
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
Line 149: Line 353:
 
|}
 
|}
  
−
===编译测试程序===
+
===Compile Test Program===
−
进入Matrix代码仓库，切换到tiny4412分支
+
Please login the Matrix hub and enter the matrix-tiny4412 branch
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ cd matrix
 
$ cd matrix
Line 156: Line 360:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
编译Matrix配件代码
+
Compile the matrix code
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ make CROSS_COMPILE=arm-linux-gnueabihf- clean
 
$ make CROSS_COMPILE=arm-linux-gnueabihf- clean
Line 162: Line 366:
 
$ make CROSS_COMPILE=arm-linux-gnueabihf- 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Tiny4412-UbuntuCore配套的arm-linux-gnueabihf-gcc-4.7.3。<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-Ultrasonic_Ranger对应的测试程序为matrix-ultrasonic_ranger。
+
Generated library files are under the "install/lib" directory. Applications are under the "install/usr/bin" directory. The test program for the "Matrix-Ultrasonic_Ranger" module is "matrix-ultrasonic_ranger".
  
−
===运行测试程序===
+
===Run Test Program===
−
拷贝库文件和测试程序到Tiny4412的UbuntuCore的文件系统上
+
Please copy the library files and test program to the Tiny4412
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ cp install/usr/bin/* tiny4412_rootfs/usr/bin/
 
$ cp install/usr/bin/* tiny4412_rootfs/usr/bin/
Line 172: Line 376:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
然后启动Tiny4412，在UbuntuCore的shell终端中执行如下命令运行模块Matrix-Ultrasonic_Ranger的测试程序 <br>
+
Power on the Tiny4412 and run the following command in UbuntuCore's terminal <br>
−
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。
+
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-ultrasonic_ranger
 
$ matrix-ultrasonic_ranger
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
===代码展示===
+
===Code Sample===
 
<syntaxhighlight lang="c">
 
<syntaxhighlight lang="c">
 
int main(int argc, char ** argv)
 
int main(int argc, char ** argv)
Line 199: Line 403:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
==与RaspberryPi连接使用==
+
==Connect to RaspberryPi==
−
 
+
−
==与Arduino连接使用==
+
−
 
+
−
==相关资料==
+
  
 +
==Connect to Arduino==
 +
--->
 +
==Resources==
  
 +
==Update Log==
 +
===Feb-23-2016===
 +
* Added the description for "NanoPi 2 branch" in Section 4
 +
* Added Section 5: Connect to NanoPi 2
 +
===June-28-2016===
 +
* Reorganized and simplified wiki
 
<!--
 
<!--
  

Latest revision as of 13:56, 28 June 2016

查看中文

1 Introduction

Ultrasonic Ranger01
  • The Matrix-Ultrasonic_Ranger is used to measure the distance.
  • The module's sensor emits a sound wave, which bounces off a reflective surface and returns to the sensor. Then, using the amount of time it takes for the wave to return to the sensor, the distance to the object can be computed.

2 Features

  • 5V Power
  • Range: 5 cm - 300 cm，Accuracy: 1 cm
  • One wire gpio
  • PCB Dimension (mm): 20 x 40

超声波PCB

  • Pin Description:
Pin Description
S GPIO
V Supply Voltage 5V
G Ground

3 Basic Device Operation

  • The sensor emits a 40kHz, 6 mm sound wave, which bounces off a reflective surface and returns to the sensor. The receiver converts ultrasound waves to electrical signals in mV.
  • The master sends a signal to the module starting to emit a sound wave. After the module receives the returned signal it will will generate a high level indicating the elapsed time and the distance will be calculated by distance = (elapsed time * speed of sound)/2.
matrix Ultrasonic Ranger

4 Applications

4.1 Connect to NanoPi M1

Refer to the following connection diagram to connect the module to the NanoPi M1:
Matrix-Ultrasonic_Ranger_nanopi_m1

Connection Details:

Matrix-Ultrasonic_Ranger NanoPi M1
S Pin7
V Pin4
G Pin6

4.2 Connect to NanoPi 2

Refer to the following connection diagram to connect the module to the NanoPi 2:
Matrix-Ultrasonic_Ranger_nanopi_2

Connection Details:

Matrix-Ultrasonic_Ranger NanoPi 2
S Pin7
V Pin4
G Pin6

4.3 Connect to NanoPi M2 / NanoPi 2 Fire

Refer to the following connection diagram to connect the module to the NanoPi M2/ NanoPi 2 Fire:
Matrix-Ultrasonic_Ranger_nanopi_m2

Connection Details:

Matrix-Ultrasonic_Ranger NanoPi M2
S Pin7
V Pin4
G Pin6

4.4 Connect to NanoPC-T2

Refer to the following connection diagram to connect the module to the NanoPC-T2:
Matrix-Ultrasonic_Ranger_NanoPC-T2

Connection Details:

Matrix-Ultrasonic_Ranger NanoPC-T2
S Pin15
V Pin29
G Pin30

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-ultrasonic_ranger

Note: 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 distance is  24 cm

When you place an object in front of the module the distance between the object and the module will be measured and printed.

6 Code Sample

This Matrix code sample can work with all the ARM boards mentioned in this module's wiki. The name of this code sample is "matrix-ultrasonic_ranger". Here is its source code: 

int main(int argc, char ** argv)
{
    int distance = -1;
    int pin = GPIO_PIN(7);
    int board;
 
    if ((board = boardInit()) < 0) {
        printf("Fail to init board\n");
        return -1;
    }
    if (board == BOARD_NANOPI_T2)
        pin = GPIO_PIN(15);
 
    system("modprobe "DRIVER_MODULE);
    if (Hcsr04Init(pin) == -1) {
        printf("Fail to init hcsr04\n");
        goto err;
    }
    if (Hcsr04Read(&distance) != -1) {
        printf("The distance is %3d cm\n", distance);
    } else {
        printf("Faid to get distance\n");
    }
    Hcsr04DeInit();
err:
    system("rmmod "DRIVER_MODULE);
 
    return 0;
}

For more details about this APIs called in this code sample refer to Matrix API reference manual

7 Resources

8 Update Log

8.1 Feb-23-2016

  • Added the description for "NanoPi 2 branch" in Section 4
  • Added Section 5: Connect to NanoPi 2

8.2 June-28-2016

  • Reorganized and simplified wiki
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