Difference between revisions of "Matrix - Potentiometer"

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*This module mainly contains a potentiometer where the resistance changes with changes between the contact and one end terminal.
 
*This module mainly contains a potentiometer where the resistance changes with changes between the contact and one end terminal.
  
 +
 +
==硬件连接==
 +
模块Matrix-Potentiometer输出的是模拟信号，需要使用ADC转换模块Matrix-Analog_to_Digital_Converter将模拟信号转换为数字信号。<br>
 +
关于模块Matrix-Analog_to_Digital_Converter的使用方法可参考wiki：[[Matrix_-_Analog_to_Digital_Converter/zh|Matrix-Analog_to_Digital_Converter]]。<br>
 +
 +
===连接NanoPi M1===
 +
参考下图连接模块：<br>
 +
[[File:Matrix-Potentiometer_nanopi_m1.jpg|frameless|600px|Matrix-Potentiometer_nanopi_m1]]
 +
 +
连接说明：
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Potentiometer ||     
 +
|-
 +
|GND    || NanoPi M1 Pin9
 +
|-
 +
|5V    || NanoPi M1 Pin2
 +
|-
 +
|S      || Matrix-Analog_to_Digital_Converter A0
 +
|}
 +
 +
===连接NanoPi 2===
 +
参考下图连接模块：<br>
 +
[[File:Matrix-Potentiometer.jpg|frameless|600px|Matrix-Potentiometer]]
 +
 +
连接说明：
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Potentiometer ||     
 +
|-
 +
|GND    || NanoPi 2 Pin9
 +
|-
 +
|5V    || NanoPi 2 Pin2
 +
|-
 +
|S      || Matrix-Analog_to_Digital_Converter A0
 +
|}
 +
 +
===连接NanoPi M2 / NanoPi 2 Fire===
 +
NanoPi M2和NanoPi 2 Fire的40 Pin引脚定义是一模一样的，所以它们操作Matrix配件的步骤是一样的，这里仅以NanoPi M2为例。<br>
 +
参考下图连接模块：<br>
 +
[[File:Matrix-Potentiometer_nanopi_m2.jpg|frameless|600px|Matrix-Potentiometer_nanopi_m2]]
 +
 +
连接说明：
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Potentiometer ||     
 +
|-
 +
|GND    || NanoPi M2 Pin9
 +
|-
 +
|5V    || NanoPi M2 Pin2
 +
|-
 +
|S      || Matrix-Analog_to_Digital_Converter A0
 +
|}
 +
 +
===连接NanoPC-T2===
 +
参考下图连接模块：<br>
 +
[[File:Matrix-Potentiometer_NanoPC-T2.jpg|frameless|600px|Matrix-Potentiometer_NanoPC-T2]]
 +
 +
连接说明：
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Potentiometer ||     
 +
|-
 +
|GND    || NanoPC-T2 USB Host GND
 +
|-
 +
|5V    || NanoPC-T2 USB Host 5V
 +
|-
 +
|S      || Matrix-Analog_to_Digital_Converter A0
 +
|}
 +
 +
==编译运行测试程序==
 +
启动开发板并运行Debian系统，进入系统后克隆Matrix代码仓库：
 +
<syntaxhighlight lang="bash">
 +
$ apt-get update && apt-get install git
 +
$ git clone https://github.com/friendlyarm/matrix.git
 +
</syntaxhighlight>
 +
克隆完成后会得到一个名为matrix的目录。
 +
 +
编译并安装Matrix：
 +
<syntaxhighlight lang="bash">
 +
$ cd matrix
 +
$ make && make install
 +
</syntaxhighlight>
 +
 +
运行测试程序：
 +
<syntaxhighlight lang="bash">
 +
$ matrix-adc
 +
</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。<br>
 +
运行效果如下：<br>
 +
<syntaxhighlight lang="bash">
 +
The channel0 value is 2460
 +
</syntaxhighlight>
 +
 +
==代码说明==
 +
所有的开发板都共用一套Matrix代码，本模块的测试示例代码为matrix-analog_to_digital_converter，内容如下:
 +
<syntaxhighlight lang="c">
 +
int main(int argc, char ** argv)
 +
{
 +
    int i = 0;
 +
    int value = 0;
 +
    int channel = 0;
 +
 +
    if (boardInit() < 0) {
 +
        printf("Fail to init board\n");
 +
        return -1;
 +
    }
 +
   
 +
    if (argc == 2)
 +
        channel = atoi(argv[1]);
 +
    system("modprobe "DRIVER_MODULE);
 +
    signal(SIGINT, intHandler);
 +
    for (i=0; i<ADC_READ_TIMES; i++) {
 +
        if (pcf8591Read(channel, &value) != -1) {
 +
            printf("The channel%d value is %d\n", channel, value);
 +
        } else {
 +
            printf("Fail to get channel%d value\n", channel);
 +
        }
 +
    }
 +
    system("rmmod "DRIVER_MODULE);
 +
   
 +
    return 0;
 +
}
 +
</syntaxhighlight>
 +
API说明参考维基：[[Matrix API reference manual/zh|Matrix API reference manual]] <br>
 +
 +
==Resources==
 +
 +
<!---
 
==Download Matrix Source Code==
 
==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>
 
All the matrix modules' code samples are open source. They are maintained on GitHub :https://github.com/friendlyarm/matrix.git <br>
Line 145: Line 274:
 
}
 
}
 
</syntaxhighlight>
 
</syntaxhighlight>
 +
--->
  
 
==Update Log==
 
==Update Log==
 
===Feb-24-2016===
 
===Feb-24-2016===
 
* Added link to the Chinese version
 
* Added link to the Chinese version

Revision as of 14:10, 23 June 2016

查看中文

1 Introduction

Potentiometer
  • The Matrix-Potentiometer module is a Potentiometer module. It can be used in audio control, motion control, transducers, computation and etc.
  • 3 Pin 2.54mm spacing pin header, V is supply voltage, G is ground and S is output analog signal. Users can convert output analog signals to digital signals via ADC conversion.
  • Output Voltage: 0 ~ Vcc

2 Features

  • GPIO
  • Small
  • 2.54mm spacing pin header
  • PCB Dimension(mm): 8 x 24

Potentiometer_PCB

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

3 Basic Device Operation

  • A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider.If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat.
  • This module mainly contains a potentiometer where the resistance changes with changes between the contact and one end terminal.


4 硬件连接

模块Matrix-Potentiometer输出的是模拟信号，需要使用ADC转换模块Matrix-Analog_to_Digital_Converter将模拟信号转换为数字信号。
关于模块Matrix-Analog_to_Digital_Converter的使用方法可参考wiki：Matrix-Analog_to_Digital_Converter。

4.1 连接NanoPi M1

参考下图连接模块：
Matrix-Potentiometer_nanopi_m1

连接说明：

Matrix-Potentiometer
GND NanoPi M1 Pin9
5V NanoPi M1 Pin2
S Matrix-Analog_to_Digital_Converter A0

4.2 连接NanoPi 2

参考下图连接模块：
Matrix-Potentiometer

连接说明：

Matrix-Potentiometer
GND NanoPi 2 Pin9
5V NanoPi 2 Pin2
S Matrix-Analog_to_Digital_Converter A0

4.3 连接NanoPi M2 / NanoPi 2 Fire

NanoPi M2和NanoPi 2 Fire的40 Pin引脚定义是一模一样的，所以它们操作Matrix配件的步骤是一样的，这里仅以NanoPi M2为例。
参考下图连接模块：
Matrix-Potentiometer_nanopi_m2

连接说明：

Matrix-Potentiometer
GND NanoPi M2 Pin9
5V NanoPi M2 Pin2
S Matrix-Analog_to_Digital_Converter A0

4.4 连接NanoPC-T2

参考下图连接模块：
Matrix-Potentiometer_NanoPC-T2

连接说明：

Matrix-Potentiometer
GND NanoPC-T2 USB Host GND
5V NanoPC-T2 USB Host 5V
S Matrix-Analog_to_Digital_Converter A0

5 编译运行测试程序

启动开发板并运行Debian系统，进入系统后克隆Matrix代码仓库： 

$ apt-get update && apt-get install git
$ git clone https://github.com/friendlyarm/matrix.git

克隆完成后会得到一个名为matrix的目录。

编译并安装Matrix： 

$ cd matrix
$ make && make install

运行测试程序： 

$ matrix-adc

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。
运行效果如下：

The channel0 value is 2460

6 代码说明

所有的开发板都共用一套Matrix代码，本模块的测试示例代码为matrix-analog_to_digital_converter，内容如下: 

int main(int argc, char ** argv)
{
    int i = 0;
    int value = 0;
    int channel = 0;
 
    if (boardInit() < 0) {
        printf("Fail to init board\n");
        return -1;
    }
 
    if (argc == 2)
        channel = atoi(argv[1]);
    system("modprobe "DRIVER_MODULE);
    signal(SIGINT, intHandler);
    for (i=0; i<ADC_READ_TIMES; i++) {
        if (pcf8591Read(channel, &value) != -1) {
            printf("The channel%d value is %d\n", channel, value);
        } else {
            printf("Fail to get channel%d value\n", channel);
        }
    }
    system("rmmod "DRIVER_MODULE);
 
    return 0;
}

API说明参考维基：Matrix API reference manual

7 Resources

8 Update Log

8.1 Feb-24-2016

  • Added link to the Chinese version
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