Difference between revisions of "Matrix - Potentiometer"

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(硬件连接)
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==硬件连接==
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==Applications==
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>
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The Matrix-Potentiometer module outputs analog signals which can be converted to digital signals through an ADC converter e.g. the Matrix-Analog_to_Digital_Converter module.<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>
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For more details about the Matrix-Analog_to_Digital_Converter module refer to wiki:[[Matrix_-_Analog_to_Digital_Converter/zh|Matrix-Analog_to_Digital_Converter]]。<br>
  
===连接NanoPi M1===
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===Connect to NanoPi M1===
参考下图连接模块:<br>
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Refer to the following connection diagram to connect the module to the NanoPi M1:<br>
 
[[File:Matrix-Potentiometer_nanopi_m1.jpg|frameless|600px|Matrix-Potentiometer_nanopi_m1]]
 
[[File:Matrix-Potentiometer_nanopi_m1.jpg|frameless|600px|Matrix-Potentiometer_nanopi_m1]]
  
连接说明:
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Connection Details:
 
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===连接NanoPi 2===
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===Connect to NanoPi 2===
参考下图连接模块:<br>
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Refer to the following connection diagram to connect the module to the NanoPi 2:<br>
 
[[File:Matrix-Potentiometer.jpg|frameless|600px|Matrix-Potentiometer]]
 
[[File:Matrix-Potentiometer.jpg|frameless|600px|Matrix-Potentiometer]]
  
连接说明:
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Connection Details:
 
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===连接NanoPi M2 / NanoPi 2 Fire===
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===Connect to 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>
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Refer to the following connection diagram to connect the module to the NanoPi M2/ NanoPi 2 Fire.<br>
参考下图连接模块:<br>
+
 
[[File:Matrix-Potentiometer_nanopi_m2.jpg|frameless|600px|Matrix-Potentiometer_nanopi_m2]]
 
[[File:Matrix-Potentiometer_nanopi_m2.jpg|frameless|600px|Matrix-Potentiometer_nanopi_m2]]
  
连接说明:
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Connection Details:
 
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===连接NanoPC-T2===
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===Connect to NanoPC-T2===
参考下图连接模块:<br>
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Refer to the following connection diagram to connect the module to the NanoPC-T2:<br>
 
[[File:Matrix-Potentiometer_NanoPC-T2.jpg|frameless|600px|Matrix-Potentiometer_NanoPC-T2]]
 
[[File:Matrix-Potentiometer_NanoPC-T2.jpg|frameless|600px|Matrix-Potentiometer_NanoPC-T2]]
  
连接说明:
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Connection Details:
 
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Revision as of 14:20, 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 Applications

The Matrix-Potentiometer module outputs analog signals which can be converted to digital signals through an ADC converter e.g. the Matrix-Analog_to_Digital_Converter module.
For more details about the Matrix-Analog_to_Digital_Converter module refer to wiki:Matrix-Analog_to_Digital_Converter

4.1 Connect to NanoPi M1

Refer to the following connection diagram to connect the module to the NanoPi M1:
Matrix-Potentiometer_nanopi_m1

Connection Details:

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

4.2 Connect to NanoPi 2

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

Connection Details:

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

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-Potentiometer_nanopi_m2

Connection Details:

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

4.4 Connect to NanoPC-T2

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

Connection Details:

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