Difference between revisions of "Matrix - Potentiometer"
From FriendlyELEC WiKi
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| − | == | + | ==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.<br> | |
| − | + | 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> | |
| − | === | + | ===Connect to NanoPi M1=== |
| − | + | 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]] | ||
| − | + | Connection Details: | |
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| − | === | + | ===Connect to NanoPi 2=== |
| − | + | 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]] | ||
| − | + | Connection Details: | |
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| − | === | + | ===Connect to NanoPi M2 / NanoPi 2 Fire=== |
| − | NanoPi | + | Refer to the following connection diagram to connect the module to the NanoPi M2/ NanoPi 2 Fire.<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]] | ||
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| − | === | + | ===Connect to NanoPC-T2=== |
| − | + | 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]] | ||
| − | + | Connection Details: | |
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Revision as of 14:20, 23 June 2016
Contents
1 Introduction
- 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
- 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:
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:
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.
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 24606 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
