Matrix - Joystick
From FriendlyELEC WiKi
Contents
1 Introduction
- The matrix-joystick module is a two-axis stick module. It consists of two Sliding rheostats and one button. It has two analog outputs and one digital output. Its positional states can be measured as X and Y axis values as the calibrated resistance of the two potentiometers.
- When you move the joystick the sliding rheostats' resistance will change and the corresponding x/y values will change too. When you push the joystick the SW level will turn low.
2 Features
- X and Y axis, and one button
- 2.54mm spacing pin
- PCB dimension(mm): 24 X 32
- Pin Description:
Pin | Description |
GND | Ground |
5V | Supply Voltage 5V |
SW | Button |
X | X Axis |
Y | Y Axis |
3 Basic Device Operation
- It has two analog outputs and one digital output. The two analog outputs are measured as X and Y values as the calibrated resistance of the two potentiometers. The digital output is measured as Z value indicating whether or not the button is pressed.
- We extend all three outputs: X, Y and Z and users can use them easily.
4 硬件连接
模块Matrix-Joystick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
连接说明:
Matrix-Joystick | |
GND | NanoPi M1 Pin9 |
5V | NanoPi M1 Pin2 |
X | Matrix-Analog_to_Digital_Converter A1 |
Y | Matrix-Analog_to_Digital_Converter A2 |
4.2 连接NanoPi 2
连接说明:
Matrix-Joystick | |
GND | NanoPi 2 Pin9 |
5V | NanoPi 2 Pin2 |
X | Matrix-Analog_to_Digital_Converter A1 |
Y | Matrix-Analog_to_Digital_Converter A2 |
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_Joystick_nanopi_m2
连接说明:
Matrix-Joystick | |
GND | NanoPi M2 Pin9 |
5V | NanoPi M2 Pin2 |
X | Matrix-Analog_to_Digital_Converter A1 |
Y | Matrix-Analog_to_Digital_Converter A2 |
4.4 连接NanoPC-T2
参考下图连接模块:
Matrix_Joystick_NanoPC-T2
连接说明:
Matrix-Joystick | |
GND | NanoPC-T2 USB Host GND |
5V | NanoPC-T2 USB Host 5V |
X | Matrix-Analog_to_Digital_Converter A1 |
Y | Matrix-Analog_to_Digital_Converter A2 |
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-joystick
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:
x=1280 y=1280
拨动摇杆可以检测到x和y轴的变化。
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-joystick,内容如下:
int main(int argc, char ** argv) { int i = 0; int x, y, board; x = y = 0; if ((board = boardInit()) < 0) { printf("Fail to init board\n"); return -1; } system("modprobe "DRIVER_MODULE); signal(SIGINT, intHandler); for (i=0; i<PS2_READ_TIMES; i++) { if (pcf8591Read(1, &x) != -1 && pcf8591Read(2, &y) != -1) { printf("x=%4d y=%4d\n", x, y); } } 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-23-2016
- Added the description for "NanoPi 2 branch" in Section 4
- Added Section 5: Connect to NanoPi 2