Matrix - Joystick

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Revision as of 07:07, 22 September 2015 by Yftan (Talk | contribs) (代码展示)

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1 Introduction

Joystick
  • 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

双轴摇杆PCB

  • Pin Description:
Pin Description
GND Ground
5V Power 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.
  • 为了更加方便地配合扩展板等标准接口,在设计上把 X,Y,Z 轴的电路都单独引出,以控制输入这个操纵杆模块的 x、y、z 的值以及在特定的值下实现某种功能。We extend all three outputs: X, Y and Z.

4 Download Matrix Source Code

All the matrix modules' code samples are open source. They are maintained on GitHub - git://github.com/friendlyarm/matrix.git
Each branch in this hub contains the matrix modules' code samples for a board that the matrix modules can work with.

  • The nanopi branch contains the matrix modules' code samples for the NanoPi
  • 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:
Install the git utility on a PC running Ubuntu14.04

$ sudo apt-get install git

Clone the matrix code from GitHub

$ git clone git://github.com/friendlyarm/matrix.git

If this is successful a "matrix" directory will be generated, which will contain all the matrix modules' code samples.

5 Connect to NanoPi

5.1 Preparations

Please install a Debian on a NanoPi and an appropriate cross compiler on a PC. Please refer to wiki: NanoPi
Compile a NanoPi kernel. Note: please use the kernel's source code from the nanopi-v4.1.y-matrix branch.

$ git clone https://github.com/friendlyarm/linux-4.x.y.git
$ cd linux-4.x.y
$ git checkout nanopi-v4.1.y-matrix
$ make nanopi_defconfig
$ touch .scmversion
$ make

5.2 Hardware Connection

Please refer to the following connection diagram to connect the Matrix-Joystick and Matrix-Analog_to_Digital_Converter to the NanoPi
matrix-joystick_nanopi

Connection Details:

Matrix-Joystick
GND NanoPi Pin14
5V NanoPi Pin2
SW Matrix-Analog_to_Digital_Converter A2
X Matrix-Analog_to_Digital_Converter A1
Y Matrix-Analog_to_Digital_Converter A0

5.3 Compile Test Program

Please login the matrix hub and enter the nanopi branch

$ cd matrix
$ git checkout nanopi

Compile the matrix code

$ make CROSS_COMPILE=arm-linux- clean
$ make CROSS_COMPILE=arm-linux-
$ make CROSS_COMPILE=arm-linux- install

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.
Generated library files are under the "install/lib" directory. Applications are under the "install/usr/bin" directory. The test program for the "Matrix-Joystick" module is "matrix-joystick".

5.4 Run Test Program

Please copy the library files and test program to the NanoPi

$ cp install/usr/bin/* nanopi_rootfs/usr/bin/
$ cp install/lib/* nanopi_rootfs/lib/ -d

Power on the NanoPi and run the following command in Debian's terminal

$ matrix-joystick

5.5 Code Sample

int main(int argc, char ** argv)
{
	int mode = 0x0;
 
	if ((devFD = pcf8591Init()) == -1) {
        printf("Fail to init pcf8591 AD\n");
        return -1;
    }
    if (pcf8591SetCtrl(devFD, PCF8591_INIT_AD_CONTROL) == -1) {
        printf("Fail to Set pcf8591 control AD\n");
        pcf8591DeInit(devFD);
        return -1;
    }
 
    int i = 0;
	int x, y, z;
	signal(SIGINT, PS2Handler);
	for (i=0; i<PS2_READ_TIMES; i++) {
		x = pcf8591Read(devFD, mode, PCF8591_AIN_CHANNEL0);
		y = pcf8591Read(devFD, mode, PCF8591_AIN_CHANNEL1);
		z = pcf8591Read(devFD, mode, PCF8591_AIN_CHANNEL2);
		if (z > SW_TRIGGER) {
			z = 0;
		} else {
			z = 1;
		}
		printf("X=%3d Y=%3d Z=%d\n", x, y, z);
		sleep(1);
	}
	pcf8591DeInit(devFD);
	return 0;
}

6 与Tiny4412连接使用

6.1 准备工作

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。
注意:只能使用Tiny4412SDK-1506的底板。

6.2 硬件连接

参考下图连接模块Matrix-Joystick、模块Matrix-Analog_to_Digital_Converter和Tiny4412
matrix-joystick_tiny4412

连接说明:

Matrix-Joystick
GND Tiny4412 CON16 GND
5V Tiny4412 CON16 5V
SW Matrix-Analog_to_Digital_Converter A2
X Matrix-Analog_to_Digital_Converter A1
Y Matrix-Analog_to_Digital_Converter A0

6.3 编译测试程序

进入matrix代码仓库,切换到tiny4412分支

$ cd matrix
$ git checkout tiny4412

编译Matrix配件代码

$ make CROSS_COMPILE=arm-linux-gnueabihf- clean
$ make CROSS_COMPILE=arm-linux-gnueabihf-
$ make CROSS_COMPILE=arm-linux-gnueabihf- install

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。
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-Joystick对应的测试程序为matrix-joystick。

6.4 运行测试程序

拷贝库文件和测试程序到Tiny4412的UbuntuCore的文件系统上

$ cp install/usr/bin/* tiny4412_rootfs/usr/bin/
$ cp install/lib/* tiny4412_rootfs/lib/ -d

然后启动Tiny4412,在UbuntuCore的shell终端中执行如下命令运行模块Matrix-Joystick的测试程序

$ matrix-joystick

6.5 代码展示

int main(int argc, char ** argv)
{
	int mode = 0x0;
 
	if ((devFD = pcf8591Init()) == -1) {
        printf("Fail to init pcf8591 AD\n");
        return -1;
    }
    if (pcf8591SetCtrl(devFD, PCF8591_INIT_AD_CONTROL) == -1) {
        printf("Fail to Set pcf8591 control AD\n");
        pcf8591DeInit(devFD);
        return -1;
    }
 
    int i = 0;
	int x, y, z;
	signal(SIGINT, PS2Handler);
	for (i=0; i<PS2_READ_TIMES; i++) {
		x = pcf8591Read(devFD, mode, PCF8591_AIN_CHANNEL0);
		y = pcf8591Read(devFD, mode, PCF8591_AIN_CHANNEL1);
		z = pcf8591Read(devFD, mode, PCF8591_AIN_CHANNEL2);
		if (z > SW_TRIGGER) {
			z = 0;
		} else {
			z = 1;
		}
		printf("X=%3d Y=%3d Z=%d\n", x, y, z);
		sleep(1);
	}
	pcf8591DeInit(devFD);
	return 0;
}

7 与RaspberryPi连接使用

8 与Arduino连接使用

9 相关资料