JOY(4) MidnightBSD Kernel Interfaces Manual JOY(4)

NAME

joy — joystick device driver

SYNOPSIS

To compile this driver into the kernel, place the following lines in your kernel configuration file:

device joy

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

joy_load="YES"

In /boot/device.hints:

hint.joy.0.at="isa"
hint.joy.0.port="0x201"
hint.joy.1.at="isa"
hint.joy.1.port="0x201"

#include <sys/joystick.h>

DESCRIPTION

The joystick device driver allows applications to read the status of the PC joystick.

This device may be opened by only one process at a time.

The joystick status is read from a structure via a read() call. The structure is defined in the header file as follows:

struct joystick {

int x; /* x position */

int y; /* y position */

int b1;

/* button 1 status */

int b2;

/* button 2 status */

};

Positions are typically in the range 0-2000.

One line perl example:
perl -e ’open(JOY,"/dev/joy0")||die;while(1)
{sysread(JOY,$x,16);@j=unpack("iiii",$x);print "@j\n";sleep(1);}’

ioctl calls
Several ioctl() calls are also available. They take an argument of type int *

JOY_SETTIMEOUT int *limit

Set the time limit (in microseconds) for reading the joystick status. Setting a value too small may prevent to get correct values for the positions (which are then set to -2147483648), however this can be useful if one is only interested by the buttons status.

JOY_GETTIMEOUT int *limit

Get the time limit (in microseconds) used for reading the joystick status.

JOY_SET_X_OFFSET int *offset

Set the value to be added to the X position when reading the joystick status.

JOY_SET_Y_OFFSET int *offset

Set the value to be added to the Y position when reading the joystick status.

JOY_GET_X_OFFSET int *offset

Get the value which is added to the X position when reading the joystick status.

JOY_GET_Y_OFFSET int *offset

Get the value which is added to the Y position when reading the joystick status.

TECHNICAL SPECIFICATIONS

The pinout of the DB-15 connector is as follow:

1 XY1 (+5v)
2 Switch 1
3 X1 (potentiometer #1)
4 Switch 1 (GND)
5 Switch 2 (GND)
6 Y1 (potentiometer #2)
7 Switch 2
8 N.C.
9 XY2 (+5v)
10 Switch 4
11 X2 (potentiometer #3)
12 Switch 3&4 (GND)
13 Y2 (potentiometer #4)
14 Switch 3
15 N.C.

Pots are normally 0-150k variable resistors (0-100k sometimes), and according to the IBM technical reference, the time is given by Time = 24.2e-6s + 0.011e-6s * R/Ohms

FILES
/dev/joy?

joystick device files

HISTORY

The joy driver appeared in FreeBSD 2.0.5.

AUTHORS

Jean-Marc Zucconi 〈jmz@cabri.obs-besancon.fr〉

MidnightBSD 0.3 January 23, 1995 MidnightBSD 0.3