joy(4)

NAME

joy - joystick device driver

SYNOPSIS

To link into the kernel:
device joy
To load as a kernel loadable module:
      kldload joy
In /boot/device.hints:
hint.joy.0.at="isa"
hint.joy.0.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

"@j0;sleep(1);}'

ioctl calls

Several ioctl() calls are also available. They take an ar

gument 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 posi

tion when reading the joystick status.

JOY_SET_Y_OFFSET int *offset

Set the value to be added to the Y posi

tion when reading the joystick status.

JOY_GET_X_OFFSET int *offset

Get the value which is added to the X po

sition when
reading the joystick status.

JOY_GET_Y_OFFSET int *offset

Get the value which is added to the Y po

sition 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 some

times), and
according to the IBM techref, the time is given by Time =

24.2e-6s +
0.011e-6s * R/Ohms

FILES

/dev/joy? joystick device files

HISTORY

The joystick driver appeared in FreeBSD 2.0.5.

AUTHORS

Jean-Marc Zucconi <jmz@cabri.obs-besancon.fr>

BSD January 23, 1995

BSD