JOY(4) BSD Kernel Interfaces Manual JOY(4)NAMEjoy — 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 read‐
ing the joystick status.
JOY_SET_Y_OFFSET int *offset
Set the value to be added to the Y position when read‐
ing 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⟩
BSD January 23, 1995 BSD
