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Access joysticks/game controllers from Python in Linux via the joystick driver. See https://discourse.panda3d.org/t/game-controllers-on-linux-without-pygame/14128
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# Released by rdb under the Unlicense (unlicense.org) | |
# Based on information from: | |
# https://www.kernel.org/doc/Documentation/input/joystick-api.txt | |
import os, struct, array | |
from fcntl import ioctl | |
# Iterate over the joystick devices. | |
print('Available devices:') | |
for fn in os.listdir('/dev/input'): | |
if fn.startswith('js'): | |
print(' /dev/input/%s' % (fn)) | |
# We'll store the states here. | |
axis_states = {} | |
button_states = {} | |
# These constants were borrowed from linux/input.h | |
axis_names = { | |
0x00 : 'x', | |
0x01 : 'y', | |
0x02 : 'z', | |
0x03 : 'rx', | |
0x04 : 'ry', | |
0x05 : 'rz', | |
0x06 : 'throttle', | |
0x07 : 'rudder', | |
0x08 : 'wheel', | |
0x09 : 'gas', | |
0x0a : 'brake', | |
0x10 : 'hat0x', | |
0x11 : 'hat0y', | |
0x12 : 'hat1x', | |
0x13 : 'hat1y', | |
0x14 : 'hat2x', | |
0x15 : 'hat2y', | |
0x16 : 'hat3x', | |
0x17 : 'hat3y', | |
0x18 : 'pressure', | |
0x19 : 'distance', | |
0x1a : 'tilt_x', | |
0x1b : 'tilt_y', | |
0x1c : 'tool_width', | |
0x20 : 'volume', | |
0x28 : 'misc', | |
} | |
button_names = { | |
0x120 : 'trigger', | |
0x121 : 'thumb', | |
0x122 : 'thumb2', | |
0x123 : 'top', | |
0x124 : 'top2', | |
0x125 : 'pinkie', | |
0x126 : 'base', | |
0x127 : 'base2', | |
0x128 : 'base3', | |
0x129 : 'base4', | |
0x12a : 'base5', | |
0x12b : 'base6', | |
0x12f : 'dead', | |
0x130 : 'a', | |
0x131 : 'b', | |
0x132 : 'c', | |
0x133 : 'x', | |
0x134 : 'y', | |
0x135 : 'z', | |
0x136 : 'tl', | |
0x137 : 'tr', | |
0x138 : 'tl2', | |
0x139 : 'tr2', | |
0x13a : 'select', | |
0x13b : 'start', | |
0x13c : 'mode', | |
0x13d : 'thumbl', | |
0x13e : 'thumbr', | |
0x220 : 'dpad_up', | |
0x221 : 'dpad_down', | |
0x222 : 'dpad_left', | |
0x223 : 'dpad_right', | |
# XBox 360 controller uses these codes. | |
0x2c0 : 'dpad_left', | |
0x2c1 : 'dpad_right', | |
0x2c2 : 'dpad_up', | |
0x2c3 : 'dpad_down', | |
} | |
axis_map = [] | |
button_map = [] | |
# Open the joystick device. | |
fn = '/dev/input/js0' | |
print('Opening %s...' % fn) | |
jsdev = open(fn, 'rb') | |
# Get the device name. | |
#buf = bytearray(63) | |
buf = array.array('B', [0] * 64) | |
ioctl(jsdev, 0x80006a13 + (0x10000 * len(buf)), buf) # JSIOCGNAME(len) | |
js_name = buf.tobytes().rstrip(b'\x00').decode('utf-8') | |
print('Device name: %s' % js_name) | |
# Get number of axes and buttons. | |
buf = array.array('B', [0]) | |
ioctl(jsdev, 0x80016a11, buf) # JSIOCGAXES | |
num_axes = buf[0] | |
buf = array.array('B', [0]) | |
ioctl(jsdev, 0x80016a12, buf) # JSIOCGBUTTONS | |
num_buttons = buf[0] | |
# Get the axis map. | |
buf = array.array('B', [0] * 0x40) | |
ioctl(jsdev, 0x80406a32, buf) # JSIOCGAXMAP | |
for axis in buf[:num_axes]: | |
axis_name = axis_names.get(axis, 'unknown(0x%02x)' % axis) | |
axis_map.append(axis_name) | |
axis_states[axis_name] = 0.0 | |
# Get the button map. | |
buf = array.array('H', [0] * 200) | |
ioctl(jsdev, 0x80406a34, buf) # JSIOCGBTNMAP | |
for btn in buf[:num_buttons]: | |
btn_name = button_names.get(btn, 'unknown(0x%03x)' % btn) | |
button_map.append(btn_name) | |
button_states[btn_name] = 0 | |
print('%d axes found: %s' % (num_axes, ', '.join(axis_map))) | |
print('%d buttons found: %s' % (num_buttons, ', '.join(button_map))) | |
# Main event loop | |
while True: | |
evbuf = jsdev.read(8) | |
if evbuf: | |
time, value, type, number = struct.unpack('IhBB', evbuf) | |
if type & 0x80: | |
print("(initial)", end="") | |
if type & 0x01: | |
button = button_map[number] | |
if button: | |
button_states[button] = value | |
if value: | |
print("%s pressed" % (button)) | |
else: | |
print("%s released" % (button)) | |
if type & 0x02: | |
axis = axis_map[number] | |
if axis: | |
fvalue = value / 32767.0 | |
axis_states[axis] = fvalue | |
print("%s: %.3f" % (axis, fvalue)) |
Hi, i want to control servo with a joystick by using a Raspberry Pi How can I take input from the joystick and give it to Servo?
basically controlling th servo through the joystick.
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I checked and instead of os.open there may be an easier alternative, by calling this on the file after the open call:
Of course you'll need to deal with the exception you will probably get when calling
read()
without data being available.