LSL2joy/lsl2joy_continuous.py at master · conphyture/LSL2joy · GitHub

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from pylsl import StreamInlet, resolve_stream
import uinput, time

# map output to angles, continuous
# TODO: clamp input?
# TODO: command line parameters for some options
# TODO: propose transfer functions other than linear?

# how many seconds without samples should we wait before we timeout?
LSL_DECO_TIMEOUT=2

# we are not doing blocking call for LSL, but we don't want to use too much CPU either. Warning: if lower than input frequency, missed samples and/or shift will occur.
LSL_MAX_FREQ=1024

# stream name of classifier output in openvibe
stream_name = "hyperplane"

# one virtual joystick
events = (
    uinput.BTN_JOYSTICK,
    uinput.ABS_X + (0, 255, 0, 0),
    uinput.ABS_Y + (0, 255, 0, 0),
    )
device = uinput.Device(events)

# output range in X
X_MIN = 0
X_MAX = 255
# neutral position on start
X_CENTER = 128
Y_CENTER = 128

# center
device.emit(uinput.ABS_X, X_CENTER)
device.emit(uinput.ABS_Y, Y_CENTER)

inlet = None

# used to (re)connect to LSL
def lookout_stream():
    # first resolve an EEG stream on the lab network
    print("looking for LSL stream named [" + stream_name +"]")
    streams = resolve_stream('name', stream_name)

    # create a new inlet to read from the stream
    print("got it")
    return StreamInlet(streams[0])

while True:
    # connect / reco. NB: blocking call until one stream is found
    if inlet == None:
        inlet = lookout_stream()
        # init lsl for timeout detection
        last_sample = time.time()

    # get a new sample
    try:
        sample, timestamp = inlet.pull_sample(0)

    except:
        print "disconnected"
        inlet = None
        continue
    else:
        # check for time out and loop over if no sample
        if not sample:
            # let stream go and loop over if reached timeout
            time_since_last_sample = time.time() - last_sample
            if time_since_last_sample > LSL_DECO_TIMEOUT:
                print "time out"
                inlet = None
            # loop no matter what
            continue
        else:
            last_sample = time.time()
            print(timestamp, sample)


    # retrieve first channel
    value = sample[0]
    # convert to angle, from -1,1 to 0, 255
    joy_angle = int( (value + 1.)/2 * (X_MAX - X_MIN) ) + X_MIN
    if joy_angle < X_MIN:
        joy_angle = X_MIN
    if joy_angle > X_MAX:
        joy_angle = X_MAX
    print "output angle:", joy_angle
    device.emit(uinput.ABS_X, joy_angle)