During the loop execution of this example code, the infrared sensor tracks the LEGO® beacon as it’s moved from really close to the sensor to about 50 centimeters away. Then the beacon is moved from side to side, for about 50 centimeters as well.
Make sure the beacon is ON and on channel 1, and placed in front of the sensor before you run the example.
""" tracking.py Use the infrared sensor to track the LEGO beacon. Setup: Connect infrared sensor to port number 1. """ # Importing modules and classes import time import numpy as np from pyev3.utils import plot_line from pyev3.brick import LegoEV3 from pyev3.devices import Infrared # Defining parameters tstop = 20 # Execution loop duration (s) tsample = 0.02 # Data sampling period (s) tdisp = 0.2 # Screen display period (s) # Pre-allocating output arrays t =  azymuth =  proximity =  # Creating LEGO EV3 objects ev3 = LegoEV3() ired = Infrared(ev3, portnum=1, inputmode='seeker') # Initializing current time stamp and starting clock tprev = 0 tcurr = 0 tstart = time.perf_counter() # Changing EV3 status light ev3.set_statuslight(mode='pulsing') # Running execution loop print('Running for', tstop, 'seconds ...') while tcurr <= tstop: # Getting current azymuth and proximity (azymcurr, proxcurr) = ired.output # Updating previous time and getting current time (s) tprev = tcurr tcurr = time.perf_counter() - tstart # Displaying azymuth and proximity every `tdisp` seconds if (np.floor(tcurr/tdisp) - np.floor(tprev/tdisp)) == 1: print('Azymuth =', azymcurr, ', Proximity =', proxcurr) # Acquiring data every `tsample` seconds # and appending values to output arrays if (np.floor(tcurr/tsample) - np.floor(tprev/tsample)) == 1: t.append(tcurr) azymuth.append(azymcurr) proximity.append(proxcurr) print('Done.') # Closing brick connection ev3.set_statuslight(mode='solid') ev3.close() # Plotting results plot_line([t]*2, [azymuth, proximity], yname=['Azymuth ( - )', 'Proximity ( - )'], axes='multi')