diff --git a/Hardware_control/timelapse.py b/Hardware_control/timelapse.py
index 0cb6660..b75fffe 100644
--- a/Hardware_control/timelapse.py
+++ b/Hardware_control/timelapse.py
@@ -1,39 +1,40 @@
-from picamera import PiCamera
-import RPi.GPIO as GPIO
-from time import sleep
-import time
-import datetime
 import os
 import sys
+import time
+import datetime
+
+from RPi import GPIO
 from shutil import copyfile
+from picamera import PiCamera
 
 GPIO.setmode(GPIO.BOARD)
 GPIO.setup(29, GPIO.OUT)
 
 camera = PiCamera()
 
-
 # Parameters for the user to modify
 # Basic settings
-if len(sys.argv)==5:
-    folder = str(sys.argv[1])            # e.g. Timelapse
-    filename = str(sys.argv[2])          # e.g. im_exp1
-    interval = int(sys.argv[3])     # wait time in seconds e.g. 1800
-    steps = int(sys.argv[4])        # number of images   e.g 200
+if len(sys.argv) == 5:
+    folder = str(sys.argv[1])   # e.g. Timelapse
+    filename = str(sys.argv[2]) # e.g. im_exp1
+    interval = int(sys.argv[3]) # wait time in seconds e.g. 1800
+    steps = int(sys.argv[4])    # number of images e.g 200
 else:
-    print ("Required parameters: folder name, filename, interval (secs), number of steps.")
+    print("Required parameters: folder name, filename, interval (secs), number of steps.")
     sys.exit()
     
-print('folder = ' + folder + '\nfilename = ' + filename +  
-      '\ninterval = ' + str(interval) + ' sec'+ '\nsteps = '+ str(steps))
+print(f'folder = {folder}')
+print(f'filename = {filename}')
+print(f'interval = {interval} sec')
+print(f'steps = {steps}')
  
 # make the folder if it doesn't exist
-if os.path.exists(folder) == False:
+if not os.path.exists(folder):
     os.mkdir(folder)
     
 # Minimal camera settings
-camera.resolution=(960,720)
-camera.ISO=400
+camera.resolution = (960,720)
+camera.ISO = 400
 camera.framerate = 1 # frames/sec, determines the max shutter speed
 camera.shutter_speed = 200000 # exposure time in microsecs
 camera.exposure_mode = 'off' #'fixedfps'
@@ -44,14 +45,14 @@
 # -------------------------------------------------------------
 # These are other possible parameters to change, depending on experiment:
 #camera.analog_gain = 1
-#camera.digital_gain=1
+#camera.digital_gain = 1
 #camera.brightness = 50
 #camera.sharpness = 0
 #camera.contrast = 0              # useful to take reduce the background
 #camera.saturation = 0
-#camera.exposure_compensation=0
-#camera.image_effect='none'
-#camera.color_effects=None
+#camera.exposure_compensation = 0
+#camera.image_effect = 'none'
+#camera.color_effects = None
 #camera.framerate = 0.01
 #camera.exposure_speed
 
@@ -64,26 +65,26 @@
 for i in range(steps):
     
     t1 = time.time()
-    print('Cycle ' + str(i))
+    print(f'Cycle {i}')
     
     # turn the LEDs on            
     GPIO.output(29,GPIO.HIGH)
 
     datestr = datetime.datetime.now().strftime("%Y-%m-%d-%H_%M_%S")
-    fname = os.path.join(folder, datestr + "_" + filename + "_%04d.jpg"%(i))
+    fname = os.path.join(folder, f'{datestr}_{filename}_{i:04}.jpg')
     camera.capture(fname)
     
-    #turn the LEDs off
+    # turn the LEDs off
     GPIO.output(29,GPIO.LOW)
 
-    elapsed = time.time()-t1
+    elapsed = time.time() - t1
 
     # print some relevant information
-    print('Elapsed cycle time: ' + str(elapsed))
-    print('Effective camera shutter speed :' + str(camera.shutter_speed) + '\n')
+    print(f'Elapsed cycle time: {elapsed}')
+    print(f'Effective camera shutter speed: {camera.shutter_speed} \n')
     # if the effective shutter speed doesnt coincide with the one you set,
     # you must modify the camera.framerate parameter.
     
-    sleep(interval-elapsed) ##  waiting time between cycles
+    time.sleep(interval-elapsed) ##  waiting time between cycles
     
 GPIO.cleanup()