diff --git a/ch-5/4-pwm/with_helpers/robot.py b/ch-5/4-pwm/with_helpers/robot.py
index fbe0836..f1a9a2b 100755
--- a/ch-5/4-pwm/with_helpers/robot.py
+++ b/ch-5/4-pwm/with_helpers/robot.py
@@ -6,15 +6,17 @@ motor_A2 = pwmio.PWMOut(board.GP16)
 motor_B1 = pwmio.PWMOut(board.GP18)
 motor_B2 = pwmio.PWMOut(board.GP19)
 
+right_motor = motor_A1, motor_A2
+left_motor = motor_B1, motor_B2
+max_speed = 2**16-1
+
+
 def stop():
     motor_A1.duty_cycle = 0
     motor_A2.duty_cycle = 0
     motor_B1.duty_cycle = 0
     motor_B2.duty_cycle = 0
 
-max_speed = 2**16-1
-right_motor = motor_A1, motor_A2
-left_motor = motor_B1, motor_B2
 
 def set_speed(motor, speed):
     # Swap motor pins if we reverse the speed
@@ -28,8 +30,10 @@ def set_speed(motor, speed):
     direction[0].duty_cycle = int(max_speed * speed)
     direction[1].duty_cycle = 0
 
+
 def set_left(speed):
     set_speed(left_motor, speed)
 
+
 def set_right(speed):
-    set_speed(right_motor, speed)
\ No newline at end of file
+    set_speed(right_motor, speed)
diff --git a/ch-5/5-path/robot.py b/ch-5/5-path/robot.py
index 6c657ab..f1a9a2b 100755
--- a/ch-5/5-path/robot.py
+++ b/ch-5/5-path/robot.py
@@ -8,6 +8,8 @@ motor_B2 = pwmio.PWMOut(board.GP19)
 
 right_motor = motor_A1, motor_A2
 left_motor = motor_B1, motor_B2
+max_speed = 2**16-1
+
 
 def stop():
     motor_A1.duty_cycle = 0
@@ -15,6 +17,7 @@ def stop():
     motor_B1.duty_cycle = 0
     motor_B2.duty_cycle = 0
 
+
 def set_speed(motor, speed):
     # Swap motor pins if we reverse the speed
     if speed < 0:
@@ -23,14 +26,14 @@ def set_speed(motor, speed):
     else:
         direction = motor
     speed = min(speed, 1) # limit to 1.0
-    max_speed = 2**16-1
-
 
     direction[0].duty_cycle = int(max_speed * speed)
     direction[1].duty_cycle = 0
 
+
 def set_left(speed):
     set_speed(left_motor, speed)
 
+
 def set_right(speed):
     set_speed(right_motor, speed)