Add pinouts and refactor some code

Makefile

@@ -1,4 +1,5 @@
 copy:
 	ampy --port /dev/ttyUSB0 put code/boot.py
 	ampy --port /dev/ttyUSB0 put code/main.py
+	ampy --port /dev/ttyUSB0 put code/pinouts.py
 	ampy --port /dev/ttyUSB0 put code/hcsr04.py

code/main.py

@@ -1,19 +1,19 @@
-def blink():
-    import machine, time
+from pinouts import NodeMCU as pins
+from hcsr04 import HCSR04
+import time
+import machine
 
-    print("blink")
 
+def blink():
     pin = machine.Pin(2, machine.Pin.OUT)
 
     while True:
         pin.value(not pin.value())
         time.sleep_ms(500)
 
-def distance(trigger, echo):
-    from hcsr04 import HCSR04
-    import time
 
-    sensor = HCSR04(trigger_pin=trigger, echo_pin=echo)
+def distance():
+    sensor = HCSR04(trigger_pin=pins.D0, echo_pin=pins.D3)
 
     while True:
         print(sensor.distance_cm())

code/pinouts.py

@@ -0,0 +1,16 @@
+class NodeMCU:
+    """
+    Pinout mapping of the NODEMCU Board I've got.
+    """
+
+    D0  = 16
+    D1  = 5
+    D2  = 4
+    D3  = 0
+    D4  = 2
+    D5  = 14
+    D6  = 12
+    D7  = 13
+    D8  = 15
+    D9  = 3
+    D10 = 1