diff --git a/README.md b/README.md
index 22a1e20..d7e3fb3 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,8 @@ E.g. Thonny or VSCode.
 
 For lookenspeepers, build this project and watschen der Blinkenlichten!
 
-- Wire up your RaspberryPi Pico according to the Fritzing diagram.
+- Wire up your RaspberryPi Pico according to the Fritzing diagram
+- Optionally remove the resistor on GPIO2 to use an 8 minutes day/night cycle
 - Save the script 'slag-in-de-rondte.py' to your Pico as 'main.py'
 - Restart your Pico
 
@@ -78,16 +79,16 @@ A hollow pipe tool (Dutch: holpijp) is only needed if you want to punch holes in
 
 ![Hollow pipe tool](/img/holpijp.png)
 
-| pin | pin name | in/out   | description         |
-| --- | ---      | ---      | ---                 |
-|  3  | GND      |          | ground              |
-|  4  | GPIO 2   | in       | (future use)        |
-| 21  | GPIO 16  | out 3.3V | LED Texel           |
-| 22  | GPIO 17  | out 3.3V | LED Vlieland        |
-| 24  | GPIO 18  | out 3.3V | LED Terschelling    |
-| 25  | GPIO 19  | out 3.3V | LED Ameland         |
-| 26  | GPIO 20  | out 3.3V | LED Schiermonnikoog |
-| 39  | VSYS     | 5V       | LED Red + Green Harlingen |
+| pin | pin name | in/out   | description                  |
+| --- | ---      | ---      | ---                          |
+|  3  | GND      |          | ground                       |
+|  4  | GPIO 2   | in       | disables night and day cycle |
+| 21  | GPIO 16  | out 3.3V | LED Texel                    |
+| 22  | GPIO 17  | out 3.3V | LED Vlieland                 |
+| 24  | GPIO 18  | out 3.3V | LED Terschelling             |
+| 25  | GPIO 19  | out 3.3V | LED Ameland                  |
+| 26  | GPIO 20  | out 3.3V | LED Schiermonnikoog          |
+| 39  | VSYS     | 5V       | LED Red + Green Harlingen    |
 
 CAUTION:
 Drawing too much power from the board may damage the board.  
diff --git a/slag-in-de-rondte.py b/slag-in-de-rondte.py
index 63c1de4..e3be4cd 100644
--- a/slag-in-de-rondte.py
+++ b/slag-in-de-rondte.py
@@ -27,11 +27,10 @@
 ameland         = PWM(Pin(19), f)
 schiermonnikoog = PWM(Pin(20), f)
 
-# WIP: Optionally, run without day&night cycle
-always_on       = Pin(2, Pin.IN)
-
-# Optionally, grab the temperature of your board
-adc = machine.ADC(4)
+# Optionally, run without night_n_day cycle
+#  - pin not grounded = night and day cycle of 8 minutes
+#  - pin grounded     = continuously use LEDs 
+night_n_day     = Pin(2, Pin.IN, Pin.PULL_UP)
 
 # Coroutine: Flash a LED, once
 async def flash(pwm):
@@ -92,7 +91,7 @@ async def isophase(pwm, d):
   pwm.duty_u16(0)
   await uasyncio.sleep_ms(round(d/2) * 1000)
 
-# Corouting: Fade out a LED
+# Corouting: Fade out a LED, to stop a cycle for the day
 async def fade_out(pwm):
 
   # Get the current duty cycle and fade out from there.
@@ -189,46 +188,49 @@ async def main():
   # Half a day contains roughly a tidal cycle, high water + low water
   # In the board game this cycle takes 8 minutes (480 seconds)
   tidal_cycle = 480
+
+  # Switch on all lighthouses (night)
+  lighthouses = [
+    uasyncio.create_task(characteristics_texel(texel)),
+    uasyncio.create_task(characteristics_vlieland(vlieland)),
+    uasyncio.create_task(characteristics_terschelling(terschelling)),
+    uasyncio.create_task(characteristics_ameland(ameland)),
+    uasyncio.create_task(characteristics_schiermonnikoog(schiermonnikoog))
+  ]
+
   while True:
-    
-    # A night of sailing starts. Switch on all five lighthouses
-    print('Night')
-    task_tx  = uasyncio.create_task(characteristics_texel(texel))
-    task_vl  = uasyncio.create_task(characteristics_vlieland(vlieland))
-    task_ts  = uasyncio.create_task(characteristics_terschelling(terschelling))
-    task_am  = uasyncio.create_task(characteristics_ameland(ameland))
-    task_sch = uasyncio.create_task(characteristics_schiermonnikoog(schiermonnikoog))
-    
+
     # Leave lighthouses on for the night
     await uasyncio.sleep(tidal_cycle)
     
-    # Is Pin4 grounded?
-    # WORK IN PROGRESS; this seems like a bad approach
-    if always_on == 0:
-      # pin is grounded
-      print('always on!')
+    # Enable night_n_day cycle? (is Pin grounded?)
+    if night_n_day.value() == 0:
+      print('pin grounded: no night_n_day')
+      continue
     else:
-      print('night & day')
-
-    # Print the temperature. (keep an eye on the board)
-    ADC_voltage = adc.read_u16() * (3.3/65536)
-    temp_celcius = 27 - (ADC_voltage - 0.706)/0.001721
-    print('Temperature: {}'.format(round(temp_celcius)))
+      print('pin not grounded: night_n_day')
 
     # After a night of sailing comes...  a day of sailing :)
     # Switch off all five lighthouses
-    print('Day')
-    task_tx.cancel()
-    task_vl.cancel()
-    task_ts.cancel()
-    task_am.cancel()
-    task_sch.cancel()
-    
+    print('day')
+    for task in lighthouses:
+      task.cancel()
+
     # Run the GC
     gc.collect()
 
-    ## Leave lighthouses off for the day
+    # Leave lighthouses off for the day
     await uasyncio.sleep(tidal_cycle)
 
+    # Switch the lighthouses on for the night
+    print('night')
+    lighthouses = [
+      uasyncio.create_task(characteristics_texel(texel)),
+      uasyncio.create_task(characteristics_vlieland(vlieland)),
+      uasyncio.create_task(characteristics_terschelling(terschelling)),
+      uasyncio.create_task(characteristics_ameland(ameland)),
+      uasyncio.create_task(characteristics_schiermonnikoog(schiermonnikoog))
+    ]
+
 # Start event loop
 uasyncio.run(main())
\ No newline at end of file