Randomized stop and start (#18)

* added random delay for start and stop

* docs night-n-day

README.md

@@ -26,7 +26,7 @@ E.g. Thonny or VSCode.
 For lookenspeepers, build this project and watschen der Blinkenlichten!
 
 - Wire up your RaspberryPi Pico according to the Fritzing diagram
-- Optionally remove the resistor on GPIO2 to use an 8 minutes day/night cycle
+- (optional: ground GPIO2 with a resistor to bypass the 8 minutes day/night cycle and be 'always on')
 - Save the script 'slag-in-de-rondte.py' to your Pico as 'main.py'
 - Restart your Pico
 
@@ -61,16 +61,16 @@ Tip: check for MicroPython linting
 ## Parts, wiring, pinout
 
 | item                  | quantity |
-| ---                   | --- |
-| RaspberryPi Pico H    | 1 |
-| LED white (5mm)       | 5 |
-| LED red   (5mm)       | 1 |
-| LED green (5mm)       | 1 |
-| resistor 1kΩ          | 7 |
-| breadboard            | 1 |
-| hollow pipe tool 4mm  | 1 |
-
-An [RPI Pico](https://www.raspberrypi.com/documentation/microcontrollers/raspberry-pi-pico.html)
+| ---                   | ---      |
+| RaspberryPi Pico H    | 1        |
+| LED white (5mm)       | 5        |
+| LED red   (5mm)       | 1        |
+| LED green (5mm)       | 1        |
+| resistor 1kΩ          | 7        |
+| breadboard            | 1        |
+| hollow pipe tool 4mm  | 1        |
+
+A [RPI Pico](https://www.raspberrypi.com/documentation/microcontrollers/raspberry-pi-pico.html)
 costs about €6.- at [Kiwi](https://www.kiwi-electronics.com/nl/raspberry-pi-pico-h-10939),
 a breadboard (400 points) costs about €4.-.  
 A hollow pipe tool (Dutch: holpijp) is only needed if you want to punch holes in your game board, to fit the LEDs.  
@@ -82,7 +82,7 @@ A hollow pipe tool (Dutch: holpijp) is only needed if you want to punch holes in
 | pin | pin name | in/out   | description                  |
 | --- | ---      | ---      | ---                          |
 |  3  | GND      |          | ground                       |
-|  4  | GPIO 2   | in       | disables night and day cycle |
+|  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             |

slag-in-de-rondte.py

@@ -14,6 +14,7 @@
 from time import sleep
 import gc
 import math
+import random
 import time
 import uasyncio
 
@@ -32,7 +33,7 @@
 #  - pin grounded     = continuously use LEDs 
 night_n_day     = Pin(2, Pin.IN, Pin.PULL_UP)
 
-# Coroutine: Flash a LED, once
+# Coroutine
 async def flash(pwm):
   """Fade a LED on and off, using Pulse Width Modulation
 
@@ -60,7 +61,7 @@ async def flash(pwm):
   pwm.duty_u16(0)
   await uasyncio.sleep_ms(1600)
 
-# Corouting: Isophase a LED
+# Coroutine
 async def isophase(pwm, d):
   """Isophase a LED on and off, using Pulse Width Modulation
 
@@ -91,9 +92,10 @@ async def isophase(pwm, d):
   pwm.duty_u16(0)
   await uasyncio.sleep_ms(round(d/2) * 1000)
 
-# Corouting: Fade out a LED, to stop a cycle for the day
+# Coroutine
 async def fade_out(pwm):
-
+  """Fade out a LED, to stop the current task
+  """
   # Get the current duty cycle and fade out from there.
   current_duty_cycle = pwm.duty_u16()
   current_duty_cycle_fraction = (current_duty_cycle // (duty_max/100))
@@ -104,8 +106,18 @@ async def fade_out(pwm):
     await uasyncio.sleep_ms(12)
   pwm.duty_u16(0)  
 
+# Coroutine
+async def random_delay():
+  """Random delay of at most 5 seconds
+  """
+  max_msec = 5000
+  delay_ms = math.floor(random.random() * max_msec)
+  await uasyncio.sleep_ms(delay_ms)
+
 # Coroutine: characteristics of light: Texel FL(2) W 10s
 async def characteristics_texel(texel):
+  await random_delay()
+
   while True:
     try:
       time_begin = time.ticks_ms()
@@ -115,25 +127,33 @@ async def characteristics_texel(texel):
       await uasyncio.sleep_ms(10000 - time_elapsed)
 
     except (uasyncio.CancelledError):
+      await random_delay()
+
       # Switch off
       await fade_out(texel)
       print('Task Texel cancelled')
       raise
 
 # Coroutine: characteristics of light: Vlieland ISO W 4s
 async def characteristics_vlieland(vlieland):
+  await random_delay()
+
   while True:
     try:
       await isophase(vlieland, 4)
 
     except (uasyncio.CancelledError):
+      await random_delay()
+
       # Switch off
       await fade_out(vlieland)
       print('Task Vlieland cancelled')
       raise
 
 # Coroutine: characteristics of light: Terschelling FL(1) W 5s
 async def characteristics_terschelling(terschelling):
+  await random_delay()
+
   while True:
     try:
       time_begin = time.ticks_ms()
@@ -142,13 +162,17 @@ async def characteristics_terschelling(terschelling):
       await uasyncio.sleep_ms(5000 - time_elapsed)
 
     except (uasyncio.CancelledError):
+      await random_delay()
+
       # Switch off
       await fade_out(terschelling)
       print('Task Terschelling cancelled')
       raise
 
 #Coroutine: characteristics of light: Ameland FL(3) W 15s
 async def characteristics_ameland(ameland):
+  await random_delay()
+
   while True:
     try:
       time_begin = time.ticks_ms()
@@ -159,13 +183,17 @@ async def characteristics_ameland(ameland):
       await uasyncio.sleep_ms(15000 - time_elapsed)
 
     except (uasyncio.CancelledError):
+      await random_delay()
+
       # Switch off
       await fade_out(ameland)
       print('Task Ameland cancelled')
       raise
 
 # Coroutine: characteristics of light: Schiermonnikoog FL(4) W 20s
 async def characteristics_schiermonnikoog(schiermonnikoog):
+  await random_delay()
+
   while True:
     try:
       time_begin = time.ticks_ms()
@@ -177,6 +205,8 @@ async def characteristics_schiermonnikoog(schiermonnikoog):
       await uasyncio.sleep_ms(20000 - time_elapsed)
 
     except (uasyncio.CancelledError):
+      await random_delay()
+
       # Switch off
       await fade_out(schiermonnikoog)
       print('Task Schiermonnikoog cancelled')