diff --git a/CircuitPython_Essentials/CircuitPython_AnalogIn.py b/CircuitPython_Essentials/CircuitPython_AnalogIn.py
index 8b2ed286b..722626a31 100644
--- a/CircuitPython_Essentials/CircuitPython_AnalogIn.py
+++ b/CircuitPython_Essentials/CircuitPython_AnalogIn.py
@@ -1,4 +1,4 @@
-# CircuitPython AnalogIn Demo
+"""CircuitPython Essentials Analog In example"""
 import time
 import board
 from analogio import AnalogIn
diff --git a/CircuitPython_Essentials/CircuitPython_AnalogOut.py b/CircuitPython_Essentials/CircuitPython_AnalogOut.py
index b5281c688..88a31fd39 100644
--- a/CircuitPython_Essentials/CircuitPython_AnalogOut.py
+++ b/CircuitPython_Essentials/CircuitPython_AnalogOut.py
@@ -1,4 +1,4 @@
-# CircuitPython IO demo - analog output
+"""CircuitPython Analog Out example"""
 import board
 from analogio import AnalogOut
 
diff --git a/CircuitPython_Essentials/CircuitPython_Audio_Out_MP3.py b/CircuitPython_Essentials/CircuitPython_Audio_Out_MP3.py
index 8d3b21535..b860b8481 100644
--- a/CircuitPython_Essentials/CircuitPython_Audio_Out_MP3.py
+++ b/CircuitPython_Essentials/CircuitPython_Audio_Out_MP3.py
@@ -1,3 +1,4 @@
+"""CircuitPython Essentials Audio Out MP3 Example"""
 import board
 import digitalio
 
diff --git a/CircuitPython_Essentials/CircuitPython_Audio_Out_Tone.py b/CircuitPython_Essentials/CircuitPython_Audio_Out_Tone.py
index 890c1e2d6..40de4c1f8 100644
--- a/CircuitPython_Essentials/CircuitPython_Audio_Out_Tone.py
+++ b/CircuitPython_Essentials/CircuitPython_Audio_Out_Tone.py
@@ -1,3 +1,4 @@
+"""CircuitPython Essentials Audio Out tone example"""
 import time
 import array
 import math
diff --git a/CircuitPython_Essentials/CircuitPython_Audio_Out_Wave.py b/CircuitPython_Essentials/CircuitPython_Audio_Out_Wave.py
index 24298ad55..99c8c3e7c 100644
--- a/CircuitPython_Essentials/CircuitPython_Audio_Out_Wave.py
+++ b/CircuitPython_Essentials/CircuitPython_Audio_Out_Wave.py
@@ -1,3 +1,4 @@
+"""CircuitPython Essentials Audio Out WAV example"""
 import time
 import board
 import digitalio
diff --git a/CircuitPython_Essentials/CircuitPython_CapTouch.py b/CircuitPython_Essentials/CircuitPython_CapTouch.py
index feaec0e20..d082d88f7 100644
--- a/CircuitPython_Essentials/CircuitPython_CapTouch.py
+++ b/CircuitPython_Essentials/CircuitPython_CapTouch.py
@@ -1,5 +1,5 @@
+"""CircuitPython Essentials Capacitive Touch example"""
 import time
-
 import board
 import touchio
 
diff --git a/CircuitPython_Essentials/CircuitPython_CapTouch_2Pins.py b/CircuitPython_Essentials/CircuitPython_CapTouch_2Pins.py
index fc9eafa67..e3e9159c3 100644
--- a/CircuitPython_Essentials/CircuitPython_CapTouch_2Pins.py
+++ b/CircuitPython_Essentials/CircuitPython_CapTouch_2Pins.py
@@ -1,8 +1,5 @@
-# CircuitPython Demo - Cap Touch Multiple Pins
-# Example does NOT work with Trinket M0!
-
+"""CircuitPython Essentials Capacitive Touch on two pins example. Does not work on Trinket M0!"""
 import time
-
 import board
 import touchio
 
diff --git a/CircuitPython_Essentials/CircuitPython_Continuous_Servo.py b/CircuitPython_Essentials/CircuitPython_Continuous_Servo.py
index 4622422f4..9240bbdb5 100644
--- a/CircuitPython_Essentials/CircuitPython_Continuous_Servo.py
+++ b/CircuitPython_Essentials/CircuitPython_Continuous_Servo.py
@@ -1,4 +1,4 @@
-# Continuous Servo Test Program for CircuitPython
+"""CircuitPython Essentials Servo continuous rotation servo example"""
 import time
 import board
 import pulseio
diff --git a/CircuitPython_Essentials/CircuitPython_Digital_In_Out.py b/CircuitPython_Essentials/CircuitPython_Digital_In_Out.py
index a8ef88605..6de582cf4 100644
--- a/CircuitPython_Essentials/CircuitPython_Digital_In_Out.py
+++ b/CircuitPython_Essentials/CircuitPython_Digital_In_Out.py
@@ -1,12 +1,15 @@
-# CircuitPython IO demo #1 - General Purpose I/O
+"""CircuitPython Essentials Digital In Out example"""
 import time
 import board
 from digitalio import DigitalInOut, Direction, Pull
 
+# LED setup.
 led = DigitalInOut(board.D13)
+# For QT Py M0. QT Py M0 does not have a D13 LED, so you can connect an external LED instead.
+# led = DigitalInOut(board.SCK)
 led.direction = Direction.OUTPUT
 
-# For Gemma M0, Trinket M0, Metro M0 Express, ItsyBitsy M0 Express, Itsy M4 Express
+# For Gemma M0, Trinket M0, Metro M0 Express, ItsyBitsy M0 Express, Itsy M4 Express, QT Py M0
 switch = DigitalInOut(board.D2)
 # switch = DigitalInOut(board.D5)  # For Feather M0 Express, Feather M4 Express
 # switch = DigitalInOut(board.D7)  # For Circuit Playground Express
diff --git a/CircuitPython_Essentials/CircuitPython_DotStar.py b/CircuitPython_Essentials/CircuitPython_DotStar.py
index 45c328469..14fe49b4b 100644
--- a/CircuitPython_Essentials/CircuitPython_DotStar.py
+++ b/CircuitPython_Essentials/CircuitPython_DotStar.py
@@ -1,4 +1,4 @@
-# CircuitPython demo - Dotstar
+"""CircuitPython Essentials DotStar example"""
 import time
 import adafruit_dotstar
 import board
@@ -7,7 +7,7 @@ num_pixels = 30
 pixels = adafruit_dotstar.DotStar(board.A1, board.A2, num_pixels, brightness=0.1, auto_write=False)
 
 
-def wheel(pos):
+def colorwheel(pos):
     # Input a value 0 to 255 to get a color value.
     # The colours are a transition r - g - b - back to r.
     if pos < 0 or pos > 255:
@@ -85,7 +85,7 @@ def rainbow_cycle(wait):
     for j in range(255):
         for i in range(num_pixels):
             rc_index = (i * 256 // num_pixels) + j
-            pixels[i] = wheel(rc_index & 255)
+            pixels[i] = colorwheel(rc_index & 255)
         pixels.show()
         time.sleep(wait)
 
diff --git a/CircuitPython_Essentials/CircuitPython_HID_Keyboard.py b/CircuitPython_Essentials/CircuitPython_HID_Keyboard.py
index 193be8c7a..de1aae4ca 100644
--- a/CircuitPython_Essentials/CircuitPython_HID_Keyboard.py
+++ b/CircuitPython_Essentials/CircuitPython_HID_Keyboard.py
@@ -1,5 +1,4 @@
-# CircuitPython demo - Keyboard emulator
-
+"""CircuitPython Essentials HID Keyboard example"""
 import time
 
 import board
@@ -31,7 +30,10 @@ for pin in keypress_pins:
     key_pin.pull = digitalio.Pull.UP
     key_pin_array.append(key_pin)
 
+# For most CircuitPython boards:
 led = digitalio.DigitalInOut(board.D13)
+# For QT Py M0:
+# led = digitalio.DigitalInOut(board.SCK)
 led.direction = digitalio.Direction.OUTPUT
 
 print("Waiting for key pin...")
diff --git a/CircuitPython_Essentials/CircuitPython_HID_Mouse.py b/CircuitPython_Essentials/CircuitPython_HID_Mouse.py
index 97476092d..398f4d1fb 100644
--- a/CircuitPython_Essentials/CircuitPython_HID_Mouse.py
+++ b/CircuitPython_Essentials/CircuitPython_HID_Mouse.py
@@ -1,5 +1,5 @@
+"""CircuitPython Essentials HID Mouse example"""
 import time
-
 import analogio
 import board
 import digitalio
diff --git a/CircuitPython_Essentials/CircuitPython_I2C_Scan.py b/CircuitPython_Essentials/CircuitPython_I2C_Scan.py
index 416a1c774..d75501380 100644
--- a/CircuitPython_Essentials/CircuitPython_I2C_Scan.py
+++ b/CircuitPython_Essentials/CircuitPython_I2C_Scan.py
@@ -1,9 +1,8 @@
-# CircuitPython demo - I2C scan
-# 
+"""CircuitPython Essentials I2C Scan example"""
 # If you run this and it seems to hang, try manually unlocking
 # your I2C bus from the REPL with
-#  >>> import board 
-#  >>> board.I2C().unlock() 
+#  >>> import board
+#  >>> board.I2C().unlock()
 
 import time
 import board
diff --git a/CircuitPython_Essentials/CircuitPython_I2C_TSL2561.py b/CircuitPython_Essentials/CircuitPython_I2C_TSL2591.py
similarity index 53%
rename from CircuitPython_Essentials/CircuitPython_I2C_TSL2561.py
rename to CircuitPython_Essentials/CircuitPython_I2C_TSL2591.py
index bd0a47e86..8c05ab39d 100644
--- a/CircuitPython_Essentials/CircuitPython_I2C_TSL2561.py
+++ b/CircuitPython_Essentials/CircuitPython_I2C_TSL2591.py
@@ -1,9 +1,7 @@
-# CircuitPython Demo - I2C sensor
-
+"""CircuitPython Essentials I2C sensor example using TSL2591"""
 import time
-
-import adafruit_tsl2561
 import board
+import adafruit_tsl2591
 
 i2c = board.I2C()
 
@@ -11,16 +9,15 @@ i2c = board.I2C()
 while not i2c.try_lock():
     pass
 # Print the addresses found once
-print("I2C addresses found:", [hex(device_address)
-                               for device_address in i2c.scan()])
+print("I2C addresses found:", [hex(device_address) for device_address in i2c.scan()])
 
 # Unlock I2C now that we're done scanning.
 i2c.unlock()
 
 # Create library object on our I2C port
-tsl2561 = adafruit_tsl2561.TSL2561(i2c)
+tsl2591 = adafruit_tsl2591.TSL2591(i2c)
 
 # Use the object to print the sensor readings
 while True:
-    print("Lux:", tsl2561.lux)
-    time.sleep(1.0)
+    print("Lux:", tsl2591.lux)
+    time.sleep(0.5)
diff --git a/CircuitPython_Essentials/CircuitPython_Internal_RGB_LED_colors.py b/CircuitPython_Essentials/CircuitPython_Internal_RGB_LED_colors.py
index 0d8028ce8..2f72fc5ba 100644
--- a/CircuitPython_Essentials/CircuitPython_Internal_RGB_LED_colors.py
+++ b/CircuitPython_Essentials/CircuitPython_Internal_RGB_LED_colors.py
@@ -1,10 +1,11 @@
+"""CircuitPython Essentials Internal RGB LED red, green, blue example"""
 import time
 import board
 
 # For Trinket M0, Gemma M0, ItsyBitsy M0 Express, and ItsyBitsy M4 Express
 import adafruit_dotstar
 led = adafruit_dotstar.DotStar(board.APA102_SCK, board.APA102_MOSI, 1)
-# For Feather M0 Express, Metro M0 Express, Metro M4 Express, and Circuit Playground Express
+# For Feather M0 Express, Metro M0 Express, Metro M4 Express, Circuit Playground Express, QT Py M0
 # import neopixel
 # led = neopixel.NeoPixel(board.NEOPIXEL, 1)
 
diff --git a/CircuitPython_Essentials/CircuitPython_Internal_RGB_LED_rainbow.py b/CircuitPython_Essentials/CircuitPython_Internal_RGB_LED_rainbow.py
index 339bd74d4..624cfec45 100644
--- a/CircuitPython_Essentials/CircuitPython_Internal_RGB_LED_rainbow.py
+++ b/CircuitPython_Essentials/CircuitPython_Internal_RGB_LED_rainbow.py
@@ -1,15 +1,16 @@
+"""CircuitPython Essentials Internal RGB LED rainbow example"""
 import time
 import board
 
 # For Trinket M0, Gemma M0, ItsyBitsy M0 Express and ItsyBitsy M4 Express
 import adafruit_dotstar
 led = adafruit_dotstar.DotStar(board.APA102_SCK, board.APA102_MOSI, 1)
-# For Feather M0 Express, Metro M0 Express, Metro M4 Express and Circuit Playground Express
+# For Feather M0 Express, Metro M0 Express, Metro M4 Express, Circuit Playground Express, QT Py M0
 # import neopixel
 # led = neopixel.NeoPixel(board.NEOPIXEL, 1)
 
 
-def wheel(pos):
+def colorwheel(pos):
     # Input a value 0 to 255 to get a color value.
     # The colours are a transition r - g - b - back to r.
     if pos < 0 or pos > 255:
@@ -28,5 +29,5 @@ led.brightness = 0.3
 i = 0
 while True:
     i = (i + 1) % 256  # run from 0 to 255
-    led.fill(wheel(i))
-    time.sleep(0.1)
+    led.fill(colorwheel(i))
+    time.sleep(0.01)
diff --git a/CircuitPython_Essentials/CircuitPython_Logger.py b/CircuitPython_Essentials/CircuitPython_Logger.py
index fe43400d7..0ea8ffa7f 100644
--- a/CircuitPython_Essentials/CircuitPython_Logger.py
+++ b/CircuitPython_Essentials/CircuitPython_Logger.py
@@ -1,10 +1,13 @@
+"""CircuitPython Essentials Storage logging example"""
 import time
-
 import board
 import digitalio
 import microcontroller
 
+# For most CircuitPython boards:
 led = digitalio.DigitalInOut(board.D13)
+# For QT Py M0:
+# led = digitalio.DigitalInOut(board.SCK)
 led.switch_to_output()
 
 try:
diff --git a/CircuitPython_Essentials/CircuitPython_Logger_Boot.py b/CircuitPython_Essentials/CircuitPython_Logger_Boot.py
index 128eb7242..98a0bb148 100644
--- a/CircuitPython_Essentials/CircuitPython_Logger_Boot.py
+++ b/CircuitPython_Essentials/CircuitPython_Logger_Boot.py
@@ -1,3 +1,4 @@
+"""CircuitPython Essentials Storage logging boot.py file"""
 import board
 import digitalio
 import storage
diff --git a/CircuitPython_Essentials/CircuitPython_NeoPixel.py b/CircuitPython_Essentials/CircuitPython_NeoPixel.py
index 9faf35589..2a300f563 100644
--- a/CircuitPython_Essentials/CircuitPython_NeoPixel.py
+++ b/CircuitPython_Essentials/CircuitPython_NeoPixel.py
@@ -1,4 +1,4 @@
-# CircuitPython demo - NeoPixel
+"""CircuitPython Essentials NeoPixel example"""
 import time
 import board
 import neopixel
diff --git a/CircuitPython_Essentials/CircuitPython_NeoPixel_RGBW.py b/CircuitPython_Essentials/CircuitPython_NeoPixel_RGBW.py
index 1b88a239b..4244651c1 100644
--- a/CircuitPython_Essentials/CircuitPython_NeoPixel_RGBW.py
+++ b/CircuitPython_Essentials/CircuitPython_NeoPixel_RGBW.py
@@ -1,5 +1,4 @@
-# CircuitPython demo - NeoPixel RGBW
-
+"""CircuitPython Essentials NeoPixel RGBW example"""
 import time
 import board
 import neopixel
diff --git a/CircuitPython_Essentials/CircuitPython_PWM.py b/CircuitPython_Essentials/CircuitPython_PWM.py
index 0fc9d01d4..beca87459 100644
--- a/CircuitPython_Essentials/CircuitPython_PWM.py
+++ b/CircuitPython_Essentials/CircuitPython_PWM.py
@@ -1,8 +1,12 @@
+"""CircuitPython Essentials: PWM with Fixed Frequency example."""
 import time
 import board
 import pulseio
 
+# LED setup for most CircuitPython boards:
 led = pulseio.PWMOut(board.D13, frequency=5000, duty_cycle=0)
+# LED setup for QT Py M0:
+# led = pulseio.PWMOut(board.SCK, frequency=5000, duty_cycle=0)
 
 while True:
     for i in range(100):
diff --git a/CircuitPython_Essentials/CircuitPython_PWM_Piezo.py b/CircuitPython_Essentials/CircuitPython_PWM_Piezo.py
index 83db44acd..2b15fbac2 100644
--- a/CircuitPython_Essentials/CircuitPython_PWM_Piezo.py
+++ b/CircuitPython_Essentials/CircuitPython_PWM_Piezo.py
@@ -1,3 +1,4 @@
+"""CircuitPython Essentials PWM with variable frequency piezo example"""
 import time
 import board
 import pulseio
diff --git a/CircuitPython_Essentials/CircuitPython_PWM_Piezo_simpleio.py b/CircuitPython_Essentials/CircuitPython_PWM_Piezo_simpleio.py
index 401cb317e..9228b784f 100644
--- a/CircuitPython_Essentials/CircuitPython_PWM_Piezo_simpleio.py
+++ b/CircuitPython_Essentials/CircuitPython_PWM_Piezo_simpleio.py
@@ -1,3 +1,4 @@
+"""CircuitPython Essentials PWM piezo simpleio example"""
 import time
 import board
 import simpleio
diff --git a/CircuitPython_Essentials/CircuitPython_Servo.py b/CircuitPython_Essentials/CircuitPython_Servo.py
index 835ff976b..3db9685a1 100644
--- a/CircuitPython_Essentials/CircuitPython_Servo.py
+++ b/CircuitPython_Essentials/CircuitPython_Servo.py
@@ -1,3 +1,4 @@
+"""CircuitPython Essentials Servo standard servo example"""
 import time
 import board
 import pulseio
diff --git a/CircuitPython_Essentials/CircuitPython_UART.py b/CircuitPython_Essentials/CircuitPython_UART.py
index c05e50dce..78381e69f 100644
--- a/CircuitPython_Essentials/CircuitPython_UART.py
+++ b/CircuitPython_Essentials/CircuitPython_UART.py
@@ -1,10 +1,12 @@
-# CircuitPython Demo - USB/Serial echo
-
+"""CircuitPython Essentials UART Serial example"""
 import board
 import busio
 import digitalio
 
+# For most CircuitPython boards:
 led = digitalio.DigitalInOut(board.D13)
+# For QT Py M0:
+# led = digitalio.DigitalInOut(board.SCK)
 led.direction = digitalio.Direction.OUTPUT
 
 uart = busio.UART(board.TX, board.RX, baudrate=9600)
diff --git a/CircuitPython_Essentials/I2C_Test_Script.py b/CircuitPython_Essentials/I2C_Test_Script.py
index 0105c61fd..8ecb8a548 100644
--- a/CircuitPython_Essentials/I2C_Test_Script.py
+++ b/CircuitPython_Essentials/I2C_Test_Script.py
@@ -1,7 +1,9 @@
+"""CircuitPython Essentials I2C possible pin-pair identifying script"""
 import board
 import busio
 from microcontroller import Pin
 
+
 def is_hardware_I2C(scl, sda):
     try:
         p = busio.I2C(scl, sda)
@@ -29,8 +31,5 @@ for scl_pin in get_unique_pins():
     for sda_pin in get_unique_pins():
         if scl_pin is sda_pin:
             continue
-        else:
-            if is_hardware_I2C(scl_pin, sda_pin):
-                print("SCL pin:", scl_pin, "\t SDA pin:", sda_pin)
-            else:
-                pass
+        if is_hardware_I2C(scl_pin, sda_pin):
+            print("SCL pin:", scl_pin, "\t SDA pin:", sda_pin)
diff --git a/CircuitPython_Essentials/PWM_Test_Script.py b/CircuitPython_Essentials/PWM_Test_Script.py
index 144abc08f..67810cdbb 100644
--- a/CircuitPython_Essentials/PWM_Test_Script.py
+++ b/CircuitPython_Essentials/PWM_Test_Script.py
@@ -1,3 +1,4 @@
+"""CircuitPython Essentials PWM pin identifying script"""
 import board
 import pulseio
 
diff --git a/CircuitPython_Essentials/SPI_Test_Script.py b/CircuitPython_Essentials/SPI_Test_Script.py
index 8680629a7..8096a2a81 100644
--- a/CircuitPython_Essentials/SPI_Test_Script.py
+++ b/CircuitPython_Essentials/SPI_Test_Script.py
@@ -1,3 +1,4 @@
+"""CircuitPython Essentials Hardware SPI pin verification script"""
 import board
 import busio
 
diff --git a/CircuitPython_Essentials/UART_Test_Script.py b/CircuitPython_Essentials/UART_Test_Script.py
index 7809497af..d132f198f 100644
--- a/CircuitPython_Essentials/UART_Test_Script.py
+++ b/CircuitPython_Essentials/UART_Test_Script.py
@@ -1,3 +1,4 @@
+"""CircuitPython Essentials UART possible pin-pair identifying script"""
 import board
 import busio
 from microcontroller import Pin
@@ -28,8 +29,5 @@ for tx_pin in get_unique_pins():
     for rx_pin in get_unique_pins():
         if rx_pin is tx_pin:
             continue
-        else:
-            if is_hardware_uart(tx_pin, rx_pin):
-                print("RX pin:", rx_pin, "\t TX pin:", tx_pin)
-            else:
-                pass
+        if is_hardware_uart(tx_pin, rx_pin):
+            print("RX pin:", rx_pin, "\t TX pin:", tx_pin)