Merge pull request #4 from adafruit/stemma_i2c

Added commented out board.STEMMA_I2C with explanation

Author: evaherrada

examples/pcf8574_blink8outputs.py

@@ -9,7 +9,8 @@
 
 print("PCF8574 8 output LED blink test")
 
-i2c = board.I2C()
+i2c = board.I2C()  # uses board.SCL and board.SDA
+# i2c = board.STEMMA_I2C()  # For using the built-in STEMMA QT connector on a microcontroller
 pcf = adafruit_pcf8574.PCF8574(i2c)
 
 

examples/pcf8574_buttonled.py

@@ -10,7 +10,8 @@
 
 print("PCF8574 digitalio LED + button test")
 
-i2c = board.I2C()
+i2c = board.I2C()  # uses board.SCL and board.SDA
+# i2c = board.STEMMA_I2C()  # For using the built-in STEMMA QT connector on a microcontroller
 pcf = adafruit_pcf8574.PCF8574(i2c)
 
 # get a 'digitalio' like pin from the pcf

examples/pcf8574_read8inputs.py

@@ -9,7 +9,8 @@
 
 print("PCF8574 8 input button test")
 
-i2c = board.I2C()
+i2c = board.I2C()  # uses board.SCL and board.SDA
+# i2c = board.STEMMA_I2C()  # For using the built-in STEMMA QT connector on a microcontroller
 pcf = adafruit_pcf8574.PCF8574(i2c)
 
 

examples/pcf8574_simpletest.py

@@ -9,7 +9,8 @@
 
 print("PCF8574 digitalio LED blink test")
 
-i2c = board.I2C()
+i2c = board.I2C()  # uses board.SCL and board.SDA
+# i2c = board.STEMMA_I2C()  # For using the built-in STEMMA QT connector on a microcontroller
 pcf = adafruit_pcf8574.PCF8574(i2c)
 
 # get a 'digitalio' like pin from the pcf