added examples folder and .py file

Author: mrmcwethy

examples/demo.py

@@ -0,0 +1,44 @@
+# Simple demo of reading and writing the time for the PCF8523 real-time clock.
+# Change the if False to if True below to set the time, otherwise it will just
+# print the current date and time every second.  Notice also comments to adjust
+# for working with hardware vs. software I2C.
+
+import time
+import board
+# For hardware I2C (M0 boards) use this line:
+import busio as io
+# Or for software I2C (ESP8266) use this line instead:
+#import bitbangio as io
+
+import adafruit_pcf8523
+
+# Change to the appropriate I2C clock & data pins here!
+i2c_bus = io.I2C(board.SCL, board.SDA)
+
+# Create the RTC instance:
+rtc = adafruit_pcf8523.PCF8523(i2c_bus)
+
+# Lookup table for names of days (nicer printing).
+days = ("Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday")
+
+
+#pylint: disable-msg=bad-whitespace
+#pylint: disable-msg=using-constant-test
+if False:   # change to True if you want to set the time!
+    #                     year, mon, date, hour, min, sec, wday, yday, isdst
+    t = time.struct_time((2017,  10,   29,   10,  31,  0,    0,   -1,    -1))
+    # you must set year, mon, date, hour, min, sec and weekday
+    # yearday is not supported, isdst can be set but we don't do anything with it at this time
+    print("Setting time to:", t)     # uncomment for debugging
+    rtc.datetime = t
+    print()
+#pylint: enable-msg=using-constant-test
+#pylint: enable-msg=bad-whitespace
+
+# Main loop:
+while True:
+    t = rtc.datetime
+    #print(t)     # uncomment for debugging
+    print("The date is {} {}/{}/{}".format(days[int(t.tm_wday)], t.tm_mday, t.tm_mon, t.tm_year))
+    print("The time is {}:{:02}:{:02}".format(t.tm_hour, t.tm_min, t.tm_sec))
+    time.sleep(1) # wait a second