Add external interrupt updater example

pyboard/GPIO_interrupt_updater.py

@@ -0,0 +1,47 @@
+from pyb import UART
+from pyb import ExtInt
+from pyb import Pin
+from micropyGPS import MicropyGPS
+
+# Global Flag to Start GPS data Processing
+new_data = False
+
+
+# Callback Function
+def pps_callback(line):
+    print("Updated GPS Object...")
+    global new_data  # Use Global to trigger update
+    new_data = True
+
+print('GPS Interrupt Tester')
+
+# Instantiate the micropyGPS object
+my_gps = MicropyGPS()
+
+# Setup the connection to your GPS here
+# This example uses UART 3 with RX on pin Y10
+# Baudrate is 9600bps, with the standard 8 bits, 1 stop bit, no parity
+# Also made the buffer size very large (1000 chars) to accommodate all the characters that stack up
+# each second
+uart = UART(3, 9600, read_buf_len=1000)
+
+# Create an external interrupt on pin X8
+pps_pin = pyb.Pin.board.X8
+extint = pyb.ExtInt(pps_pin, pyb.ExtInt.IRQ_FALLING, pyb.Pin.PULL_UP, pps_callback)
+
+# Main Infinite Loop
+while 1:
+    # Do Other Stuff Here.......
+
+    # Update the GPS Object when flag is tripped
+    if new_data:
+        while uart.any():
+            my_gps.update(chr(uart.readchar()))  # Note the conversion to to chr, UART outputs ints normally
+        
+        print('UTC Timestamp:', my_gps.timestamp)
+        print('Date:', my_gps.date_string('long'))
+        print('Latitude:', my_gps.latitude_string())
+        print('Longitude:', my_gps.longitude_string())
+        print('Horizontal Dilution of Precision:', my_gps.hdop)
+        print()
+        new_data = False  # Clear the flag