Update the millis() function to work with CircuitPython

time.time() was yielding integer number of seconds on CircuitPython.
This made subsequent calls to millis() yield the same result leading to
a divide by 0 issue when doing millis() - startTime()

Author: malcolm-sparkfun

examples/ex2_Presence_Sensing.py

@@ -51,15 +51,13 @@
 import time
 import sys
 
-# Define a function to get milliseconds. This depends on the platform
-if hasattr(time, "ticks_ms"):
-	# MicroPython: time.time() gives an integer, have to instead use ticks_ms()
+# Provide platform-dependent way to get current time in milliseconds
+if hasattr(time, "monotonic_ns"):
 	def millis():
-		return time.ticks_ms()
+		return time.monotonic_ns() // 1000000 # works in CircuitPython and Linux/Raspberry Pi
 else:
-	# Other platforms: time.time() gives a float
 	def millis():
-		return int(round(time.time() * 1000))
+		return time.time_ns() // 1000000 #only works in MicroPython
 
 def runExample():
 

examples/ex5_HeartRate.py

@@ -56,15 +56,13 @@
 import time
 import sys
 
-# Define a function to get milliseconds. This depends on the platform
-if hasattr(time, "ticks_ms"):
-	# MicroPython: time.time() gives an integer, have to instead use ticks_ms()
+# Provide platform-dependent way to get current time in milliseconds
+if hasattr(time, "monotonic_ns"):
 	def millis():
-		return time.ticks_ms()
+		return time.monotonic_ns() // 1000000 # works in CircuitPython and Linux/Raspberry Pi
 else:
-	# Other platforms: time.time() gives a float
 	def millis():
-		return int(round(time.time() * 1000))
+		return time.time_ns() // 1000000 #only works in MicroPython
 
 def runExample():
 

examples/ex6_FIFO_Readings.py

@@ -52,15 +52,13 @@
 import time
 import sys
 
-# Define a function to get milliseconds. This depends on the platform
-if hasattr(time, "ticks_ms"):
-	# MicroPython: time.time() gives an integer, have to instead use ticks_ms()
+# Provide platform-dependent way to get current time in milliseconds
+if hasattr(time, "monotonic_ns"):
 	def millis():
-		return time.ticks_ms()
+		return time.monotonic_ns() // 1000000 # works in CircuitPython and Linux/Raspberry Pi
 else:
-	# Other platforms: time.time() gives a float
 	def millis():
-		return int(round(time.time() * 1000))
+		return time.time_ns() // 1000000 #only works in MicroPython
 
 def runExample():