implements continuous mode context manager, plus an example for simple continuous

Author: Smankusors

adafruit_vl53l0x.py

@@ -588,16 +588,26 @@ def read_range(self):
         return range_mm
 
     @property
-    def continuous_mode(self):
-        """Is the sensor currently in continuous mode?"""
+    def is_continuous_mode(self):
+        """Is the sensor currently in continuous mode?
+        """
         return self._continuous_mode
 
-    @continuous_mode.setter
-    def continuous_mode(self, enabled):
-        if enabled:
-            self.start_continuous()
-        else:
-            self.stop_continuous()
+    def continuous_mode(self):
+        """Create a new context manager to manage the continuous mode
+        """
+        class continuous_manager:
+            def __init__(self, driver):
+                self.driver = driver
+
+            def __enter__(self):
+                self.driver.start_continuous()
+                return self.driver
+
+            def __exit__(self, exc_type, exc_value, tb):
+                self.driver.stop_continuous()
+
+        return continuous_manager(self)
 
     def start_continuous(self):
         """Perform a continuous reading of the range for an object in front of
@@ -641,6 +651,9 @@ def stop_continuous(self):
             self._write_u8(pair[0], pair[1])
         self._continuous_mode = False
 
+        # restore the sensor to single ranging mode
+        self.do_range_measurement()
+
     def set_address(self, new_address):
         """Set a new I2C address to the instantaited object. This is only called when using
         multiple VL53L0X sensors on the same I2C bus (SDA & SCL pins). See also the

examples/vl53l0x_continuous.py renamed to examples/vl53l0x_multiple_sensors_continuous.py

@@ -52,9 +52,7 @@
     vl53.insert(i, VL53L0X(i2c))  # also performs VL53L0X hardware check
 
     # start continous mode
-    vl53[i].continuous_mode = True
-    # or alternatively with this
-    # vl53[i].start_continous()
+    vl53[i].start_continous()
 
     # you will see the benefit of continous mode if you set the measurement timing
     # budget very high.
@@ -86,11 +84,11 @@ def detect_range(count=5):
 
 
 def stop_continuous():
-    """ this is not required, unless if you want to save some energy """
+    """ this is not required, if you use XSHUT to reset the sensor.
+    unless if you want to save some energy
+    """
     for sensor in vl53:
-        sensor.continuous_mode = False
-        # or alternatively with this
-        # sensor.stop_continuous()
+        sensor.stop_continuous()
 
 
 if __name__ == "__main__":

examples/vl53l0x_simplecontinuous.py

@@ -0,0 +1,36 @@
+# Simple demo of the VL53L0X distance sensor with continuous mode.
+# Will print the sensed range/distance as fast as possible.
+import time
+
+import board
+import busio
+
+import adafruit_vl53l0x
+
+# Initialize I2C bus and sensor.
+i2c = busio.I2C(board.SCL, board.SDA)
+vl53 = adafruit_vl53l0x.VL53L0X(i2c)
+
+# Optionally adjust the measurement timing budget to change speed and accuracy.
+# See the example here for more details:
+#   https://github.com/pololu/vl53l0x-arduino/blob/master/examples/Single/Single.ino
+# For example a higher speed but less accurate timing budget of 20ms:
+# vl53.measurement_timing_budget = 20000
+# Or a slower but more accurate timing budget of 200ms:
+vl53.measurement_timing_budget = 200000
+# The default timing budget is 33ms, a good compromise of speed and accuracy.
+
+# You will see the benefit of continous mode if you set the measurement timing
+# budget very high, while your program doing something else. When your program done
+# with something else, and the sensor already calculated the distance, the result
+# will return instantly, instead of waiting the sensor measuring first.
+
+# Main loop will read the range and print it every second.
+with vl53.continuous_mode():
+    while True:
+        # try to adjust the sleep time (simulating program doing something else)
+        # and see how fast the sensor returns the range
+        time.sleep(0.1)
+
+        curTime = time.time()
+        print("Range: {0}mm ({1:.2f}ms)".format(vl53.range, time.time() - curTime))