works with CPython too

Author: ladyada

adafruit_tfmini.py

@@ -71,12 +71,18 @@ def __init__(self, uart, *, timeout=1):
     @property
     def distance(self):
         """The most recent distance measurement in centimeters"""
+        try:
+            self._uart.reset_input_buffer()
+        except AttributeError:
+            # not implemented, we'll just keep going
+            pass
+
         # listen for new packet
         stamp = time.monotonic()
         while time.monotonic() - stamp < self.timeout:
             # look for the header start
             x = self._uart.read(1)
-            if x is None or x[0] != 0x59:
+            if not x or x[0] != 0x59:
                 continue
             # get remaining packet
             data = self._uart.read(8)
@@ -118,7 +124,7 @@ def _set_config(self, command):
         while (time.monotonic() - stamp) < self.timeout:
             # look for the header start
             x = self._uart.read(1)
-            if x is None or x[0] != 0x42:
+            if not x or x[0] != 0x42:
                 continue
             echo = self._uart.read(len(_STARTREPLY))
             #print("start ", [hex(i) for i in echo])

examples/tfmini_simpletest.py

@@ -1,17 +1,21 @@
 import time
-import board
+import board  # comment this out if using pyserial
+import busio  # comment this out if using pyserial
 import adafruit_tfmini
 
 # Use hardware uart
-import busio
 uart = busio.UART(board.TX, board.RX)
 
+# Or, you can use pyserial on any computer
+#import serial
+#uart = serial.Serial("/dev/ttyS2", timeout=1)
+
 # Simplest use, connect with the uart bus object
 tfmini = adafruit_tfmini.TFmini(uart)
 
-# You can put in 'long distance' mode
-#tfmini.mode = adafruit_tfmini.MODE_LONG
-#print("Now in mode", tfmini.mode)
+# You can put in 'short' or 'long' distance mode
+tfmini.mode = adafruit_tfmini.MODE_SHORT
+print("Now in mode", tfmini.mode)
 
 while True:
     print("Distance: %d cm (strength %d, mode %x)" %