Add error check, update for Pi

Author: kattni

adafruit_us100.py

@@ -37,11 +37,10 @@
   https://github.com/adafruit/circuitpython/releases
 """
 
-# imports
-
 __version__ = "0.0.0-auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_US100.git"
 
+
 class US100:
     """Control a US-100 ultrasonic range sensor."""
 
@@ -63,6 +62,9 @@ def distance(self):
         """
         self._uart.write(bytes([0x55]))
         data = self._uart.read(2)  # 2 bytes return for distance
+        if not data:
+            raise RuntimeError("Sensor not found. Check your wiring!")
+
         if len(data) != 2:
             raise RuntimeError("Did not receive distance response")
         dist = (data[1] + (data[0] << 8)) / 10
@@ -73,6 +75,9 @@ def temperature(self):
         """Return the on-chip temperature, in Celsius"""
         self._uart.write(bytes([0x50]))
         data = self._uart.read(1)  # 1 byte return for temp
+        if not data:
+            raise RuntimeError("Sensor not found. Check your wiring!")
+
         if len(data) != 1:
             raise RuntimeError("Did not receive temperature response")
         temp = data[0] - 45

examples/us100_simpletest.py

@@ -1,14 +1,20 @@
 import time
-import board
-import busio
 import adafruit_us100
 
+# For use with a microcontroller:
+import board
+import busio
 uart = busio.UART(board.TX, board.RX, baudrate=9600)
-# Create a US-100 module instance.
+
+# For use with Raspberry Pi/Linux:
+# import serial
+# uart = serial.Serial("/dev/ttyS0", baudrate=9600, timeout=1)
+
 us100 = adafruit_us100.US100(uart)
 
 while True:
     print("-----")
     print("Temperature: ", us100.temperature)
+    time.sleep(0.5)
     print("Distance: ", us100.distance)
     time.sleep(0.5)