Adding ability to skip device probing upon object init. Some hardware devices do not respond to these probes, or could be in reset when software object is created

Author: osterwood

adafruit_bus_device/i2c_device.py

@@ -57,25 +57,26 @@ class I2CDevice:
                 device.write(bytes_read)
     """
 
-    def __init__(self, i2c, device_address):
+    def __init__(self, i2c, device_address, probe=True):
         """
         Try to read a byte from an address,
         if you get an OSError it means the device is not there
         """
-        while not i2c.try_lock():
-            pass
-        try:
-            i2c.writeto(device_address, b'')
-        except OSError:
-            # some OS's dont like writing an empty bytesting...
-            # Retry by reading a byte
+        if probe:
+            while not i2c.try_lock():
+                pass
             try:
-                result = bytearray(1)
-                i2c.readfrom_into(device_address, result)
+                i2c.writeto(device_address, b'')
             except OSError:
-                raise ValueError("No I2C device at address: %x" % device_address)
-        finally:
-            i2c.unlock()
+                # some OS's dont like writing an empty bytesting...
+                # Retry by reading a byte
+                try:
+                    result = bytearray(1)
+                    i2c.readfrom_into(device_address, result)
+                except OSError:
+                    raise ValueError("No I2C device at address: %x" % device_address)
+            finally:
+                i2c.unlock()
 
         self.i2c = i2c
         self.device_address = device_address