Attempt to write then fall back to read for i2c detect

This approach was suggested by ladyada in
Adafruit_CircuitPython_BusDevice PR #22:
#22 (comment)

> ok tested with a plethora of sensors and the VEML6075 hates this
> so turns out you actually need something like....

    def __init__(self, i2c, device_address):
        """
        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
            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

Author: pdp7

adafruit_bus_device/i2c_device.py

@@ -56,6 +56,7 @@ class I2CDevice:
             with device:
                 device.write(bytes_read)
     """
+
     def __init__(self, i2c, device_address):
         """
         Try to read a byte from an address,
@@ -64,10 +65,15 @@ def __init__(self, i2c, device_address):
         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)
+            # 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()