Bugfix Channel Scan

This Commit,
- Fixes Bug with Channel scan
- Adds tca9548a_channelscan.py example code for testing
- Updates examples.rst

Author: codenio

adafruit_tca9548a.py

@@ -77,7 +77,11 @@ def writeto_then_readfrom(self, address, buffer_out, buffer_in, **kwargs):
 
     def scan(self):
         """Perform an I2C Device Scan"""
-        return self.tca.i2c.scan()
+        self.try_lock()
+        try:
+            return self.tca.i2c.scan()
+        finally:
+            self.unlock()
 
 
 class TCA9548A:

docs/examples.rst

@@ -6,3 +6,12 @@ Ensure your device works with this simple test.
 .. literalinclude:: ../examples/tca9548a_simpletest.py
     :caption: examples/tca9548a_simpletest.py
     :linenos:
+
+Channel Scan
+-------------
+
+Ensure your device scans each channel of TCA9547A with Channel Scan.
+
+.. literalinclude:: ../examples/tca9548a_channelscan.py
+    :caption: examples/tca9548a_channelscan.py
+    :linenos:

examples/tca9548a_channelscan.py

@@ -0,0 +1,20 @@
+# SPDX-FileCopyrightText: 2021 codenio (Aananth K)
+# SPDX-License-Identifier: MIT
+
+# This example shows scanning of each TCA9548A channels.
+import board
+import busio
+import adafruit_tca9548a
+
+# Create I2C bus as normal
+i2c = busio.I2C(board.SCL, board.SDA)
+
+# Create the TCA9548A object and give it the I2C bus
+tca = adafruit_tca9548a.TCA9548A(i2c)
+
+# Scan the Main I2C Channel present in your board
+print(f"Scan of Main I2C Channel:{[hex(i) for i in i2c.scan()]}")
+
+# Scan Each TCA9548A channel
+for i in range(8):
+    print(f"Scan of TCA[i] Channel: {[hex(j) for j in tca[i].scan()]}")