add switch example

Signed-off-by: Francois Berder <[email protected]>

Author: francois-berder

examples/switch_example.py

@@ -0,0 +1,37 @@
+#!/usr/bin/env python3
+"""This example shows how to add/remove callbacks to particular switch events.
+"""
+
+from letmecreate.core import switch
+from letmecreate.core.switch import SWITCH_1_PRESSED, SWITCH_2_PRESSED
+from letmecreate.core.switch import SWITCH_1_RELEASED, SWITCH_2_RELEASED
+from time import sleep
+
+
+def switch_pressed():
+    print("A switch has been pressed")
+
+
+def switch_released():
+    print("A switch has been released")
+
+
+# Initialise the switch and attach two callbacks
+switch.init()
+callback_id_pressed = switch.add_callback(SWITCH_1_PRESSED | SWITCH_2_PRESSED,
+                                          switch_pressed)
+callback_id_released = switch.add_callback(SWITCH_1_RELEASED|SWITCH_2_RELEASED,
+                                           switch_released)
+
+# Sleep main thread during 15 seconds.
+# The switch wrapper lives in another thread and will call switch_pressed
+# and switch_released
+print("Callbacks are now active for 15 seconds.")
+sleep(15)
+
+# Remove callbacks and release switch
+# In this case, it is not necessary to call switch.remove_callback()
+# since callbacks would get destroyed in switch.release().
+switch.remove_callback(callback_id_pressed)
+switch.remove_callback(callback_id_released)
+switch.release()