https://devzone.nordicsemi.com/f/nordic-q-a/23116/what-does-mask-and-1-meanWhat does mask and 1&lt;&lt; mean in the following code: #define BSP_LED_0_MASK (1&lt;&lt;BSP_LED_0) #define BSP_LED_1_MASK (1&lt;&lt;BSP_LED_1) #define BSP_LED_2_MASK (1&lt;&lt;BSP_LED_2) #define BSP_LED_3_MASK (1&lt;&lt;BSP_LED_3)en-USTelligent Community 13Thu, 29 Jun 2017 08:03:04 GMThttps://devzone.nordicsemi.com/thread/90946?ContentTypeID=1Thu, 29 Jun 2017 08:03:04 GMT137ad170-7792-4731-bb38-c0d22fbe4515:bfe63469-579b-4619-ab8d-dca94907e2b0Stian R&#248;ed Hafskjold<p><a href="https://en.wikipedia.org/wiki/Bitwise_operations_in_C#Left_shift_.3C.3C">en.wikipedia.org/.../Bitwise_operations_in_C</a></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/90947?ContentTypeID=1Wed, 28 Jun 2017 14:01:48 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9be911bb-45df-43c2-9801-d04fbd5068ceTurbo J<p>If you don&#39;t know what <code>&lt;&lt;</code> is doing, you <em>really</em> need to read a book about the C programming language. This should also explain what a bitmask is.</p><div style="clear:both;"></div>