Understanding these three operations will make your life much easier.

Setting a Bit

The bitwise OR operator is used to set a bit. The following code snippet sets bit x.

extern uint8_t value;
value |= 1 << x;

Note: Using the |= assignment operator

value |= 1 << x;

is essentially the same as doing

value = value | (1 << x);

Example

Suppose we have the following value

...

0b00000100 | 0b00000001 = 0b00000101

Clearing a Bit

The bitwise AND operator can be used to clear a bit. The following code snippet clears bit x:

extern uint8_t value;
value &= ~(1 << x);

Note: Using the &= assignment operator

value &= ~(1 << x);

is essentially the same as doing

value = value & ~(1 << x);

Example

Suppose we have the following value 

...

0b00000111 & 0b11111101 = 0b00000101

Toggling a Bit

The XOR operator allows you to toggle a bit. The following code snippet toggles bit x.

extern uint8_t value;
value ^= 1 << x;

Note: Using the ^= assignment operator

value ^= 1 << x;

is essentially the same as doing

value = value ^ (1 << x);

Example

Suppose we have the following value

...

0b00000000 ^ 0b00000010 = 0b00000010

Checking a Bit

To check a bit, you can combine the right shift and AND operators. The following code snippet checks bit x.

extern uint8_t value;
bit = (value >> x) & 1;

Example

Suppose we have the following value

...

(0b00010111 >> 2) = 0b000000010b00000101

Then, the AND operator is applied

...