In a multiplexing configuration, the segments of the display are divided into groups, and each group is driven one at a time in a rapid sequence. The microcontroller cycles through each group and activates the corresponding segments for that group. This process happens so quickly that the human eye perceives all the segments as being continuously lit.

To multiplex a 7 segment LED display, we typically use a combination of common cathode or common anode configuration and a scanning technique. In a common cathode configuration, all the cathodes of the LED segments are connected together and connected to a microcontroller pin. In a common anode configuration, all the anodes of the LED segments are connected together and connected to a microcontroller pin.

To drive the segments, the microcontroller sequentially selects one group at a time by activating the corresponding common cathode or anode pin. For example, if we have four groups, the microcontroller will activate one group for a short period, turn it off, and then move on to the next group. This process is repeated continuously, giving the illusion that all the segments are continuously lit.

Multiplexing allows us to control multiple segments using fewer microcontroller pins, which is especially useful when dealing with limited pin availability. However, it is important to consider the refresh rate and duty cycle when using multiplexing. If the refresh rate is too low or the duty cycle is too high, the display may appear flickering or dim. Careful consideration of these factors is necessary to ensure a clear and bright display.

In conclusion, a 7 segment LED display can be effectively used in multiplexing applications to control multiple segments with fewer microcontroller pins. This technique offers a cost-effective and efficient solution for displaying numeric or alphanumeric information.