Using 4-digit 7-segment displays

A 7-segment display can be used for multiple purposes. One of them is to display times, which is exactly what we want to do in our final project. But how can we control them?

The 4-digit display has 12 pins: one pin for each digit (from 0 to 9), one pin for each segment, and a pin for the dot. So, to display anything, we have to send a high signal to the digit we want to set and then just set all pins to high, which we need to represent the character we want to display.

For instance, if we want to display the character of "1" in the fourth digit, we would set pin 4 and pins B and C to high.

To get a better understanding of this, take a look at the following diagram:

Figure 5.10 – A 7-segment display pinout

From the preceding diagram, you can see that pins 1 to 4 are being used to select the digit.

The 7-segment A-G pins are being used to control the segments and the dot pin is being used to set the...