In this circuit, we will build a BCD to 7 segment display decoder circuit using the 4511 chip. A BCD to 7 segment decoder circuit is a circuit that intakes a binary value and displays the equivalent decimal value on the 7 segment display. Using binary coded decimal (BCD), we can display any numerical digit on the 7 segment display from 0 to 9- using only 4 pins.
How the 4511 BCD to 7 segment display decoder works is it has 4 pins that intake a binary value. Each of these 4 pins can hold a 0 (LOW) or a 1 (HIGH). These data pins are referred to in the datasheet as D, B, C, and A. We can choose what digit we want to display by inputting the equivalent binary value into these data pins. For example, if we want to display 6 on the 7 segment display, we input the value 0110 into the DBCA data pins. The binary value 0110 is the equivalent of the decimal value of 6.
In this circuit, we will start the 4511 BCD to 7 segment display decoder with the most basic circuit. We will connect this chip by itself to pushbuttons. Using the pushbuttons, you can manually see how depending on which pushbuttons we press, how the output changes in response. So we can see which combinations of pushbuttons turned on displays which decimal values.