PROJECT 09 – 7-SEGMENT DISPLAY

OVERVIEW

You probably use 7-segment displays every day.

PINOUT

NOTES:

• The d1 pin doesn’t seem to work.
  
  
• CA = Common Anode (positive). So this chip uses a common positive pin for all LEDs.

• You can connect either CA pin to logical 1 and that will be the positive for each LED.

• Each LED (segment) has its own negative pin that has to be connect to GRND if you wish for that LED to be ON.

Notes:

• By grounding pin #3 (lamp test), it will turn on all the LEDs in the display (essentially showing 8). This is an easy way to test the display.
  
  
• The inputs represent a binary number with bits DCBA. So the value 8 is 1000 and 3 is 0011. Notice that D is the most significant bit and A is the least significant bit.

TASK

Create the circuit that uses the 7447 IC to drive a 7-segment display. You will have to show your teacher a few specific numbers. For example, here is the type of request that you will get: “Show me number 6”.