Required Hardware
This is a tutorial on multiplexing four seven-segment (Common Cathode LED displays from an Arduino using a single 4511 IC and a handful of transistors.
Wiring Instructions
To wire your 7-Segment 4-Digit Display (Common Cathode) to your 4511 and Arduino, connect the following pins:
- 7-Segment Pin1 –> 4511 Pin 9 via Resistor 390ohm
- 7-Segment Pin2 –> 4511 Pin 10 via Resistor 390ohm
- 7-Segment Pin3 –>
- 7-Segment Pin4 –> 4511 Pin 11 via Resistor 390ohm
- 7-Segment Pin5 –> 4511 Pin 14 via Resistor 390ohm
- 7-Segment Pin6 –> Transistor 4 NPN Pin 3 (Emitter)
- 7-Segment Pin7 –> 4511 Pin 12 via Resistor 390ohm
- 7-Segment Pin8 –> Transistor 3 NPN Pin 3 (Emitter)
- 7-Segment Pin9 –> Transistor 2 NPN Pin 3 (Emitter)
- 7-Segment Pin10 –> 4511 Pin 15 via Resistor 390ohm
- 7-Segment Pin11 –> 4511 Pin 13 via Resistor 390ohm
- 7-Segment Pin12 –> Transistor 1 NPN Pin 3 (Emitter)
- 4511 Pin 1 –> Arduino Pin 8
- 4511 Pin 2 –> Arduino Pin 7
- 4511 Pin 3 –> +5V
- 4511 Pin 4 –> +5v via Resistor 150Kohm
- 4511 Pin 5 –> GND
- 4511 Pin 6 –> Arduino Pin 6
- 4511 Pin 7 –> Arduino Pin 5
- 4511 Pin 8 –> GND
- 4511 Pins 9-15 to 7 Segments
- 4511 Pin 16 –> +5V
- Transistor 1 Pin 2 –> Arduino Pin 1 via Resistor 1Kohm
- Transistor 2 Pin 2 –> Arduino Pin 2 via Resistor 1Kohm
- Transistor 3 Pin 2 –> Arduino Pin 3 via Resistor 1Kohm
- Transistor 4 Pin 2 –> Arduino Pin 4 via Resistor 1Kohm
- Don’t forget to connect Pins 1 of the transistors to GND
Recommended Software
- none
There are PNP transistors shown on the schematic, not NPN and 3 7seg. LED display, not 4.
It is sold as either a Common Cathode or Common Anode Display.
I kind of remember to had linked two seven digits displays. using a single 7 bits output with two 4511 ‘s linked together, but can’t find nothing about that in Internet.
with 6 display??? is possible??
thanks