Controlling Eight 7-Segment LED Displays
In this project, you'll learn how to connect and control eight 7-segment LED displays using the MAX7219 driver chip.
In the 7-segment LED display tutorial, you learned how to control one 7-segment LED display. In order to control more 7-segment LED displays you will need to use a dedicated LED driver chip such as the MAX7219. One MAX7219 driver chip allows you to easily control one to eight 7-segment LED displays. Furthermore, you can daisy chain eight MAX7219 chips together, each one controlling eight 7-segment displays, giving you a total of 64 7-segment LED displays!
Parts needed:
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1 | Making the connections
If your LED display is already connected to the MAX7219 chip, then skip this step and go to step 2. Otherwise, you need to make the following connections between the MAX7219 chip and your 7-segment LED display. The pinouts for the MAX7219 chip and 4-digit 7-segment LED display are shown on the right. Use the pin connections under either the Three 7-segment or Four 7-segment column depending on whether you have a 3-digit or 4-digit display.
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In addition, you need to make the following two connections on the MAX7219 chip:
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2 |
The MAX7219 chip requires five connections to the Arduino: DIN, CS, CLK, V+ and GND.
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3 | Download and save the LedControl library. Do not open it. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
4 | Install the LedControl library by selecting Sketch from the Arduino IDE menu
Click click the Open button (Refer to this document for more information on how to install a library if you run into problems.) | |||||||||||||||||||||||||||||||||||||||||||||||||||||
5 | Create a new program by selecting File from the menu
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6 | Upload and run the program.
Refer to the LedControl library reference documentation for details on how to use the functions in this library. | |||||||||||||||||||||||||||||||||||||||||||||||||||||