Teknik Rehber

What Is a Dot Matrix LED Display? Showing Letters and Digits with 5×7 Displays

· Fark Tedarik
Dot matrix LED ekran nedir – Para Light A-3570SR 5×7 kırmızı dot matrix ekran, Fark Tedarik teknik rehber kapağı

A dot matrix LED display is a type of indicator made up of many LED dots arranged in rows and columns. Letters, digits and symbols are formed by lighting the right dots. Unlike 7-segment indicators, which can only show digits, dot matrix displays can show the whole alphabet, including Turkish characters, and special symbols. Elevator floor indicators, meters and control panels are the most familiar examples. In this article we have collected the basics for those looking into “how does a dot matrix display work” and “how to connect a 5×7 dot matrix”.

How Dot Matrix LED Displays Work

A 5×7 dot matrix display has 5 columns and 7 rows, 35 LEDs in total. Since bringing out each LED on a separate pin is not practical, the LEDs are connected in common to row and column lines: the anodes (or cathodes) of the LEDs in a row are joined, and the other ends of the LEDs in a column are joined. This way the 35 LEDs can be controlled with about 12 lines.

The multiplexing (scanning) method is used to create an image: at any moment only one row (or column) is enabled and the columns of the LEDs that should light in that row are driven. When the rows are scanned in turn hundreds of times per second, the human eye perceives this as a steady image. Scanning is usually done by a microcontroller, often with the help of shift registers and driver ICs.

Where Is It Used?

Dot matrix LED displays are preferred where short texts and symbols must be shown clearly:

  • Elevator and Floor Indicators: Information such as the floor number and direction arrows is shown so that it can be read from a distance.
  • Control Panels and Device Front Panels: Status codes, menu letters and short messages are displayed.
  • Energy Meters and Home Appliances: Measured values and operating modes are shown.
  • Scrolling Text Boards: Several modules are placed side by side to create scrolling text.
  • Alphanumeric Display Projects: In education and hobby projects, letters and animations are shown with a microcontroller.

Why Choose a Dot Matrix LED Display?

7-segment indicators are enough for digits but show letters only in a limited and hard-to-read way. LCD displays may be hard to read in dark or very bright environments and from wide angles. Dot matrix LED displays produce their own light, can be read clearly from a distance and from different angles, and work over a wide temperature range. These properties make them a reliable option for indicators in industrial and public areas.

The Solution: Para Light A-3570SR 5×7 Red Dot Matrix LED Display

Para Light A-3570SR 5×7 red dot matrix LED display with 3 mm dots

The Para Light A-3570SR is a 5×7 red dot matrix LED display from the 3570 series. It shows letters, digits and symbols with 35 LED dots. Each dot is 3 mm in diameter and has a dominant wavelength of 640 nm in Hyper Red. The typical luminous intensity per dot is 12 mcd at 10 mA, and the forward voltage at 20 mA is typically 1.9 V (max. 2.3 V). It is suitable for through-hole (DIP) mounting.

You can order this product from Fark Tedarik with a company invoice:

Buy the A-3570SR Now

You can browse other LED and display products in our LEDs and Displays category.

Additional Advantages and Usage Tips

When choosing a dot matrix display, the decisive dimension is not the total size of the display but the dot (pixel) diameter, the digits in the series code usually indicate it (3 mm dots in the 3570 series). The longer the reading distance, the larger the dot diameter should be. During multiplexing each row is lit only part of the time, so the average brightness drops. The current per row should be set without exceeding the pulse current limits in the datasheet, and a series resistor should be placed on each column line.

You can use shift register ICs to send the column data, and a 5 mm LED for a single indicator dot. Since the pin connection (row/column and common anode/cathode arrangement) varies by model, always check the manufacturer’s datasheet before wiring. For bulk purchases contact Fark Tedarik: https://farktedarik.com/iletisim/.

Frequently Asked Questions

What does 5×7 dot matrix mean?

It means that the display has 35 LED dots in total, arranged in 5 columns and 7 rows. This structure is enough to show standard Latin letters and digits legibly.

What is the difference between a dot matrix display and a 7-segment indicator?

A 7-segment indicator consists of seven bar segments and mainly shows digits. A dot matrix display is made of dots, so it can show all letters, digits, Turkish characters and symbols.

How is a dot matrix display connected to a microcontroller?

The row and column lines are connected to the microcontroller directly or through shift registers and driver ICs, and the rows are then scanned in turn by software. A current-limiting resistor should be added to each column line.

Why is the dot diameter important?

The dot diameter determines from how far the display can be read and its total size. 3 mm dots are suitable for panel and device indicators read from a short distance.