Tag Archives: Five Volts

One Atmel ATtiny13A drives seven-segment LED displays

As the folks at Hack A Day recently noted, there really is nothing like the classic (and comforting) red glow of a red seven segment display.

And that is probably why a Maker by the name of “Five Volts” wanted to get his hands on a few ancient segmented displays. Unfortunately, controlling even one took up way too many microcontroller pins.┬áThe solution? Use a shift register.

“The principle is to control the display with four wires: vcc, ground, shift in clock [and] data in. To get a simple module, I developed a tiny PCB to plug in the LED display and at the back of it the shift register with current limitation resistors,” Five Volts wrote in a blog post.

“The challenge is to fit all these components on such small area, and to get these modules stackable. Then, it allows building a one to N seven segments display.”

Essentially, Five Volts uses a single ATtiny13 to control a total of six 7-segment displays.

“Each display is mounted on a hand-etched board, with a shift register and a handful of resistors soldered to the back,” Hack A Day’s Brian Benchoff explained.

“By having the microcontroller shift bits down the line, [Volts] created an extremely easy to interface 6-digit segment display – and the entire device can [even] be expanded.”

Interested in learning more? Both the board files and schematics are available here.