Arduino Library for a 4-bit LED Digital Tube Module

This is a simple Arduino library for presenting a decimal number on a 4-bit LED Digital Tube Module that uses two 74HC595 shift registers. It's an unknown brand but can be bought on various sites on the net.

Usage

Put the contents of this repository in a folder named LEDDisplay74HC595 in the Arduino IDE's libraries folder. See the example file by opening it in the Arduino IDE: Open -> libraries -> LEDDisplay74HC595 -> LEDDisplay74HC595Example.

The display uses three digital out pins on your Arduino.

The refresh(number, decimalPlaces) method rounds to specified decimals places, e.g. refresh(1.234, 1) displays as 1.2.

Example

#include <LEDDisplay74HC595.h>

const int sclkPin = 4;
const int rclkPin = 5;
const int dioPin = 6;

LEDDisplay74HC595 ledDisplay(sclkPin, rclkPin, dioPin);

void setup() {
}

void loop() {
  ledDisplay.refresh(-1.267, 1);

  // Note that delaying will cause the display to flicker,
  // it seems like it can only drive one digit at a time
  // so to display all digits you must continuously loop
  // over the LEDDisplay74HC595::refresh(...) method.
}

No state

The display does not have a state for all digits; this means that you have to refresh the number value continuously in your sketch.

A tip is to use timer interrupts to drive the display to avoid flicker when you need to process other stuff as well.

Example

#include <TimerOne.h>
//...
void setup() {
  //...
  Timer1.initialize(5000);
  Timer1.attachInterrupt(refreshDisplay);
}
void refreshDisplay() {
  ledDisplay.refresh(myValue, 1);
}

License

MIT License. See LICENCE.txt.