ameer1234567890 / ShiftDisplay2

Arduino library for driving 7-segment displays using shift registers

https://ameer.io/ShiftDisplay2/

ShiftDisplay2

by Ameer Dawood

The original ShiftDisplay library was developed by Miguel Pynto. This is an enhanced fork by Ameer Dawood

Arduino library for driving 7-segment displays using shift registers

• Show numbers, text, and custom characters
• Use the whole display as one, or separate by individual sections
• Compatible with multiplexed drive and constant drive
• Compatible with common cathode and common anode
• Compatible with custom made and commercial display modules
• Maximum of 8 digits (for now)
• Concatenate multiple displays as one
• Only 3 pins used on Arduino

Hardware

• 1x (or more) 7-segment LED display
• 2x shift register (eg: 74HC595, TPIC6B595)
• 2x 0.1uF ceramic capacitor
• 8x (per display) 220 Ohm resistor

Wiring

1. Connect Arduino board to shift registers:

2. Connect shift registers to display(s):

Install

1. Launch the Arduino IDE
2. Open the Library Manager by going to menu: Sketch > Include Library > Manage Libraries
3. Search for ShiftDisplay2 library by typing shiftdisplay2 in Filter your search
4. Select ShiftDisplay2 by Ameer Dawood and click install

Example

#include <ShiftDisplay2.h>

ShiftDisplay2 display(COMMON_CATHODE, 3);

void setup() {
	for (int i = 3; i > 0; i--) {
		// store number and show it for 400ms
		display.set(i, ALIGN_CENTER);
		display.show(400);
		// add dot to stored number and show it for 400ms
		display.changeDot(1);
		display.show(400);
	}
	display.set("GO"); // store "GO"
}

void loop() {
	display.update(); // show stored "GO" while in loop
}

Reference

Constructors

• ShiftDisplay2()

  • ShiftDisplay2 display([latchPin, clockPin, dataPin, ]displayType, displaySize[, displayDrive])
  • ShiftDisplay2 display([latchPin, clockPin, dataPin, ]displayType, sectionSizes[, displayDrive])
  • ShiftDisplay2 display([latchPin, clockPin, dataPin, ]displayType, displaySize, swappedShiftRegisters[, indexes])
  • ShiftDisplay2 display([latchPin, clockPin, dataPin, ]displayType, sectionSizes, swappedShiftRegisters[, indexes])

  Create a ShiftDisplay2 object, initialize the library using the interface pins, display properties and configurations. A display can be set as a whole, or divided by sections. Sections can be a logical separation (for example hours and minutes on a 4 digit clock display), or a physical separation (for example timer and score on a scoreboard with multiple displays).

  latchPin, clockPin, dataPin (int): number of the Arduino digital pins connected to the latch, clock and data pins of the shift registers; if is not specified, the default pins are 6 for latch, 7 for clock, and 5 for data.

  displayType (DisplayType): type of the display, can be common anode or common cathode.

  displaySize (int): quantity of digits on the display.

  sectionSizes (int[]): quantity of digits for each section, defined by each value in array; end array with a 0 or lower value.

  displayDrive (DisplayDrive): drive algorithm of the display, can be multiplexed drive or static drive; if is not specified, the default is MULTIPLEXED_DRIVE.

  swappedShiftRegisters (bool): when set to true, changes shift registers order to first being digit index controller, and second being segment controller; if is specified, displayDrive is forced to MULTIPLEXED_DRIVE.

  indexes (int[]): custom digit index order, each array position contains the index of where the digit is output from the shift register; if is not specified, the default is { 0, 1, 2, 3, 4, 5, 6, 7 }.

Functions

• set()

  • display.set(number[, decimalPlaces][, leadingZeros][, alignment])
  • display.set(text[, alignment])
  • display.set(customs)
  • display.set(characters, dots)

  Encode and store a value for showing next on the display. The entire previous value is cleared.

  display (ShiftDisplay2): object where function is called.

  number (int | long | float | double): numeric value to set; if is too big to fit in the display, it is trimmed according to alignment.

  text (char | char[] | String): textual value to set; valid characters are 0-9 a-z A-Z -, other characters are converted to space; char array must be null-terminated; if is too big to fit in the display, it is trimmed according to alignment.

  customs (byte[]): custom characters to set, encoded in abcdefgp format, each byte is a character on the display, from left to right; array length must match display size.

  characters (char[]): characters to set, each char is a character on the display, from left to right; valid characters are 0-9 a-z A-Z -, other characters are converted to a space; array length must match display size.

  dots (bool[]): dot values to set, each bool is a dot on the display, from left to right; true to show the dot, false to hide the dot; array length must match display size.

  decimalPlaces (int): quantity of digits following the decimal point; the value is rounded according to this; if is set to 0, the decimal point will be removed; if is not specified, the default is 1 for real numbers and 0 for integer numbers.

  leadingZeros (bool): show or hide zeros on the left of value; if is not specified, the default is false.

  alignment (Alignment): alignment of the value on the display; if is not specified, the default is ALIGN_RIGHT for numbers and ALIGN_LEFT for text.

• scroll()

  • display.scroll(text[, speed])

  Scroll a string of text on the display. The entire previous value is cleared and this function automatically calls show().

  text (String | char[]): text to be scrolled on the display.

  speed (int): scrolling speed. This is essentially the number of miliseconds that each combination of letters are displayed. Thus, the speed increases as the value is decreased. ie; speed of 300 is faster than speed of 1000.

• changeDot()

  • display.changeDot(index[, dot])

  Modify the stored value by adding or hiding a dot.

  display (ShiftDisplay2): object where function is called.

  index (int): position on the display to change the dot, starting at 0 for the leftmost; if is out of bounds, function does not have any effect.

  dot (bool): true to show the dot, false to hide the dot; if is not specified, the default is true.

• changeCharacter()

  • display.changeCharacter(index, custom)

  Modify the stored value by replacing the character (and dot) with a custom character.

  display (ShiftDisplay2): object where function is called.

  index (int): position on the display to change the character, starting at 0 for the leftmost; if is out of bounds, function does not have any effect.

  custom (byte): custom character to set, encoded in abcdefgp format.

• setAt()

  • display.setAt(section, number[, decimalPlaces][, leadingZeros][, alignment])
  • display.setAt(section, text[, alignment])
  • display.setAt(section, customs)
  • display.setAt(section, characters, dots)

  Encode and store a value for showing next on the specified section. The section previous value is cleared.

  display (ShiftDisplay2): object where function is called.

  section (int): position of the section on the display to set the value, starting at 0 for the first; if is out of bounds, function does not have any effect.

  number (int | long | float | double): numeric value to set; if is too big to fit in the section, it is trimmed according to alignment.

  text (char | char[] | String): textual value to set; valid characters are 0-9 a-z A-Z -, other characters are converted to space; char array must be null-terminated; if is too big to fit in the section, it is trimmed according to alignment.

  customs (byte[]): custom characters to set, encoded in abcdefgp format, each byte is a character on the section, from left to right; array length must match section size.

  characters (char[]): characters to set, each char is a character on the section, from left to right; valid characters are 0-9 a-z A-Z -, other characters are converted to a space; array length must match section size.

  dots (bool[]): dot values to set, each bool is a dot on the section, from left to right; true to show the dot, false to hide the dot; array length must match section size.

  decimalPlaces (int): quantity of digits following the decimal point; the value is rounded according to this; if is set to 0, the decimal point will be removed; if is not specified, the default is 1 for real numbers and 0 for integer numbers.

  leadingZeros (bool): show or hide zeros on the left of value; if is not specified, the default is false.

  alignment (Alignment): alignment of the value on the section; if is not specified, the default is ALIGN_RIGHT for numbers and ALIGN_LEFT for text.

• changeDotAt()

  • display.changeDotAt(section, index[, dot])

  Modify the stored value by adding or hiding a dot in a section.

  display (ShiftDisplay2): object where function is called.

  section (int): position of the section on the display to change the dot, starting at 0 for the first; if is out of bounds, function does not have any effect.

  index (int): position on the section to change the dot, starting at 0 for the leftmost; if is out of bounds, function does not have any effect.

  dot (bool): true to show the dot, false to hide the dot; if is not specified, the default is true.

• changeCharacterAt()

  • display.changeCharacterAt(section, index, custom)

  Modify the stored value by replacing the character (and dot) with a custom character in a section.

  display (ShiftDisplay2): object where function is called.

  section (int): position of the section on the display to change the character, starting at 0 for the first; if is out of bounds, function does not have any effect.

  index (int): position on the section to change the character, starting at 0 for the leftmost; if is out of bounds, function does not have any effect.

  custom (byte): custom character to set, encoded in abcdefgp format.

• update()

  • display.update()

  Show on the display the stored value. For multiplexed drive, this must be called in a loop; for static drive, the value is shown until update()/clear()/show() is called.

  display (ShiftDisplay2): object where function is called.

• clear()

  • display.clear()

  Hide the display content, without erasing stored value.

  display (ShiftDisplay2): object where function is called.

• show()

  • display.show(time)

  Show on the display the stored value, for the given time, then clear. Blocking function.

  display (ShiftDisplay2): object where function is called.

  time (long): duration in milliseconds to show the value; exact time showing will be an under approximation.

Types

• DisplayType: COMMON_ANODE, COMMON_CATHODE
• DisplayDrive: MULTIPLEXED_DRIVE, STATIC_DRIVE
• Alignment: ALIGN_LEFT, ALIGN_RIGHT, ALIGN_CENTER

TODO

• Example for custom characters
• Example for static drive
• Schematics for static drive
• Remove display max size for static drive
• Implement deprecation warnings

Contacts

• https://github.com/ameer1234567890/ShiftDisplay2/
• https://twitter.com/ameer1234567890
• [e-mail]