LightEffect

Library to create light animations

This library allows you to easily create light animations from an Arduino board or an ATtiny microcontroller (traffic lights, chaser, shopkeeper sign, etc.)

The LEDs are connected to the digital outputs of the Arduino board or the microcontroller with a resistor limiting the current in the LED. The resistor value depends on the color of the LED and must take into account the current limitation of the digital output and the possibilities of the card.

The LEDs can be connected to the digital outputs by their anode or else by their cathode, but all LEDs must be connected in the same way. In addition, the digital outputs used must follow each other in ascending order of their numbering.

Caution: do not confuse digital output number and microcontroller's pin number (see the card or microcontroller documentation).

The library uses delay() function, which does not allow to use it in a program doing something other than managing light effects.

How to use the library

Include the library at the beginning of the program with #include <LightEffect.h>

Instantiate one or more group of LED by giving a name to the object and specifying the position of the first LED, the number of LEDs and the logic level to light them.

LightEffect mySign (4, 6, LOW);

The 6 LEDs are connected by their cathode since a LOW level lights them, the first LED is on digital output 4.

If several groups of LED are created, the sequences are played one after the others and must be cleverly chosen to give the impression of independence of each light effect (see the example given Electric_sign).

How to call the sequences

The sequences are called with the following syntax : objectName.function (); objectName is the name given to the object and function() one of the functions of the library (see below) with or without arguments. Example:

mySign.onRight();

Functions

onAll()

Turns on all the LEDs at once

offAll()

Turns off all the LEDs at once

onLeft()

Turns on the LEDs from right to left of the sign

offLeft()

Turns off the LEDs from right to left of the sign

onRight()

Turns on the LEDs from left to right of the sign

offRight()

Turns off the LEDs from left to right of the sign

blinkAll(N)

Flashes all LEDs at once N times (N is an integer)

movingFlashLeft()

Moves a flash from right to left of the sign

movingFlashRight()

Moves a flash from left to right of the sign

roundTrip()

Light effect (two dimly illuminated LEDs surrounding a bright LED) going back and forth (recommended number of LEDs at least equal to six)

shiftStopLeft()

Flashes move from right to left and accumulate at left of the sign

shiftStopRight()

Flashes move from left to right and accumulate at right of the sign

randomLightOn()

Lights up the LEDs randomly (analog input A5 is used for seed therefore do not use it as a digital output)

randomLightOff()

Turns off the LEDs randomly (analog input A5 is used for seed therefore do not use it as a digital output)

trafficLight()

Simulates two traffic lights at a road junction - The number of LEDs is necessarily 6 and this animation is used alone because of the duration of sequences

alternatingTrafficLight()

Simulates two alternating traffic lights - The number of LEDs is necessarily 6 and this simulation is used alone because of the duration of sequences.

Examples

The library is supplied with 6 examples of use.

Demo_LightEffect

This example will show you the possibilities of the library.

Traffic_Light

This example simulates two traffic lights of a crossing.

Alternating_Traffic_Light

This example simulates two traffic lights of a working zone.

Electric_sign

This example manages two groups of LED, the first one for a HOTEL sign and the second one for a PARK sign.

Work_lights

This example reproduces moving flashing lights to prevent dangerous areas as work or merging lanes.