BlinkLED

This is a small lib for controlling a LED on specific output pin, implemented in non-blocking way.

It has been inspired by JLed and tries to keep close to that's API. Why am I not using JLED?

• need to specify PIN at setup(), not in constructor; to use BlinkLed inside a class
• didn't get it working yet :(
• don't need its analog functionality, resulting in smaller memory/flash footprint for this lib

Usage

Disclaimer: delay(ms) is only used to shorten the code for demonstration.

Initialize

BlinkLed led=BlinkLed();
void setup() {
    led.init(LED_BUILTIN); // LED connected to GND
}

Inverse LED

BlinkLed led=BlinkLed();
#define SOME_PIN_WITH_LED_ATTACHED_TO_VCC 13
void setup() {
    led.init(SOME_PIN_WITH_LED_ATTACHED_TO_VCC, true); // LED connected to VCC
}

Multiple LEDs

BlinkLed led1=BlinkLed();
BlinkLed led2=BlinkLed();
void setup() {
    led1.init(LED_BUILTIN);
    led2.init(12);
}

On/Off

• Switch on and off

void loop() {
    led.setBlink(-1,0).Update();		// LED on
    delay(5000);
    led.setBlink(0,0).Update();			// LED off
    delay(5000);
}

• Flashes (indicating activity)

void loop() {
    led.setBlink(-1,0).Update();		// LED on, starting a process
    delay(20);							// waiting for something?
    led.setBlink(0,0).Update();			// LED off at start of activity
    delay(5); 							// some activity, e.g. sending IR code
    led.setBlink(-1,0).Update();		// LED on after activity finished
    delay(15); 							// waiting for something more?
    led.setBlink(0,0).Update();			// done, LED finally off
    delay(5000);
}

Simple Blink

void setup() {
    //...
    led.setBlink(500,500);				// 1Hz
}
void loop() {
    led.Update();
}

Alternating Blink

• long and short lighting, alternating

int blinkIntervals[]={300, 300, 300, 100};
void setup() {
    //...
    led.setBlink(blinkIntervals);
}
void loop() {
    led.Update();
}

• Morse code (SOS aka ...---..., see https://en.wikipedia.org/wiki/Morse_code#Timing)

#define DIT 200		// milliseconds
#define DAH 3*DIT
#define GAP DIT
int blinkIntervals[]={
    DIT*6,		// word space
    DIT,
    GAP,
    DIT,
    GAP,
    DIT,			
    GAP*3,		// letter space
    DAH,
    GAP,
    DAH,
    GAP,
    DAH,
    GAP*3,		// letter space
    DIT,
    GAP,
    DIT,
    GAP,
    DIT
};
void setup() {
    //...
    led.setBlink(blinkIntervals);
}
void loop() {
    led.Update();
}

Hardware: connecting LED to PIN

• online calculator at https://www.elektronik-kompendium.de/sites/bau/1109111.htm

• dimensioning resistor for LED:

  VCC (chip)	color: red	color: yellow/green
  3.3V (ESP8266, ESP32)	150 Ohm	100 Ohm
  5V (ATmega*)	330 Ohm	270 Ohm

• detailed considerations (applied ohm's law and such):

  • R = U / I = (Vcc - Uled) / (I=10mA)
  • P = U * I = U * U / R
  • color=red
    • Vcc=5V: (5V-1,6..2,2V)/10mA = 340..280Ohm / power at short circuit of led with 330Ohm: 75mW/16mA
    • Vcc=3.3V: (3.3V-1,6..2,2V)/10mA = 170..110Ohm / power at short circuit of led with 150Ohm: 73mW/22mA
  • color=green/yellow
    • Vcc=5V: (5V-1,9..2,5)/10mA = 310..250Ohm -> power at short circuit of led with 270Ohm: 93mW/19mA
    • Vcc=3.3V: (3.3V-1,9..2,5V)/10mA = 140..80Ohm -> power at short circuit of led with 100Ohm: 73mW/33mA

Licensing & Contact

Licensed under LGPL v3.

Email: makerMcl (at) clauss.pro Please only email me if it is more appropriate than creating an Issue / PR. I will not respond to requests for adding support for particular boards, unless of course you are the creator of the board and would like to cooperate on the project. I will also ignore any emails asking me to tell you how to implement your ideas. However, if you have a private inquiry that you would only apply to you and you would prefer it to be via email, by all means.

Copyright

Copyright 2020 Matthias Clauß

TODOs

• implement unit tests
• improve argument checking / error handling for setBlinkPattern(word*, byte)