for loop

Hi Gordon,

This for loop throws an error:

for(i=0,j=7;i<10;i++,j++) { console.log('a'); }
ERROR: Got ',' expected ')' at line 1 col 22
for(i=0,j=7;i<10;i++,j++) { console.log('a'); }

                  ^

Is working on jconsole.com.

http://jsconsole.com/?for(i%3D0%2Cj%3D7%3Bi%3C10%3Bi%2B%2B%2Cj%2B%2B)%20%7B%20console.log(%27a%27)%3B%20%7D

Greetings

Sacha

Hmm - thanks. It should be an easy fix.

Ok - fixed for 1v61 :)

Thank you.

If a js code breaks from a for loop as follows, the loop index i should not be changed!

for(var i=0; i<10; i++) if(i==3)break; console.log(i)

Thanks for letting me know. I've just fixed this, so it'll be in the 1v71 release of Espruino.

do you know how to use this for loop similar to way like Arduino ?
eg.

for(int i=0 ; i<10 ; i++){
    digitalWrite(13, HIGH);
    delay(500);
    digitalWrite(13, LOW);
    delay(500);
}

I was trying to use tutorial from buttons example, and change it a bit, like when I press the button LED1 will blink let say twice or triple times, in arduino modification it is easy, how to do it in espruino?

Delay is not a good way to manage time dependant tasks as it uses all the resources for itself
You can do it this way:

var maxTime = 500;
var maxStep = 10;
var count = 0;
var timer;
var state = false;
var blinkActive = false;

function blink(){
  state = !state;
  digitalWrite(LED1,state);
  if (!state) count--;
  if (count===0){
    clearInterval(timer);
    blinkActive = false;
  }
}

function launchBlink(){
  if(blinkActive === false){
    count = maxStep;
    timer = setInterval(blink,maxTime);
    blinkActive = true;
  }
}

function onInit(){
  clearInterval();
  LED1.write(0);
  setWatch(launchBlink,BTN,{repeat: true, edge: 'rising', debounce: 100});
}

onInit();

delay() is a scourge upon Arduino, and a plague that we are largely free from over here in Espruino-land. delay() is horribly overused on Arduino, and it's only simpler for very basic cases - as soon as you start making things more complicated, you end up in a mess.

We have modern, sensible tools for non-blocking delays - setInterval(), setTimeout(), and setWatch() (for reacting to a pin change).

All of those tasks on Arduino would either block, or require a "blinkWithoutDelay" type approach

unsigned long lastBlink=0;
unsigned long turnOnLedAt=30000;
byte led1st=0;
byte led2st=0;
[#define](https://forum.espruino.com/search/?q=%23define) ledpin 13 
[#define](https://forum.espruino.com/search/?q=%23define) ledpin2 14 //note that there's no led connected here on normal arduino board

void loop() {
if (millis()+500 > lastBlink) {
led1st=!led1st;
digitalWrite(ledpin,led1st);
}
if (millis>turnOnLedAt && led2st==0) {
led2st=1;
digitalWrite(ledpin2,led2st);
}
}

vs Espruino:

ledpin1 = LED1;
ledpin2 = LED2;
var ledst=0;
function onInit () {
setTimeout("digitalWrite(ledpin2)",30000); 
setInterval("ledst=!ledst;digitalWrite(ledpin1,ledst);",500);
}

or

var ledst=0;
ledpin1 = LED1;
ledpin2 = LED2;
function onInit () {
setTimeout(function() {digitalWrite(ledpin2);},30000); 
setInterval(function() {ledst=!ledst;digitalWrite(ledpin1,ledst);},500);
}

it's working, now I have equivalent to for loop operations ;), thank you fdufnews
DrAzzy, your code generate some error

Thanks!

note that I have made a small correction to the code in order to prevent double launch of the blink sequence if it is already active.

cool, I had some counting problem when disconnected and connected board again, everything was working till I didn't use "save()" command and turned board off and back on, or disconnected and connected again, will check how it is going on now ;)

fdufnews - everything is workin now, even after power of and on again the board,
very helpful ;)

I fixed the code so it runs out of the box now - I had just omitted the definitions for the ledpin1/ledpin2 variables because I was illustrating how to write the code (just like how in the Arduino example, I didn't include definitions for the LED pins).

I also missed the second argument to digitalWrite() in one case.

Note that sometimes when copy/pasting code from these forums, it inserts non-printing junk characters. These get red-marked in the IDE, remove them where they appear.

DrAzzy, thank you, your code is also working now ;)