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Notification with Javascript

nodejs

#1

Hi !

I’m fighting with what looks to be a really simple problem. At below code I need that <blynk.notify>
work inside <PIR1.watch> function, but ir works only outside, as you see in my comments.

Am I doing a big or small mistake? (or too many)?

Code works just ok, it reads a PIR sensor value and I would like to notify an alert just when a virtual button is ON (kind of alarm start/stop button).

Now I just need to know how deal with <blynk.notify>.

Any help appreciated. Thanks in advance.

var Blynk = require('blynk-library');
var AUTH = 'yabadaba';
var blynk = new Blynk.Blynk(AUTH, options = {
 connector : new Blynk.TcpClient()
});

var v5 = new blynk.VirtualPin(5);  // Alarm button

blynk.on('connect', function() {
  blynk.syncVirtual(5);
  notify();
});

v5.on('write', function(param5) {  // Watches for V5 Button
  console.log('V5:', param5[0]);  // prints value to CLI
});

var Gpio = require('/usr/lib/node_modules/onoff').Gpio
  pir1 = new Gpio(24, 'in', 'both');  // Pi BCM # 24 - sensor PIR1

function notify()
{
blynk.notify('Alert!'); ====> IT WORKS HERE
pir1.watch(function(err, value, param5,blynk) {
blynk.notify('AEEEHH');  ====> DOES NOT WORK HERE
if (err) throw err;
    if ((value == 1) & (param5 == 0)) {
        console.log('PIR:', value);
    }
    else if ((value == 1) & (param5 == 1)) {
        console.log('PIR:', value);
        blynk.notify('Alert!');  ====> DOES NOT WORK HERE
    }
      else {
        console.log('PIR:', value);
    }
});
}

#2

I don’t think the param value is carried outside of its assigned function. You would need to transfer it to a variable first.

This looks like you are triggering the function on rise and fall of a sensor trigger… this could cause rapid double triggers and notifications have a 5 second limit between such (Looks like that was recently updated from previous 15 seconds :+1: )


#3

Param and pir1 are working well, console shows PIR sensor states changing as we pass near it, as well changes on virtual button value.
I just don’t understand why “blynk.notify” does not work inside <pir1.watch>, just outside.

Output sample:

OnOff mode
Connecting to TCP: blynk-cloud.com 80
Connected
Authorized
V5: 0
V5: 1
PIR: 1
PIR: 0
V5: 0
PIR: 1
V5: 1
PIR: 0
PIR: 1
PIR: 0
V5: 0


#4

Do you have solid evidence of total compliance? Try printing the value of your param5 to the console at all expected locations.

Also, I think this should be like such… note the removal of unneeded brackets and addition of the needed 2nd ampersand.

if (value == 1 && param5 == 0) {

https://www.w3schools.com/js/js_comparisons.asp


#5

Maybe you should rethink the entire project. I notice the notify() function is triggered only one time, on blynk connect.


#6

Ok, I’m at work right now, will try to understand JS better to know what is happening, and will post results after reach them (I hope).
Thanks a lot, guys.


#7

Hey guys, think I’ve done it.

I’m suffering with Javascript but at least code is working right now, maybe it is not perfect but works.

When alarm button is off, no notifications sent, after turn it on I get max 3 notifications and it stop to
send them (to avoid message overload). If I turn alarm button off and on again and PIR sensor get new movements it will send more 3 notifications max.

Thanks a lot for your support, Gunner (Gicus too). Change the status for “solved” if you want.

In time: now I know that only one ampersand works with numbers but is discouraged, so I’m using 2 now. Learned a little bit of JS, thanks!

var Blynk = require('blynk-library');
var AUTH = 'yabadaba';
var blynk = new Blynk.Blynk(AUTH, options = {
 connector : new Blynk.TcpClient()
});

var v5 = new blynk.VirtualPin(5);  // Alarm button

notify();
function notify() {
blynk.notify('Alert!');
}

blynk.on('connect', function() {
  blynk.syncVirtual(5);
});

var Gpio = require('/usr/lib/node_modules/onoff').Gpio
  pir1 = new Gpio(24, 'in', 'both');  // Pi BCM # 24 - sensor PIR1

v5.on('write', function(param) {  // Watches for V5 Button
//  console.log('V5:', param[0]);  // prints value to CLI
counter = 0;
pir1.watch(function(err, value) {

if (err) throw err;
    if ((value == 1) && (param == 1)) {
        notify();
        counter++;
        if (counter == 3) {//notifies only 3 times (turn off/on alarm button to reactivate)
          param = 0;
        }
//        blynk.email('PIR Alert', 'Movement');//email optional
    }
});

});

#8
Comparing Different Types

Comparing data with different types could give you an unexpected results.

Comparing string with a number JavaScript converts both variables to a number and then do the comparison.
Case Value
3 < 13 true
3 < “13” true
3 < “Billy” false
3 > “Billy” false
3 == “Billy” false
“3” < “13” false
“3” > “13” true
“3” == “13” false

https://www.welookups.com/js/js_comparisons.html


#9

Thank you a lot, vowukur!
I’m not proficient on programming and totally new to JS, so I appreciate your attention and tips! I’ll pay attention on this from now on, now I see that JS has its own idiosyncrasies and its not obvious.
Kind regards.