Nsryjdtyk

I am trying to build a loop that my server will run, pinging an arduino which will return data when it receives a packet from my IP. I already have the mongoDB collection working for the data and am just stuck at this point where I would like my server to begin pinging the arduino every few seconds from start up.

Note: this is really my first crack at really understanding async JS and is likely just a noob mistake.

Code:

const dgram = require('dgram');

const message = Buffer.from('Some bytes');

const clientPing = dgram.createSocket('udp4');



const pinging = true;



function ping() {



  return new Promise ((resolve, reject) => {



    // This chunk

    clientPing.send("Hi Uno", 8888, 'xxx.xx.xx.xxx', (err) => {

      clientPing.close();

    });

    // When run on it's own successfully pings the arduino



    const error = false;



    if(error == true) {

      reject('Error');

    } else {

      resolve('Pinged');

    }



  });



}



//Working ping

ping().then().catch(err => console.log(err));

All of this above was meant to act as just a simple proof that the promise does work and successfully emits a udp packet to the target.

function loop() {

  while(pinging == true) {

    setTimeout(() => {

      ping().then().catch(err => console.log(err));

      console.log('Pinged');

    }, 3000);

  }

}

The rest of these are just different combinations of how I've tried to solve the problem here. As far as I can tell I don't have a memory leak as the loop runs just fine without increasing resource consumption.

function loop() {

  console.log("entered loop")

  while(pinging == true) {

    setTimeout(() => {

      clientPing.send("Hi Uno", 8888, 'xxx.xx.xx.xxx', (err) => {

        clientPing.close();

      });

      console.log('Pinged');

    }, 3000);

  }

}

This one was intended to run just the code for the ping without using the promise but still doesn't yield the desired result. The console.log is printed above but it doesn't seem to ever trigger the timeout.

loop();

This just runs one of the two loop() functions.

do {

  setTimeout(() => {

    ping().then().catch(err => console.log(err));

    console.log("pinged");

  }, 2000)

} while(pinging == true)

Lastly I thought I'd try do but also without success.

If all of these are pasted into a document sequentially it builds my file. Simply uncomment/comment out each section as needed.

Am I just missing something obvious or is there something fairly complex here that's stopping this from working?

Thanks!

Your ping function is written incorrectly. It is resolving promise just after sending ping not on callback of it. Please change it like this.

function ping() {

  return new Promise ((resolve, reject) => {



    // This chunk

    clientPing.send("Hi Uno", 8888, 'xxx.xx.xx.xxx', (err) => {

      const error = false;



      clientPing.close();



      if(error == true) {

        reject('Error');

      } else {

        resolve('Pinged');

      }



    });

  });



}

And for looping if you shouldn't do sync loop it won't wait until setTimeout finished or your function has finished executing.

For async looping you can loop it by async await
for example:

function wait () {

  return new Promise((resolve, reject)=> {

     setTimeout(() => {

       resolve()

     }, 3000)

  })

}



for (let i = 0; i<n; i++) {

   await ping();

   await wait();

}