Do While Loop not triggered in cron job (Laravel)

The requirement is to set up a cron job that runs every 4 seconds. Since cron jobs can be executed only in minutes, I decided the trigger my job every minute and within the job, run it several time. Here's the code.

public function handle()
{

    $dt = Carbon::now();
    $counter = 60/4; //run the job every 4 seconds
    do {
        //logic goes here
        time_sleep_until($dt->addSeconds(4)->timestamp);
    } while ($counter-- > 0);
}

Cron job is scheduled as in crontab -e

*/1 * * * * /usr/bin/php /var/www/html/dashboard/artisan cronjob:pulldata

Job runs perfectly every 4 seconds when I execute it manually with the php artisan command. But, it executes only once a minute when it is triggered by the cronjob from crontab -e.

via Chebli Mohamed