AddAlarmActivity.kt

R.id.submit -> if (validInput()) {
    // TODO: save Alarm
    val alarm = TextAlarm(alarmName?.text.toString(), alarmTime)
    var alarmIntent = Intent(this, AlarmReceiver::class.java)
    val bundle = Bundle()
    bundle.putParcelable(DismissAlarmActivity.ALARM_EXTRA, alarm)
    alarmIntent.putExtras(bundle)
    val pendingIntent = PendingIntent.getBroadcast(this@AddTextAlarmActivity, 0, alarmIntent, PendingIntent.FLAG_UPDATE_CURRENT)
    val alarmManager = getSystemService(ALARM_SERVICE) as AlarmManager
    alarmManager.set(AlarmManager.RTC_WAKEUP, alarm.time?.asCalendar?.timeInMillis ?: 0, pendingIntent)
}

BroadcastReceiver.kt

package com.adammcneilly.personalalarmclock

import android.content.Context
import android.content.Intent
import android.media.RingtoneManager
import android.net.Uri
import android.support.v4.content.WakefulBroadcastReceiver
import android.util.Log


/**
 * Called when an alarm goes off.

 * Created by adam.mcneilly on 3/25/17.
 */
class AlarmReceiver : WakefulBroadcastReceiver() {
    override fun onReceive(context: Context, intent: Intent) {
        // Get alarm and send to new activity
        val alarm = intent.extras.getParcelable<Alarm>(DismissAlarmActivity.ALARM_EXTRA)

        // Only start an alarm if alarm is not null, otherwise we screw over the user
        if (alarm != null) {
            val intent = Intent(context, DismissAlarmActivity::class.java)
            intent.putExtra(DismissAlarmActivity.ALARM_EXTRA, alarm)
            context.startActivity(intent)

            //this will sound the alarm tone
            //this will sound the alarm once, if you wish to
            //raise alarm in loop continuously then use MediaPlayer and setLooping(true)
            var alarmUri: Uri? = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_ALARM)

            if (alarmUri == null) {
                alarmUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION)
            }

            val ringtone = RingtoneManager.getRingtone(context, alarmUri)
            ringtone.play()
        }
    }
}