Simple Kotlin application to communicate with a PLC via Modbus

MainActivity.kt

/* @author: Juan Escobar (juan.escobar@dreamlab.net) */
package net.dreamlab.modbuscoils

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.os.StrictMode
import android.util.Log
import android.view.View
import io.ktor.network.selector.*
import io.ktor.network.sockets.*
import io.ktor.utils.io.*
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.runBlocking
import java.net.InetSocketAddress

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        StrictMode.setThreadPolicy(
            StrictMode.ThreadPolicy.Builder().permitAll().build())
    }

    /* https://stackoverflow.com/a/51404278/2067290 */
    private fun byteArrayOfInts(vararg ints: Int) = ByteArray(ints.size) { pos -> ints[pos].toByte() }

    /* Called when the user taps the ON button */
    fun turnOnLight(view: View) {
        runBlocking {
            val socket = aSocket(ActorSelectorManager(Dispatchers.IO)).tcp().connect(InetSocketAddress("plc_address", 502))
            val output = socket.openWriteChannel(autoFlush = true)

            val packet = byteArrayOfInts(0x00,0x01,0x00,0x00,0x00,0x06,0xff,0x05,0x00,0x00,0xff,0x00)
            output.writeFully(packet)
            socket.close()
        }
    }

    /* Called when the user taps the OFF button */
    fun turnOffLight(view: View) {
        runBlocking {
            val socket = aSocket(ActorSelectorManager(Dispatchers.IO)).tcp().connect(InetSocketAddress("ip_address", 502))
            val output = socket.openWriteChannel(autoFlush = true)

            val packet = byteArrayOfInts(0x00,0x01,0x00,0x00,0x00,0x06,0xff,0x05,0x00,0x00,0x00,0x00)
            output.writeFully(packet)
            socket.close()
        }
    }
}