A work in progress

This is just so I have a kind of backup and reference.

activity_main.xml

The layout file.

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Battery Monitor"
        android:textSize="50sp"
        android:textStyle="bold"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.491"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.066" />

    <Button
        android:id="@+id/btn_Feedback"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Feedback"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.946"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.909" />

    <Button
        android:id="@+id/btn_Update"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Update"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.097"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.909" />

    <Button
        android:id="@+id/btn_Exit"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Exit"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.95"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="1.0" />

    <TextView
        android:id="@+id/tv_LastReading"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Last reading: "
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.090"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.226" />


    <TextView
        android:id="@+id/tv_LastReadingData"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="NA"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.169"
        app:layout_constraintStart_toEndOf="@+id/tv_LastReading"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.226" />

    <TextView
        android:id="@+id/tv_Temperature"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="32dp"
        android:text="Temperature: "
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.090"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/tv_LastReading" />


    <TextView
        android:id="@+id/tv_TemperatureData"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="32dp"
        android:text="NA"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.160"
        app:layout_constraintStart_toEndOf="@+id/tv_Temperature"
        app:layout_constraintTop_toBottomOf="@+id/tv_LastReadingData" />


    <TextView
        android:id="@+id/tv_BatteryOneData"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="32dp"
        android:layout_marginTop="32dp"
        android:text="NA"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.025"
        app:layout_constraintStart_toEndOf="@+id/tv_BatteryOne"
        app:layout_constraintTop_toBottomOf="@+id/tv_TemperatureData" />

    <TextView
        android:id="@+id/tv_BatteryTwoData"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="32dp"
        android:layout_marginTop="32dp"
        android:text="NA"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.025"
        app:layout_constraintStart_toEndOf="@+id/tv_BatteryTwo"
        app:layout_constraintTop_toBottomOf="@+id/tv_BatteryOneData" />

    <TextView
        android:id="@+id/tv_BatteryOne"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="32dp"
        android:text="Batterybank 1: "
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.090"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/tv_Temperature" />

    <TextView
        android:id="@+id/tv_BatteryTwo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="32dp"
        android:text="Batterybank 2: "
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.090"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/tv_BatteryOne" />


</androidx.constraintlayout.widget.ConstraintLayout>

build.gradle

Add this line:

implementation "org.jetbrains.anko:anko:0.10.4"

MainActivity.kt

The main program file:

package com.example.batterymonitorv01

import android.content.Intent
import android.content.Intent.ACTION_VIEW
import android.net.Uri
import android.os.Bundle
import android.widget.Button
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
import com.example.batterymonitor02.R
import org.jetbrains.anko.doAsync
import org.jetbrains.anko.toast
import org.jetbrains.anko.uiThread
import java.net.URL
import java.util.concurrent.Executors
import kotlin.system.exitProcess

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

        /* Declare the buttons */
        val btnExit: Button = findViewById(R.id.btn_Exit)
        val btnUpdate: Button = findViewById(R.id.btn_Update)
        val btnFeedBack: Button = findViewById(R.id.btn_Feedback)

        /* Declare button listeners */
        btnExit.setOnClickListener {
            finish()
            exitProcess(0)
        }

        btnUpdate.setOnClickListener {
            readData()
        }

        btnFeedBack.setOnClickListener {
            val openURL = Intent(ACTION_VIEW)
            openURL.data = Uri.parse("https:www.google.com/")
            startActivity(openURL)
        }
        /* Read the data when app starts */
        readData()

    }

    private fun readData() {

        val tvLastReadingData : TextView = findViewById(R.id.tv_LastReadingData)
        val tvTemperatureData : TextView = findViewById(R.id.tv_TemperatureData)

        val executor = Executors.newScheduledThreadPool(5)

        doAsync(executorService = executor) {
            val resultTemperature = URL("http://nerdegutta.org/kajsa/lastreadings/last_temperature.php").readText()
            val resultTime = URL("http://nerdegutta.org/kajsa/lastreadings/last_time.php").readText()
            uiThread {
                tvTemperatureData.text=resultTemperature
                tvTemperatureData.append("?C")
                tvLastReadingData.text=resultTime
            }
        }
        toast("Updated!")
    }

}

AndroidManifest.xml

The manifest file:

Add permission to use INTERNET Add permission to use ClearText

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.example.batterymonitor02">
    <uses-permission android:name="android.permission.INTERNET" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.BatteryMonitor02"
        android:usesCleartextTraffic="true">
        <activity
            android:name="com.example.batterymonitorv01.MainActivity"
            android:exported="true"
            tools:ignore="MissingClass">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>