diff --git a/esp32/README.md b/esp32/README.md
deleted file mode 100644
index d078cb1..0000000
--- a/esp32/README.md
+++ /dev/null
@@ -1 +0,0 @@
-# ESP32 related content
\ No newline at end of file
diff --git a/pio/.DS_Store b/pio/.DS_Store
new file mode 100644
index 0000000..33ab2d8
Binary files /dev/null and b/pio/.DS_Store differ
diff --git a/pio/.gitignore b/pio/.gitignore
new file mode 100644
index 0000000..89cc49c
--- /dev/null
+++ b/pio/.gitignore
@@ -0,0 +1,5 @@
+.pio
+.vscode/.browse.c_cpp.db*
+.vscode/c_cpp_properties.json
+.vscode/launch.json
+.vscode/ipch
diff --git a/pio/include/README b/pio/include/README
new file mode 100644
index 0000000..45496b1
--- /dev/null
+++ b/pio/include/README
@@ -0,0 +1,39 @@
+
+This directory is intended for project header files.
+
+A header file is a file containing C declarations and macro definitions
+to be shared between several project source files. You request the use of a
+header file in your project source file (C, C++, etc) located in `src` folder
+by including it, with the C preprocessing directive `#include'.
+
+```src/main.c
+
+#include "header.h"
+
+int main (void)
+{
+ ...
+}
+```
+
+Including a header file produces the same results as copying the header file
+into each source file that needs it. Such copying would be time-consuming
+and error-prone. With a header file, the related declarations appear
+in only one place. If they need to be changed, they can be changed in one
+place, and programs that include the header file will automatically use the
+new version when next recompiled. The header file eliminates the labor of
+finding and changing all the copies as well as the risk that a failure to
+find one copy will result in inconsistencies within a program.
+
+In C, the usual convention is to give header files names that end with `.h'.
+It is most portable to use only letters, digits, dashes, and underscores in
+header file names, and at most one dot.
+
+Read more about using header files in official GCC documentation:
+
+* Include Syntax
+* Include Operation
+* Once-Only Headers
+* Computed Includes
+
+https://gcc.gnu.org/onlinedocs/cpp/Header-Files.html
diff --git a/pio/lib/README b/pio/lib/README
new file mode 100644
index 0000000..8c9c29c
--- /dev/null
+++ b/pio/lib/README
@@ -0,0 +1,46 @@
+
+This directory is intended for project specific (private) libraries.
+PlatformIO will compile them to static libraries and link into executable file.
+
+The source code of each library should be placed in a an own separate directory
+("lib/your_library_name/[here are source files]").
+
+For example, see a structure of the following two libraries `Foo` and `Bar`:
+
+|--lib
+|  |
+|  |--Bar
+|  |  |--docs
+|  |  |--examples
+|  |  |--src
+|  |     |- Bar.c
+|  |     |- Bar.h
+|  |  |- library.json (optional, custom build options, etc) https://docs.platformio.org/page/librarymanager/config.html
+|  |
+|  |--Foo
+|  |  |- Foo.c
+|  |  |- Foo.h
+|  |
+|  |- README --> THIS FILE
+|
+|- platformio.ini
+|--src
+   |- main.c
+
+and a contents of `src/main.c`:
+```
+#include <Foo.h>
+#include <Bar.h>
+
+int main (void)
+{
+  ...
+}
+
+```
+
+PlatformIO Library Dependency Finder will find automatically dependent
+libraries scanning project source files.
+
+More information about PlatformIO Library Dependency Finder
+- https://docs.platformio.org/page/librarymanager/ldf.html
diff --git a/pio/platformio.ini b/pio/platformio.ini
new file mode 100644
index 0000000..168304a
--- /dev/null
+++ b/pio/platformio.ini
@@ -0,0 +1,23 @@
+; PlatformIO Project Configuration File
+;
+;   Build options: build flags, source filter
+;   Upload options: custom upload port, speed and extra flags
+;   Library options: dependencies, extra library storages
+;   Advanced options: extra scripting
+;
+; Please visit documentation for the other options and examples
+; https://docs.platformio.org/page/projectconf.html
+
+[env:fm-devkit]
+platform = espressif32
+board = fm-devkit
+framework = arduino
+lib_deps = 
+	miguelbalboa/MFRC522@^1.4.11
+	adafruit/Adafruit SSD1306@^2.5.9
+	adafruit/Adafruit GFX Library@^1.11.9
+	adafruit/Adafruit BusIO@^1.14.5
+	Wire
+	SPI
+	bblanchon/ArduinoJson@^6.21.5
+monitor_speed = 115200
diff --git a/pio/src/main.cpp b/pio/src/main.cpp
new file mode 100644
index 0000000..e7cd4e6
--- /dev/null
+++ b/pio/src/main.cpp
@@ -0,0 +1,594 @@
+#include <Arduino.h>
+#include <SPI.h>
+#include <Wire.h>
+#include <Adafruit_GFX.h>
+#include <Adafruit_SSD1306.h>
+#include <WiFi.h>
+#include <WiFiMulti.h>
+#include <HTTPClient.h>
+#include <ArduinoJson.h>
+#include <MFRC522.h>
+
+
+#define SSID "iPhone von Torben"
+#define PASSWORD "JuliaUndTorben"
+#define SCREEN_WIDTH 128 // OLED display width, in pixels
+#define SCREEN_HEIGHT 32 // OLED display height, in pixels
+#define OLED_RESET -1
+#define SCREEN_ADDRESS 0x3C ///< See datasheet for Address; 0x3D for 128x64, 0x3C for 128x32
+#define WELCOME_DELAY_MS 5000
+#define CHAR_WIDTH 6 // Assuming each character is 6 pixels wide
+#define BUTTON_PIN_1 32
+#define BUTTON_PIN_2 33
+#define BUTTON_PIN_3 25
+#define BUTTON_PIN_4 26
+#define MIN_INTERRUPT_INTERVAL 500
+#define RST_PIN 15
+#define SS_PIN 5
+#define ANON_PLAYER "Anon"
+#define ANON_PLAYER_TAG_ID "Anon"
+
+MFRC522 mfrc522(SS_PIN, RST_PIN);
+
+Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
+
+WiFiMulti wifiMulti;
+
+enum AppState
+{
+  WELCOME,
+  LOADING_PLAYERS,
+  LOAD_PLAYERS_ERROR,
+  REGISTER_PLAYER,
+  TEAM_OVERVIEW,
+  SCORE_DISPLAY,
+  SUBMIT_RESULT_QUESTION,
+  SUBMITTING_RESULT,
+  SUBMIT_RESULT_SUCCESS,
+  SUBMIT_RESULT_ERROR
+};
+
+struct Player
+{
+  String tag_id;
+  String nickname;
+};
+
+Player allPlayers[1000];
+int allPlayersCount = 0;
+
+AppState currentState = WELCOME;
+
+String player1 = ANON_PLAYER;
+String player1TagID = ANON_PLAYER_TAG_ID;
+String player2 = ANON_PLAYER;
+String player2TagID = ANON_PLAYER_TAG_ID;
+String player3 = ANON_PLAYER;
+String player3TagID = ANON_PLAYER_TAG_ID;
+String player4 = ANON_PLAYER;
+String player4TagID = ANON_PLAYER_TAG_ID;
+
+int setupPlayer = 1;
+
+int scoreA = 0;
+int scoreB = 0;
+
+bool button1Pressed = false;
+bool button2Pressed = false;
+bool button3Pressed = false;
+bool button4Pressed = false;
+
+unsigned long lastButton1Press = 0;
+unsigned long lastButton2Press = 0;
+unsigned long lastButton3Press = 0;
+unsigned long lastButton4Press = 0;
+
+void printCenteredText(String text, int y)
+{
+  int textWidth = text.length() * CHAR_WIDTH; 
+  int x = (SCREEN_WIDTH - textWidth) / 2;
+  display.setCursor(x, y);
+  display.println(text);
+}
+
+void printRegisterPlayer()
+{
+  display.clearDisplay();
+  printCenteredText("Register", 0);
+  if(setupPlayer == 1 || setupPlayer == 2) {
+    printCenteredText("Team A: Player " + String(setupPlayer), 10);
+  } else if(setupPlayer == 3 || setupPlayer == 4) {
+    printCenteredText("Team B: Player " + String(setupPlayer), 10);
+  }
+
+  if(setupPlayer == 1) {
+    if(player1 == ANON_PLAYER) {
+      printCenteredText("tag >>> reader", 20);
+    } else {
+      printCenteredText(player1, 20);
+    }
+  } else if(setupPlayer == 2) {
+    if(player2 == ANON_PLAYER) {
+      printCenteredText("tag >>> reader", 20);
+    } else {
+      printCenteredText(player2, 20);
+    }
+  } else if(setupPlayer == 3) {
+    if(player3 == ANON_PLAYER) {
+      printCenteredText("tag >>> reader", 20);
+    } else {
+      printCenteredText(player3, 20);
+    }
+  } else if(setupPlayer == 4) {
+    if(player4 == ANON_PLAYER) {
+      printCenteredText("tag >>> reader", 20);
+    } else {
+      printCenteredText(player4, 20);
+    }
+  }
+
+  display.display();
+}
+
+void showWelcome()
+{
+  display.clearDisplay();
+  printCenteredText("welcome to", 0);
+  printCenteredText("Dynatrace", 10);
+  printCenteredText("BALANKA", 20);
+  display.display();
+  delay(3000);
+}
+
+void loadPlayers()
+{
+
+  HTTPClient http;
+
+  Serial.println("[HTTP] Begin loading players...");
+
+  http.begin("https://dt-balanka.projektvorschau.at/players.php"); 
+
+  int httpCode = http.GET();
+
+
+  if (httpCode == HTTP_CODE_OK)
+  {
+    Serial.println("[HTTP] Players loaded successfully.");
+
+    String payload = http.getString();
+
+    Serial.println("[HTTP] response payload: " + payload);
+
+    Serial.println("[JSON] parsing response payload...");
+
+    DynamicJsonDocument doc(102400);
+    DeserializationError error = deserializeJson(doc, payload);
+
+    if (error)
+    {
+      Serial.println("[JSON] parse error!");
+      currentState = LOAD_PLAYERS_ERROR;
+      return;
+    }
+
+    int numLoadedPlayers = doc.size();
+    allPlayersCount = numLoadedPlayers;
+
+    for (int i = 0; i < numLoadedPlayers; i++)
+    {
+      allPlayers[i].tag_id = doc[i]["tag_id"].as<String>();
+      allPlayers[i].nickname = doc[i]["nickname"].as<String>();
+    }
+
+    Serial.println("[JSON] players parsed...");
+
+    currentState = REGISTER_PLAYER;
+  }
+    else
+  {
+    currentState = LOAD_PLAYERS_ERROR;
+    Serial.printf("[HTTP] Error loading players! Error: %s\n", http.errorToString(httpCode).c_str());
+  }
+}
+
+void printLoadPlayersError()
+{
+  display.clearDisplay();
+  printCenteredText("Error loading", 0);
+  printCenteredText("players!", 10);
+  printCenteredText("Please try again", 20);
+  display.display();
+}
+
+void IRAM_ATTR buttonOneInterrupt()
+{
+  if (millis() - lastButton1Press > MIN_INTERRUPT_INTERVAL)
+  {
+    button1Pressed = true;
+    lastButton1Press = millis();
+  }
+}
+
+void IRAM_ATTR buttonTwoInterrupt()
+{
+  if (millis() - lastButton2Press > MIN_INTERRUPT_INTERVAL)
+  {
+    button2Pressed = true;
+    lastButton2Press = millis();
+  }
+}
+
+void IRAM_ATTR buttonThreeInterrupt()
+{
+  if (millis() - lastButton3Press > MIN_INTERRUPT_INTERVAL)
+  {
+    button3Pressed = true;
+    lastButton3Press = millis();
+  }
+}
+
+void IRAM_ATTR buttonFourInterrupt()
+{
+  if (millis() - lastButton4Press > MIN_INTERRUPT_INTERVAL)
+  {
+    button4Pressed = true;
+    lastButton4Press = millis();
+  }
+}
+
+// https://forum.arduino.cc/t/convert-mfrc522-uid-to-string-byte-array-to-string/613945
+void uid_to_string(byte array[], unsigned int len, char buffer[])
+{
+  for (unsigned int i = 0; i < len; i++)
+  {
+    byte nib1 = (array[i] >> 4) & 0x0F;
+    byte nib2 = (array[i] >> 0) & 0x0F;
+    buffer[i * 2 + 0] = nib1 < 0xA ? '0' + nib1 : 'A' + nib1 - 0xA;
+    buffer[i * 2 + 1] = nib2 < 0xA ? '0' + nib2 : 'A' + nib2 - 0xA;
+  }
+  buffer[len * 2] = '\0';
+}
+
+String findNicknameByTagID(const String &searchTagID)
+{
+  for (int i = 0; i < allPlayersCount; i++)
+  {
+    if (allPlayers[i].tag_id == searchTagID)
+    {
+      return allPlayers[i].nickname; // Found a match, return the nickname
+    }
+  }
+
+  return ANON_PLAYER;
+}
+
+void RFIDReaderLoop()
+{
+  if (mfrc522.PICC_IsNewCardPresent() && mfrc522.PICC_ReadCardSerial())
+  {
+    char uid[32] = "";
+    uid_to_string(mfrc522.uid.uidByte, mfrc522.uid.size, uid);
+
+    Serial.print("UID: ");
+    Serial.println(uid);
+
+    String nickname = findNicknameByTagID(uid);
+
+    Serial.print("Nickname: ");
+    Serial.println(nickname);
+
+    if (setupPlayer == 1)
+    {
+      player1 = nickname;
+      player1TagID = uid;
+    }
+    else if (setupPlayer == 2)
+    {
+      player2 = nickname;
+      player2TagID = uid;
+    }
+    else if (setupPlayer == 3)
+    {
+      player3 = nickname;
+      player3TagID = uid;
+    }
+    else if (setupPlayer == 4)
+    {
+      player4 = nickname;
+      player4TagID = uid;
+    }
+
+    mfrc522.PICC_HaltA();
+    mfrc522.PCD_StopCrypto1();
+  }
+}
+
+void handleTeamOverviewButtonInput() 
+{
+  if(button1Pressed) {
+    Serial.println("Button 1 pressed. nothing to do");
+    button1Pressed = false;
+  }
+  if(button2Pressed) {
+    Serial.println("Button 2 pressed. Go back to register players");
+    currentState = REGISTER_PLAYER;
+    button2Pressed = false;
+  }
+  if(button3Pressed) {
+    Serial.println("Button 3 pressed. Go back to register players");
+    currentState = REGISTER_PLAYER;
+    button3Pressed = false;
+  }
+  if(button4Pressed) {
+    Serial.println("Button 4 pressed. Start game - show Score screen");
+    currentState = SCORE_DISPLAY;
+    button4Pressed = false;
+  }
+}
+
+void printScoreDisplay()
+{
+  display.clearDisplay();
+  printCenteredText(player1 + "&" + player2, 0);
+  printCenteredText(String(scoreA) + " : " + String(scoreB), 10);
+  printCenteredText(player3 + "&" + player4, 20);
+  display.display();
+}
+
+void handleScoreScreenButtonInput()
+{
+  if(button1Pressed) {
+    Serial.println("Button 1 pressed. nothing to do");
+    button1Pressed = false;
+  }
+  if(button2Pressed) {
+    Serial.println("Button 2 pressed. Add point for team A");
+    scoreA++;
+    button2Pressed = false;
+  }
+  if(button3Pressed) {
+    Serial.println("Button 3 pressed. Add point for team B");
+    scoreB++;
+    button3Pressed = false;
+  }
+  if(button4Pressed) {
+    Serial.println("Button 4 pressed. Show submit result question");
+    currentState = SUBMIT_RESULT_QUESTION;
+    button4Pressed = false;
+  }
+}
+
+void resetGame()
+{
+  showWelcome();
+  currentState = LOADING_PLAYERS;
+  player1 = ANON_PLAYER;
+  player1TagID = ANON_PLAYER_TAG_ID;
+  player2 = ANON_PLAYER;
+  player2TagID = ANON_PLAYER_TAG_ID;
+  player3 = ANON_PLAYER;
+  player3TagID = ANON_PLAYER_TAG_ID;
+  player4 = ANON_PLAYER;
+  player4TagID = ANON_PLAYER_TAG_ID;
+  scoreA = 0;
+  scoreB = 0;
+  setupPlayer = 1;
+}
+
+void printTeamOverview()
+{
+  display.clearDisplay();
+  printCenteredText("TEAMS OK?", 0);
+  printCenteredText(player1 + " & " + player2, 10);
+  printCenteredText(player3 + " & " + player4, 20);
+  display.display();
+}
+
+  void setup()
+  {
+    Serial.begin(115200);
+
+    Wire.begin(21, 22);
+
+    // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
+    if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS))
+    {
+      Serial.println("Screen Error: SSD1306 allocation failed");
+      for (;;)
+        ; // Don't proceed, loop forever
+    }
+
+    // set display settings
+    display.clearDisplay();
+    display.setTextSize(1);
+    display.setTextColor(WHITE);
+
+    // initialize buttons
+    pinMode(BUTTON_PIN_1, INPUT_PULLUP);
+    pinMode(BUTTON_PIN_2, INPUT_PULLUP);
+    pinMode(BUTTON_PIN_3, INPUT_PULLUP);
+    pinMode(BUTTON_PIN_4, INPUT_PULLUP);
+
+    attachInterrupt(digitalPinToInterrupt(BUTTON_PIN_1), buttonOneInterrupt, FALLING);
+    attachInterrupt(digitalPinToInterrupt(BUTTON_PIN_2), buttonTwoInterrupt, FALLING);
+    attachInterrupt(digitalPinToInterrupt(BUTTON_PIN_3), buttonThreeInterrupt, FALLING);
+    attachInterrupt(digitalPinToInterrupt(BUTTON_PIN_4), buttonFourInterrupt, FALLING);
+
+    // initialize RFID reader
+    SPI.begin();
+    mfrc522.PCD_Init();
+
+    // setup WiFi
+    wifiMulti.addAP(SSID, PASSWORD);
+
+    // show welcome screen, reset game
+    resetGame();
+  }
+
+  void printSubmitResultQuestion()
+  {
+    display.clearDisplay();
+    printCenteredText("Submit result?", 0);
+    printCenteredText("A: " + String(scoreA) + ", B: " + String(scoreB), 10);
+    display.display();
+  }
+
+  void handleResultQuestionButtonInput()
+  {
+    if(button1Pressed) {
+      Serial.println("Button 1 pressed. nothing to do");
+      button1Pressed = false;
+    }
+    if(button2Pressed) {
+      Serial.println("Button 2 pressed. Back to score screen");
+      currentState = SCORE_DISPLAY;
+      button2Pressed = false;
+    }
+    if(button3Pressed) {
+      Serial.println("Button 3 pressed. Back to score screen");
+      currentState = SCORE_DISPLAY;
+      button3Pressed = false;
+    }
+    if(button4Pressed) {
+      Serial.println("Button 4 pressed. Submit result");
+      currentState = SUBMITTING_RESULT;
+      button4Pressed = false;
+    }
+  }
+
+  void handleRegisterPlayerButtonInput()
+  {
+    if (button1Pressed)
+    {
+      Serial.println("Button 1 pressed. nothing to do");
+      button1Pressed = false;
+    }
+    if (button2Pressed)
+    {
+      Serial.println("Button 2 pressed. Switch to previous player");
+      if (setupPlayer > 1)
+      {
+        setupPlayer--;
+      } else {
+      setupPlayer = 4;
+    }
+    button2Pressed = false;
+  }
+  if (button3Pressed)
+  {
+    Serial.println("Button 3 pressed. Switch to next player");
+    if(setupPlayer < 4) {
+      setupPlayer++;
+    } else {
+      setupPlayer = 1;
+    }
+    button3Pressed = false;
+  }
+  if (button4Pressed)
+  {
+    Serial.println("Button 4 pressed. Show Team configuration");
+    currentState = TEAM_OVERVIEW;
+    button4Pressed = false;
+  }
+}
+
+void printSubmitResultSuccess()
+{
+  display.clearDisplay();
+  printCenteredText("Result submitted", 0);
+  printCenteredText("successfully!", 10);
+  display.display();
+}
+
+void handleResultScreenButtonInput() {
+  // reset state if any button pressed and show welcome screen and then register players
+  if(button1Pressed || button2Pressed || button3Pressed || button4Pressed) {
+    Serial.println("Button pressed. Resetting state");
+    resetGame();
+  }
+}
+
+void submitResult()
+{
+  HTTPClient http;
+
+  Serial.println("[HTTP] Begin submitting result...");
+
+  http.begin("http://dt-balanka.projektvorschau.at/results.php");
+
+  http.addHeader("Content-Type", "application/json");
+
+  String payload = "{ \"tap1\": \"" + player1TagID + "\", \"tap2\": \"" + player2TagID + "\", \"tbp1\": \"" + player3TagID + "\", \"tbp2\": \"" + player4TagID + "\", \"score_a\": " + String(scoreA) + ", \"score_b\": " + String(scoreB) + " }";
+
+  Serial.println("[HTTP] payload: " + payload);
+
+  int httpCode = http.POST(payload);
+
+  if (httpCode == HTTP_CODE_OK)
+  {
+    Serial.println("[HTTP] Result submitted successfully.");
+    currentState = SUBMIT_RESULT_SUCCESS;
+  }
+  else
+  {
+    currentState = SUBMIT_RESULT_ERROR;
+    Serial.printf("[HTTP] Error submitting result! Error: %s\n", http.errorToString(httpCode).c_str());
+  }
+}
+
+void printSubmitResultError()
+{
+  display.clearDisplay();
+  printCenteredText("Error submitting", 0);
+  printCenteredText("result!", 10);
+  display.display();
+}
+
+    void
+    loop()
+{
+  switch(currentState) {
+    case WELCOME:
+      resetGame();
+      break;
+    case LOADING_PLAYERS:
+      if (wifiMulti.run() == WL_CONNECTED)
+      {
+        loadPlayers();
+      }
+      break;
+    case LOAD_PLAYERS_ERROR:
+      printLoadPlayersError();
+      delay(1000);
+      break;
+    case REGISTER_PLAYER:
+      printRegisterPlayer();
+      handleRegisterPlayerButtonInput();
+      RFIDReaderLoop();
+      break;
+    case TEAM_OVERVIEW:
+      printTeamOverview();
+      handleTeamOverviewButtonInput();
+      break;
+    case SCORE_DISPLAY:
+      printScoreDisplay();
+      handleScoreScreenButtonInput();
+      break;
+    case SUBMIT_RESULT_QUESTION:
+      printSubmitResultQuestion();
+      handleResultQuestionButtonInput();
+      break;
+    case SUBMITTING_RESULT:
+      submitResult();
+      break;
+    case SUBMIT_RESULT_SUCCESS:
+      printSubmitResultSuccess();
+      handleResultScreenButtonInput();
+      break;
+    case SUBMIT_RESULT_ERROR:
+      printSubmitResultError();
+      handleResultScreenButtonInput();
+      break;
+    }
+}
diff --git a/pio/test/README b/pio/test/README
new file mode 100644
index 0000000..b0416ad
--- /dev/null
+++ b/pio/test/README
@@ -0,0 +1,11 @@
+
+This directory is intended for PlatformIO Test Runner and project tests.
+
+Unit Testing is a software testing method by which individual units of
+source code, sets of one or more MCU program modules together with associated
+control data, usage procedures, and operating procedures, are tested to
+determine whether they are fit for use. Unit testing finds problems early
+in the development cycle.
+
+More information about PlatformIO Unit Testing:
+- https://docs.platformio.org/en/latest/advanced/unit-testing/index.html