diff --git a/firmware/ArduinoTest/Def_InOut_PrepLogic/Def_InOut_PrepLogic.ino b/firmware/ArduinoTest/Def_InOut_PrepLogic/Def_InOut_PrepLogic.ino
new file mode 100644
index 0000000..d16db3b
--- /dev/null
+++ b/firmware/ArduinoTest/Def_InOut_PrepLogic/Def_InOut_PrepLogic.ino
@@ -0,0 +1,217 @@
+/*
+  0004_DenshaBekutoru – Optocoupler Averaging Test
+  Target dev board (later): Arduino Pro Mini 5V / 16 MHz (ATmega328P)
+
+  Measures average voltage on:
+   - A2 -> later ATtiny85 PB3 (XTAL1, Pin 2)
+   - A3 -> later ATtiny85 PB4 (XTAL2, Pin 3)
+
+  Boot calibration:
+   - assumes "no movement" at startup
+   - measures V1/V2 AverageRepeat times
+   - computes di = |V1 - V2| each time
+   - VdiffBaseline = median(di)
+   - VdiffThreshold = max(VdiffBaseline * VdiffThresholdMargin, VdiffThresholdMinVolts)
+*/
+
+const unsigned long SAMPLE_WINDOW_MS = 100;   // averaging window per measurement
+const unsigned long SAMPLE_DELAY_US  = 500;   // delay between ADC samples (~2 kHz)
+
+const uint8_t ADC_PIN_1 = A2;  // Pro Mini A2 -> later ATtiny85 PB3 (XTAL1, Pin 2)
+const uint8_t ADC_PIN_2 = A3;  // Pro Mini A3 -> later ATtiny85 PB4 (XTAL2, Pin 3)
+
+// LEDs for direction indication (avoid D0/D1)
+const uint8_t LED_DIR1_PIN = 2;  // D2
+const uint8_t LED_DIR2_PIN = 3;  // D3
+
+// Serial output control (0 = no output, 1 = output)
+bool SerialOutputAllow = true;
+
+// ---- Calibration parameters ----
+const uint16_t AverageRepeat = 100;          // number of init measurements
+const float VdiffThresholdMargin = 1.50f;    // multiplier (e.g., 1.5 = +50% margin)
+const float VdiffThresholdMinVolts = 0.03f;  // floor in volts (optional but practical)
+
+// Globals: latest measured averaged voltages
+float v1 = 0.0f;
+float v2 = 0.0f;
+
+// Calibration globals
+float VdiffBaseline = 0.0f;   // median(|V1-V2|) measured at boot (no movement)
+float VdiffThreshold = 0.0f;  // final threshold used for direction decision
+
+// Direction encoding requirement:
+// 0 = no direction
+// 2 = direction 1 (maps to LED pin D2)
+// 3 = direction 2 (maps to LED pin D3)
+byte direction = 0;
+
+static inline float absf(float x) { return (x >= 0.0f) ? x : -x; }
+static inline float maxf(float a, float b) { return (a > b) ? a : b; }
+
+static void applyDirectionOutputs()
+{
+  digitalWrite(LED_DIR1_PIN, LOW);
+  digitalWrite(LED_DIR2_PIN, LOW);
+
+  if (direction == LED_DIR1_PIN) {
+    digitalWrite(LED_DIR1_PIN, HIGH);
+  } else if (direction == LED_DIR2_PIN) {
+    digitalWrite(LED_DIR2_PIN, HIGH);
+  }
+}
+
+// Measure averaged voltages (updates globals v1/v2)
+static void measureAveragedVoltages()
+{
+  unsigned long startTime = millis();
+
+  unsigned long sum1 = 0;
+  unsigned long sum2 = 0;
+  unsigned long samples = 0;
+
+  while (millis() - startTime < SAMPLE_WINDOW_MS) {
+    sum1 += analogRead(ADC_PIN_1);
+    sum2 += analogRead(ADC_PIN_2);
+    samples++;
+    delayMicroseconds(SAMPLE_DELAY_US);
+  }
+
+  float avg1 = (float)sum1 / samples;
+  float avg2 = (float)sum2 / samples;
+
+  // Convert ADC value to voltage (default analog reference = Vcc ~ 5V)
+  v1 = avg1 * (5.0f / 1023.0f);
+  v2 = avg2 * (5.0f / 1023.0f);
+}
+
+static void sortFloatArray(float *a, uint16_t n)
+{
+  // Insertion sort (n=100 is small, OK)
+  for (uint16_t i = 1; i < n; i++) {
+    float key = a[i];
+    int16_t j = (int16_t)i - 1;
+    while (j >= 0 && a[j] > key) {
+      a[j + 1] = a[j];
+      j--;
+    }
+    a[j + 1] = key;
+  }
+}
+
+static float medianOfSortedFloatArray(const float *a, uint16_t n)
+{
+  if (n == 0) return 0.0f;
+  if (n & 1) {
+    return a[n / 2];
+  } else {
+    return (a[(n / 2) - 1] + a[n / 2]) * 0.5f;
+  }
+}
+
+// Calibrate baseline + threshold once at boot/reset
+// Parameter must be only AverageRepeat (per your requirement).
+static void calibrateVdiffThreshold(uint16_t averageRepeat)
+{
+  if (averageRepeat < 1) averageRepeat = 1;
+  if (averageRepeat > 200) averageRepeat = 200; // RAM safety cap
+
+  float diffs[200];
+
+  for (uint16_t i = 0; i < averageRepeat; i++) {
+    measureAveragedVoltages();
+    diffs[i] = absf(v1 - v2); // baseline mismatch sample
+  }
+
+  sortFloatArray(diffs, averageRepeat);
+  VdiffBaseline = medianOfSortedFloatArray(diffs, averageRepeat);
+
+  // Final threshold with margin + floor
+  VdiffThreshold = maxf(VdiffBaseline * VdiffThresholdMargin, VdiffThresholdMinVolts);
+}
+
+static void updateDirectionFromVoltages()
+{
+  float diff = v1 - v2;
+  float absDiff = absf(diff);
+
+  if (absDiff <= VdiffThreshold) {
+    direction = 0;
+  } else {
+    // Mapping choice:
+    // v1 lower than v2 -> direction 1 (D2)
+    // v2 lower than v1 -> direction 2 (D3)
+    direction = (diff < 0.0f) ? LED_DIR1_PIN : LED_DIR2_PIN;
+  }
+}
+
+static void serialPrintAll()
+{
+  if (!SerialOutputAllow) return;
+
+  Serial.print("A2 for PB3  XTAL1, Pin2: ");
+  Serial.print(v1, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("A3 for PB4 XTAL2, Pin3: ");
+  Serial.print(v2, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("|V1-V2|: ");
+  Serial.print(absf(v1 - v2), 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("VdiffBaseline: ");
+  Serial.print(VdiffBaseline, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("VdiffThresholdMargin: ");
+  Serial.print(VdiffThresholdMargin, 2);
+  Serial.print(" x   |   ");
+
+  Serial.print("VdiffThresholdMinVolts: ");
+  Serial.print(VdiffThresholdMinVolts, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("VdiffThreshold: ");
+  Serial.print(VdiffThreshold, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("direction: ");
+  Serial.println(direction);
+}
+
+void setup() {
+  Serial.begin(115200);
+
+  pinMode(ADC_PIN_1, INPUT);
+  pinMode(ADC_PIN_2, INPUT);
+
+  pinMode(LED_DIR1_PIN, OUTPUT);
+  pinMode(LED_DIR2_PIN, OUTPUT);
+
+  calibrateVdiffThreshold(AverageRepeat);
+
+  // One measurement for initial output + outputs
+  measureAveragedVoltages();
+  updateDirectionFromVoltages();
+  applyDirectionOutputs();
+
+  if (SerialOutputAllow) {
+    Serial.println("=== DenshaBekutoru Optocoupler Average Test (Arduino Pro Mini 5V/16MHz) ===");
+    Serial.print("AverageRepeat: ");
+    Serial.println(AverageRepeat);
+  }
+
+  serialPrintAll();
+}
+
+void loop() {
+  measureAveragedVoltages();
+  updateDirectionFromVoltages();
+  applyDirectionOutputs();
+
+  serialPrintAll();
+
+  delay(300);
+}
diff --git a/firmware/ArduinoTest/enshaBekutoru_0004___Version_0.1_UnoTest/enshaBekutoru_0004___Version_0.1_UnoTest.ino b/firmware/ArduinoTest/enshaBekutoru_0004___Version_0.1_UnoTest/enshaBekutoru_0004___Version_0.1_UnoTest.ino
new file mode 100644
index 0000000..99054a7
--- /dev/null
+++ b/firmware/ArduinoTest/enshaBekutoru_0004___Version_0.1_UnoTest/enshaBekutoru_0004___Version_0.1_UnoTest.ino
@@ -0,0 +1,292 @@
+/*
+  0004_DenshaBekutoru – Version 0.1 Test
+  Target dev board (later): Arduino Pro Mini 5V / 16 MHz (ATmega328P)
+
+  ----------------------------------------------------------------------------
+  State machine (direction memory)
+  ----------------------------------------------------------------------------
+  Inputs derived from v1, v2, VdiffThreshold:
+
+    N (Neutral):  |v1 - v2| <= VdiffThreshold
+    D1 (v1>>v2):  (v1 - v2) >  VdiffThreshold
+    D2 (v2>>v1):  (v2 - v1) >  VdiffThreshold
+
+  State encoding:
+    0 = NONE
+    2 = DIR1
+    3 = DIR2
+
+  Transition table:
+
+    Current \ Input |   N (neutral)   |   D1 (v1>>v2) |   D2 (v2>>v1)
+    -----------------------------------------------------------------
+       0 (NONE)     |      0          |       2       |       3
+       2 (DIR1)     |      2          |       2       |       3
+       3 (DIR2)     |      3          |       2       |       3
+
+  Mermaid (documentation)
+  -----------------------
+  stateDiagram-v2
+      [*] --> NONE
+      state "0 : NONE" as NONE
+      state "2 : DIR1 (v1>>v2)" as DIR1
+      state "3 : DIR2 (v2>>v1)" as DIR2
+
+      NONE --> NONE : |v1 - v2| <= T
+      NONE --> DIR1 : v1 - v2 > T
+      NONE --> DIR2 : v2 - v1 > T
+
+      DIR1 --> DIR1 : |v1 - v2| <= T
+      DIR1 --> DIR1 : v1 - v2 > T
+      DIR1 --> DIR2 : v2 - v1 > T
+
+      DIR2 --> DIR2 : |v1 - v2| <= T
+      DIR2 --> DIR2 : v2 - v1 > T
+      DIR2 --> DIR1 : v1 - v2 > T
+*/
+
+const unsigned long SAMPLE_WINDOW_MS = 100;   // averaging window per measurement
+const unsigned long SAMPLE_DELAY_US  = 500;   // delay between ADC samples (~2 kHz)
+
+const uint8_t ADC_PIN_1 = A2;  // Pro Mini A2 -> later ATtiny85 PB3 (XTAL1, Pin 2)
+const uint8_t ADC_PIN_2 = A3;  // Pro Mini A3 -> later ATtiny85 PB4 (XTAL2, Pin 3)
+
+// Direction LEDs (avoid D0/D1 because you may want RX/TX later)
+const uint8_t LED_DIR1_PIN = 2;  // D2
+const uint8_t LED_DIR2_PIN = 3;  // D3
+
+const unsigned int LED_BLINK_ON_MS  = 150;
+const unsigned int LED_BLINK_OFF_MS = 150;
+
+// Serial output control (0 = no output, 1 = output)
+bool SerialOutputAllow = true;
+
+// ---- Calibration parameters ----
+const uint16_t AverageRepeat = 100;          // number of init measurements
+const float VdiffThresholdMargin = 1.50f;    // multiplier (e.g., 1.5 = +50% margin)
+const float VdiffThresholdMinVolts = 0.03f;  // floor in volts
+
+// Globals: latest measured averaged voltages
+float v1 = 0.0f;
+float v2 = 0.0f;
+
+// Calibration globals
+float VdiffBaseline = 0.0f;   // median(|V1-V2|) measured at boot (no movement)
+float VdiffThreshold = 0.0f;  // final threshold used for direction decision
+
+// Direction encoding:
+// 0 = NONE, 2 = DIR1, 3 = DIR2
+byte direction = 0;
+
+static inline float absf(float x) { return (x >= 0.0f) ? x : -x; }
+static inline float maxf(float a, float b) { return (a > b) ? a : b; }
+
+// -----------------------------------------------------------------------------
+// LED helpers
+// -----------------------------------------------------------------------------
+static void blinkLED(uint8_t pin, uint8_t times)
+{
+  for (uint8_t i = 0; i < times; i++) {
+    digitalWrite(pin, HIGH);
+    delay(LED_BLINK_ON_MS);
+    digitalWrite(pin, LOW);
+    delay(LED_BLINK_OFF_MS);
+  }
+}
+
+static void initBlinkSequence()
+{
+  // LED at Output 2 blinks 2 times
+  blinkLED(LED_DIR1_PIN, 2);
+
+  // LED at Output 3 blinks 3 times
+  blinkLED(LED_DIR2_PIN, 3);
+}
+
+static void applyDirectionOutputs()
+{
+  digitalWrite(LED_DIR1_PIN, LOW);
+  digitalWrite(LED_DIR2_PIN, LOW);
+
+  if (direction == 2) {
+    digitalWrite(LED_DIR1_PIN, HIGH);
+  } else if (direction == 3) {
+    digitalWrite(LED_DIR2_PIN, HIGH);
+  }
+}
+
+// -----------------------------------------------------------------------------
+// Measurement
+// -----------------------------------------------------------------------------
+static void measureAveragedVoltages()
+{
+  unsigned long startTime = millis();
+
+  unsigned long sum1 = 0;
+  unsigned long sum2 = 0;
+  unsigned long samples = 0;
+
+  while (millis() - startTime < SAMPLE_WINDOW_MS) {
+    sum1 += analogRead(ADC_PIN_1);
+    sum2 += analogRead(ADC_PIN_2);
+    samples++;
+    delayMicroseconds(SAMPLE_DELAY_US);
+  }
+
+  float avg1 = (float)sum1 / samples;
+  float avg2 = (float)sum2 / samples;
+
+  // Convert ADC value to voltage (default analog reference = Vcc ~ 5V)
+  v1 = avg1 * (5.0f / 1023.0f);
+  v2 = avg2 * (5.0f / 1023.0f);
+}
+
+// -----------------------------------------------------------------------------
+// Median helpers (for calibration)
+// -----------------------------------------------------------------------------
+static void sortFloatArray(float *a, uint16_t n)
+{
+  // Insertion sort (n=100 is small, OK)
+  for (uint16_t i = 1; i < n; i++) {
+    float key = a[i];
+    int16_t j = (int16_t)i - 1;
+    while (j >= 0 && a[j] > key) {
+      a[j + 1] = a[j];
+      j--;
+    }
+    a[j + 1] = key;
+  }
+}
+
+static float medianOfSortedFloatArray(const float *a, uint16_t n)
+{
+  if (n == 0) return 0.0f;
+  if (n & 1) {
+    return a[n / 2];
+  } else {
+    return (a[(n / 2) - 1] + a[n / 2]) * 0.5f;
+  }
+}
+
+// Calibrate baseline + threshold once at boot/reset
+// Parameter must be only AverageRepeat.
+static void calibrateVdiffThreshold(uint16_t averageRepeat)
+{
+  if (averageRepeat < 1) averageRepeat = 1;
+  if (averageRepeat > 200) averageRepeat = 200; // RAM safety cap
+
+  float diffs[200];
+
+  for (uint16_t i = 0; i < averageRepeat; i++) {
+    measureAveragedVoltages();
+    diffs[i] = absf(v1 - v2); // baseline mismatch sample
+  }
+
+  sortFloatArray(diffs, averageRepeat);
+  VdiffBaseline = medianOfSortedFloatArray(diffs, averageRepeat);
+
+  // Final threshold with margin + floor
+  VdiffThreshold = maxf(VdiffBaseline * VdiffThresholdMargin, VdiffThresholdMinVolts);
+}
+
+// -----------------------------------------------------------------------------
+// State machine
+// -----------------------------------------------------------------------------
+static void updateDirectionFromVoltages()
+{
+  const float diff = v1 - v2;
+  const float absDiff = absf(diff);
+
+  // Neutral region: hold direction
+  if (absDiff <= VdiffThreshold) {
+    return;
+  }
+
+  // Clear dominance: set direction deterministically
+  // diff > 0  => v1 >> v2 => DIR1 (2)
+  // diff < 0  => v2 >> v1 => DIR2 (3)
+  direction = (diff > 0.0f) ? (byte)2 : (byte)3;
+}
+
+// -----------------------------------------------------------------------------
+// Serial output
+// -----------------------------------------------------------------------------
+static void serialPrintAll()
+{
+  if (!SerialOutputAllow) return;
+
+  Serial.print("A2 for PB3  XTAL1, Pin2: ");
+  Serial.print(v1, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("A3 for PB4 XTAL2, Pin3: ");
+  Serial.print(v2, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("|V1-V2|: ");
+  Serial.print(absf(v1 - v2), 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("VdiffBaseline: ");
+  Serial.print(VdiffBaseline, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("VdiffThresholdMargin: ");
+  Serial.print(VdiffThresholdMargin, 2);
+  Serial.print(" x   |   ");
+
+  Serial.print("VdiffThresholdMinVolts: ");
+  Serial.print(VdiffThresholdMinVolts, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("VdiffThreshold: ");
+  Serial.print(VdiffThreshold, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("direction: ");
+  Serial.println(direction);
+}
+
+// -----------------------------------------------------------------------------
+// Arduino entry points
+// -----------------------------------------------------------------------------
+void setup() {
+  Serial.begin(115200);
+
+  pinMode(ADC_PIN_1, INPUT);
+  pinMode(ADC_PIN_2, INPUT);
+
+  pinMode(LED_DIR1_PIN, OUTPUT);
+  pinMode(LED_DIR2_PIN, OUTPUT);
+
+  // Initial calibration (assumes no movement)
+  calibrateVdiffThreshold(AverageRepeat);
+
+  // Init blink sequence: 2x on D2, 3x on D3
+  initBlinkSequence();
+
+  // One measurement for initial display + initial direction
+  measureAveragedVoltages();
+  updateDirectionFromVoltages();
+  applyDirectionOutputs();
+
+  if (SerialOutputAllow) {
+    Serial.println("=== DenshaBekutoru 0004 – Version 0.1 Test (Arduino Uno Test) ===");
+    Serial.println("  ~~~ InitStart ~~~");
+    Serial.print("  AverageRepeat: "); 
+    Serial.println(AverageRepeat);
+    Serial.println("  ~~~ InitEnd  ~~~");
+  }
+
+  serialPrintAll();
+}
+
+void loop() {
+  measureAveragedVoltages();
+  updateDirectionFromVoltages();
+  applyDirectionOutputs();
+
+  serialPrintAll();
+
+  delay(300);
+}
diff --git a/firmware/ArduinoTest/enshaBekutoru_0004___Version_0.2_UnoTest/enshaBekutoru_0004___Version_0.2_UnoTest.ino b/firmware/ArduinoTest/enshaBekutoru_0004___Version_0.2_UnoTest/enshaBekutoru_0004___Version_0.2_UnoTest.ino
new file mode 100644
index 0000000..c89378e
--- /dev/null
+++ b/firmware/ArduinoTest/enshaBekutoru_0004___Version_0.2_UnoTest/enshaBekutoru_0004___Version_0.2_UnoTest.ino
@@ -0,0 +1,286 @@
+/*
+  0004_DenshaBekutoru – Optocoupler Averaging Test
+  Target dev board (later): Arduino Pro Mini 5V / 16 MHz (ATmega328P)
+
+  ----------------------------------------------------------------------------
+  State machine (direction memory) + Hysteresis (Version A)
+  ----------------------------------------------------------------------------
+  We use two thresholds:
+    T_hold  (smaller): below -> treat as neutral and HOLD state
+    T_enter (larger): above -> allow direction change (set by sign)
+
+  Behavior:
+    If |diff| <= T_hold : hold direction
+    If |diff| >= T_enter: set direction by sign
+    Else (between)      : hold direction
+
+  Presets (implemented as multipliers of the calibrated VdiffThreshold):
+    T_hold  = 1.0 * VdiffThreshold
+    T_enter = 2.0 * VdiffThreshold
+
+  Inputs derived from v1, v2:
+    diff = v1 - v2
+*/
+
+const unsigned long SAMPLE_WINDOW_MS = 100;   // averaging window per measurement
+const unsigned long SAMPLE_DELAY_US  = 500;   // delay between ADC samples (~2 kHz)
+
+const uint8_t ADC_PIN_1 = A2;  // Pro Mini A2 -> later ATtiny85 PB3 (XTAL1, Pin 2)
+const uint8_t ADC_PIN_2 = A3;  // Pro Mini A3 -> later ATtiny85 PB4 (XTAL2, Pin 3)
+
+// Direction LEDs (avoid D0/D1 because you may want RX/TX later)
+const uint8_t LED_DIR1_PIN = 2;  // D2
+const uint8_t LED_DIR2_PIN = 3;  // D3
+
+const unsigned int LED_BLINK_ON_MS  = 150;
+const unsigned int LED_BLINK_OFF_MS = 150;
+
+// Serial output control (0 = no output, 1 = output)
+bool SerialOutputAllow = true;
+
+// ---- Calibration parameters ----
+const uint16_t AverageRepeat = 100;          // number of init measurements
+const float VdiffThresholdMargin = 1.50f;    // multiplier (e.g., 1.5 = +50% margin)
+const float VdiffThresholdMinVolts = 0.03f;  // floor in volts
+
+// ---- Hysteresis presets (multipliers of VdiffThreshold) ----
+const float THOLD_MULT  = 1.0f;  // T_hold  = THOLD_MULT  * VdiffThreshold
+const float TENTER_MULT = 2.0f;  // T_enter = TENTER_MULT * VdiffThreshold
+
+// Globals: latest measured averaged voltages
+float v1 = 0.0f;
+float v2 = 0.0f;
+
+// Calibration globals
+float VdiffBaseline = 0.0f;   // median(|V1-V2|) measured at boot (no movement)
+float VdiffThreshold = 0.0f;  // calibrated base threshold (used to derive T_hold/T_enter)
+
+// Hysteresis thresholds (derived once after calibration)
+float T_hold  = 0.0f;
+float T_enter = 0.0f;
+
+// Direction encoding:
+// 0 = NONE, 2 = DIR1, 3 = DIR2
+byte direction = 0;
+
+static inline float absf(float x) { return (x >= 0.0f) ? x : -x; }
+static inline float maxf(float a, float b) { return (a > b) ? a : b; }
+
+// -----------------------------------------------------------------------------
+// LED helpers
+// -----------------------------------------------------------------------------
+static void blinkLED(uint8_t pin, uint8_t times)
+{
+  for (uint8_t i = 0; i < times; i++) {
+    digitalWrite(pin, HIGH);
+    delay(LED_BLINK_ON_MS);
+    digitalWrite(pin, LOW);
+    delay(LED_BLINK_OFF_MS);
+  }
+}
+
+static void initBlinkSequence()
+{
+  // LED at Output 2 blinks 2 times
+  blinkLED(LED_DIR1_PIN, 2);
+
+  // LED at Output 3 blinks 3 times
+  blinkLED(LED_DIR2_PIN, 3);
+}
+
+static void applyDirectionOutputs()
+{
+  digitalWrite(LED_DIR1_PIN, LOW);
+  digitalWrite(LED_DIR2_PIN, LOW);
+
+  if (direction == 2) {
+    digitalWrite(LED_DIR1_PIN, HIGH);
+  } else if (direction == 3) {
+    digitalWrite(LED_DIR2_PIN, HIGH);
+  }
+}
+
+// -----------------------------------------------------------------------------
+// Measurement
+// -----------------------------------------------------------------------------
+static void measureAveragedVoltages()
+{
+  unsigned long startTime = millis();
+
+  unsigned long sum1 = 0;
+  unsigned long sum2 = 0;
+  unsigned long samples = 0;
+
+  while (millis() - startTime < SAMPLE_WINDOW_MS) {
+    sum1 += analogRead(ADC_PIN_1);
+    sum2 += analogRead(ADC_PIN_2);
+    samples++;
+    delayMicroseconds(SAMPLE_DELAY_US);
+  }
+
+  float avg1 = (float)sum1 / samples;
+  float avg2 = (float)sum2 / samples;
+
+  // Convert ADC value to voltage (default analog reference = Vcc ~ 5V)
+  v1 = avg1 * (5.0f / 1023.0f);
+  v2 = avg2 * (5.0f / 1023.0f);
+}
+
+// -----------------------------------------------------------------------------
+// Median helpers (for calibration)
+// -----------------------------------------------------------------------------
+static void sortFloatArray(float *a, uint16_t n)
+{
+  // Insertion sort (n=100 is small, OK)
+  for (uint16_t i = 1; i < n; i++) {
+    float key = a[i];
+    int16_t j = (int16_t)i - 1;
+    while (j >= 0 && a[j] > key) {
+      a[j + 1] = a[j];
+      j--;
+    }
+    a[j + 1] = key;
+  }
+}
+
+static float medianOfSortedFloatArray(const float *a, uint16_t n)
+{
+  if (n == 0) return 0.0f;
+  if (n & 1) {
+    return a[n / 2];
+  } else {
+    return (a[(n / 2) - 1] + a[n / 2]) * 0.5f;
+  }
+}
+
+// Calibrate baseline + VdiffThreshold once at boot/reset
+static void calibrateVdiffThreshold(uint16_t averageRepeat)
+{
+  if (averageRepeat < 1) averageRepeat = 1;
+  if (averageRepeat > 200) averageRepeat = 200; // RAM safety cap
+
+  float diffs[200];
+
+  for (uint16_t i = 0; i < averageRepeat; i++) {
+    measureAveragedVoltages();
+    diffs[i] = absf(v1 - v2); // baseline mismatch sample
+  }
+
+  sortFloatArray(diffs, averageRepeat);
+  VdiffBaseline = medianOfSortedFloatArray(diffs, averageRepeat);
+
+  // Calibrated base threshold with margin + floor
+  VdiffThreshold = maxf(VdiffBaseline * VdiffThresholdMargin, VdiffThresholdMinVolts);
+
+  // Derive hysteresis thresholds (Version A)
+  T_hold  = THOLD_MULT  * VdiffThreshold;
+  T_enter = TENTER_MULT * VdiffThreshold;
+}
+
+// -----------------------------------------------------------------------------
+// State machine with hysteresis (Version A)
+// -----------------------------------------------------------------------------
+static void updateDirectionFromVoltages()
+{
+  const float diff = v1 - v2;
+  const float absDiff = absf(diff);
+
+  // 1) Neutral region: HOLD
+  if (absDiff <= T_hold) {
+    return;
+  }
+
+  // 2) Strong region: allow direction change
+  if (absDiff >= T_enter) {
+    direction = (diff > 0.0f) ? (byte)2 : (byte)3;
+    return;
+  }
+
+  // 3) Deadband between T_hold and T_enter: HOLD
+  return;
+}
+
+// -----------------------------------------------------------------------------
+// Serial output
+// -----------------------------------------------------------------------------
+static void serialPrintAll()
+{
+  if (!SerialOutputAllow) return;
+
+  Serial.print("A2 for PB3  XTAL1, Pin2: ");
+  Serial.print(v1, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("A3 for PB4 XTAL2, Pin3: ");
+  Serial.print(v2, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("|V1-V2|: ");
+  Serial.print(absf(v1 - v2), 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("VdiffBaseline: ");
+  Serial.print(VdiffBaseline, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("VdiffThreshold: ");
+  Serial.print(VdiffThreshold, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("T_hold: ");
+  Serial.print(T_hold, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("T_enter: ");
+  Serial.print(T_enter, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("direction: ");
+  Serial.println(direction);
+}
+
+// -----------------------------------------------------------------------------
+// Arduino entry points
+// -----------------------------------------------------------------------------
+void setup() {
+  Serial.begin(115200);
+
+  pinMode(ADC_PIN_1, INPUT);
+  pinMode(ADC_PIN_2, INPUT);
+
+  pinMode(LED_DIR1_PIN, OUTPUT);
+  pinMode(LED_DIR2_PIN, OUTPUT);
+
+  // Initial calibration (assumes no movement)
+  calibrateVdiffThreshold(AverageRepeat);
+
+  // Init blink sequence: 2x on D2, 3x on D3
+  initBlinkSequence();
+
+  // One measurement for initial display + initial direction
+  measureAveragedVoltages();
+  updateDirectionFromVoltages();
+  applyDirectionOutputs();
+
+  if (SerialOutputAllow) {
+    Serial.println("=== DenshaBekutoru Optocoupler Average Test (Arduino Pro Mini 5V/16MHz) ===");
+    Serial.print("AverageRepeat: ");
+    Serial.println(AverageRepeat);
+    Serial.print("THOLD_MULT: ");
+    Serial.print(THOLD_MULT, 2);
+    Serial.print("   TENTER_MULT: ");
+    Serial.println(TENTER_MULT, 2);
+  }
+
+  serialPrintAll();
+}
+
+void loop() {
+  measureAveragedVoltages();
+  updateDirectionFromVoltages();
+  applyDirectionOutputs();
+
+  serialPrintAll();
+
+  delay(300);
+}
diff --git a/firmware/ArduinoTest/implementstatemachine/implementstatemachine.ino b/firmware/ArduinoTest/implementstatemachine/implementstatemachine.ino
new file mode 100644
index 0000000..9d9b116
--- /dev/null
+++ b/firmware/ArduinoTest/implementstatemachine/implementstatemachine.ino
@@ -0,0 +1,231 @@
+/*
+  0004_DenshaBekutoru – State Machine implemented
+  Target dev board (later): Arduino Pro Mini 5V / 16 MHz (ATmega328P)
+
+  ----------------------------------------------------------------------------
+  State machine (direction memory)
+  ----------------------------------------------------------------------------
+  Inputs derived from v1, v2, VdiffThreshold:
+
+    N (Neutral):  |v1 - v2| <= VdiffThreshold
+    D1 (v1>>v2):  (v1 - v2) >  VdiffThreshold
+    D2 (v2>>v1):  (v2 - v1) >  VdiffThreshold
+
+  State encoding (kept transfer-friendly, and compatible with earlier pin-mapping):
+    0 = NONE
+    2 = DIR1
+    3 = DIR2
+
+  Transition table:
+
+    Current \ Input |   N (neutral)   |   D1 (v1>>v2) |   D2 (v2>>v1)
+    -----------------------------------------------------------------
+       0 (NONE)     |      0          |       2       |       3
+       2 (DIR1)     |      2          |       2       |       3
+       3 (DIR2)     |      3          |       2       |       3
+
+  Mermaid (documentation)
+  -----------------------
+  stateDiagram-v2
+      [*] --> NONE
+      state "0 : NONE" as NONE
+      state "2 : DIR1 (v1>>v2)" as DIR1
+      state "3 : DIR2 (v2>>v1)" as DIR2
+
+      NONE --> NONE : |v1 - v2| <= T
+      NONE --> DIR1 : v1 - v2 > T
+      NONE --> DIR2 : v2 - v1 > T
+
+      DIR1 --> DIR1 : |v1 - v2| <= T
+      DIR1 --> DIR1 : v1 - v2 > T
+      DIR1 --> DIR2 : v2 - v1 > T
+
+      DIR2 --> DIR2 : |v1 - v2| <= T
+      DIR2 --> DIR2 : v2 - v1 > T
+      DIR2 --> DIR1 : v1 - v2 > T
+*/
+
+const unsigned long SAMPLE_WINDOW_MS = 100;   // averaging window per measurement
+const unsigned long SAMPLE_DELAY_US  = 500;   // delay between ADC samples (~2 kHz)
+
+const uint8_t ADC_PIN_1 = A2;  // Pro Mini A2 -> later ATtiny85 PB3 (XTAL1, Pin 2)
+const uint8_t ADC_PIN_2 = A3;  // Pro Mini A3 -> later ATtiny85 PB4 (XTAL2, Pin 3)
+
+// Serial output control (0 = no output, 1 = output)
+bool SerialOutputAllow = true;
+
+// ---- Calibration parameters ----
+const uint16_t AverageRepeat = 100;          // number of init measurements
+const float VdiffThresholdMargin = 1.50f;    // multiplier (e.g., 1.5 = +50% margin)
+const float VdiffThresholdMinVolts = 0.03f;  // floor in volts (optional but practical)
+
+// Globals: latest measured averaged voltages
+float v1 = 0.0f;
+float v2 = 0.0f;
+
+// Calibration globals
+float VdiffBaseline = 0.0f;   // median(|V1-V2|) measured at boot (no movement)
+float VdiffThreshold = 0.0f;  // final threshold used for direction decision
+
+// Direction encoding:
+// 0 = NONE, 2 = DIR1, 3 = DIR2
+byte direction = 0;
+
+static inline float absf(float x) { return (x >= 0.0f) ? x : -x; }
+static inline float maxf(float a, float b) { return (a > b) ? a : b; }
+
+// Measure averaged voltages (updates globals v1/v2)
+static void measureAveragedVoltages()
+{
+  unsigned long startTime = millis();
+
+  unsigned long sum1 = 0;
+  unsigned long sum2 = 0;
+  unsigned long samples = 0;
+
+  while (millis() - startTime < SAMPLE_WINDOW_MS) {
+    sum1 += analogRead(ADC_PIN_1);
+    sum2 += analogRead(ADC_PIN_2);
+    samples++;
+    delayMicroseconds(SAMPLE_DELAY_US);
+  }
+
+  float avg1 = (float)sum1 / samples;
+  float avg2 = (float)sum2 / samples;
+
+  // Convert ADC value to voltage (default analog reference = Vcc ~ 5V)
+  v1 = avg1 * (5.0f / 1023.0f);
+  v2 = avg2 * (5.0f / 1023.0f);
+}
+
+static void sortFloatArray(float *a, uint16_t n)
+{
+  // Insertion sort (n=100 is small, OK)
+  for (uint16_t i = 1; i < n; i++) {
+    float key = a[i];
+    int16_t j = (int16_t)i - 1;
+    while (j >= 0 && a[j] > key) {
+      a[j + 1] = a[j];
+      j--;
+    }
+    a[j + 1] = key;
+  }
+}
+
+static float medianOfSortedFloatArray(const float *a, uint16_t n)
+{
+  if (n == 0) return 0.0f;
+  if (n & 1) {
+    return a[n / 2];
+  } else {
+    return (a[(n / 2) - 1] + a[n / 2]) * 0.5f;
+  }
+}
+
+// Calibrate baseline + threshold once at boot/reset
+// Parameter must be only AverageRepeat (per your requirement).
+static void calibrateVdiffThreshold(uint16_t averageRepeat)
+{
+  if (averageRepeat < 1) averageRepeat = 1;
+  if (averageRepeat > 200) averageRepeat = 200; // RAM safety cap
+
+  float diffs[200];
+
+  for (uint16_t i = 0; i < averageRepeat; i++) {
+    measureAveragedVoltages();
+    diffs[i] = absf(v1 - v2); // baseline mismatch sample
+  }
+
+  sortFloatArray(diffs, averageRepeat);
+  VdiffBaseline = medianOfSortedFloatArray(diffs, averageRepeat);
+
+  // Final threshold with margin + floor
+  VdiffThreshold = maxf(VdiffBaseline * VdiffThresholdMargin, VdiffThresholdMinVolts);
+}
+
+// Implements the state machine table above
+static void updateDirectionFromVoltages()
+{
+  const float diff = v1 - v2;
+  const float absDiff = absf(diff);
+
+  // Neutral region: hold direction (only NONE stays NONE)
+  if (absDiff <= VdiffThreshold) {
+    // direction remains unchanged (0 stays 0; 2 stays 2; 3 stays 3)
+    return;
+  }
+
+  // Clear dominance: set direction deterministically
+  // diff > 0  => v1 >> v2 => DIR1 (2)
+  // diff < 0  => v2 >> v1 => DIR2 (3)
+  direction = (diff > 0.0f) ? (byte)2 : (byte)3;
+}
+
+static void serialPrintAll()
+{
+  if (!SerialOutputAllow) return;
+
+  Serial.print("A2 for PB3  XTAL1, Pin2: ");
+  Serial.print(v1, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("A3 for PB4 XTAL2, Pin3: ");
+  Serial.print(v2, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("|V1-V2|: ");
+  Serial.print(absf(v1 - v2), 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("VdiffBaseline: ");
+  Serial.print(VdiffBaseline, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("VdiffThresholdMargin: ");
+  Serial.print(VdiffThresholdMargin, 2);
+  Serial.print(" x   |   ");
+
+  Serial.print("VdiffThresholdMinVolts: ");
+  Serial.print(VdiffThresholdMinVolts, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("VdiffThreshold: ");
+  Serial.print(VdiffThreshold, 3);
+  Serial.print(" V   |   ");
+
+  Serial.print("direction: ");
+  Serial.println(direction);
+}
+
+void setup() {
+  Serial.begin(115200);
+
+  pinMode(ADC_PIN_1, INPUT);
+  pinMode(ADC_PIN_2, INPUT);
+
+  // Initial calibration: compute VdiffThreshold once after boot/reset
+  calibrateVdiffThreshold(AverageRepeat);
+
+  // One measurement for initial display
+  measureAveragedVoltages();
+  updateDirectionFromVoltages();
+
+  if (SerialOutputAllow) {
+    Serial.println("=== DenshaBekutoru State Machine and Variable Output (Arduino Pro Mini 5V/16MHz) ===");
+    Serial.println("~~~ Init ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
+    Serial.print("AverageRepeat: ");
+    Serial.println(AverageRepeat);
+    Serial.println("~~~ Init ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
+  }
+
+  serialPrintAll();
+}
+
+void loop() {
+  measureAveragedVoltages();
+  updateDirectionFromVoltages();
+
+  serialPrintAll();
+
+  delay(300);
+}