diff --git a/OpticalChannelTester/App.cpp b/OpticalChannelTester/App.cpp
index 393ab23..d273212 100644
--- a/OpticalChannelTester/App.cpp
+++ b/OpticalChannelTester/App.cpp
@@ -17,7 +17,7 @@ namespace {
 const char *uiFailName(FailReason reason);
 
 const char *appStateName(AppState state) {
-  static const char *names[] = {"IDLE", "MENU", "SOLO_MEASURE", "SOLO_DRIVER", "MASTER_DISCOVER",
+  static const char *names[] = {"IDLE", "MENU", "BOARD_TEST", "SOLO_MEASURE", "SOLO_DRIVER", "MASTER_DISCOVER",
     "MASTER_WAIT_READY", "MASTER_WAIT_RESULT", "MASTER_FINALIZE", "SLAVE_READY", "SLAVE_WAIT_START",
     "SLAVE_MEASURE", "SLAVE_WAIT_ACK", "FINISHED"};
   const uint8_t index = static_cast<uint8_t>(state);
@@ -145,6 +145,30 @@ const char *uiTestName(TestKind kind) {
     ? UiText::TEST_NAMES[index] : "?";
 }
 
+const char *uiTestGroupName(TestGroup group) {
+  const uint8_t index = static_cast<uint8_t>(group);
+  return index < sizeof(UiText::TEST_GROUP_NAMES) / sizeof(UiText::TEST_GROUP_NAMES[0])
+    ? UiText::TEST_GROUP_NAMES[index] : "?";
+}
+
+const char *uiBoardTestName(BoardTest test) {
+  const uint8_t index = static_cast<uint8_t>(test);
+  return index < sizeof(UiText::BOARD_TEST_NAMES) / sizeof(UiText::BOARD_TEST_NAMES[0])
+    ? UiText::BOARD_TEST_NAMES[index] : "?";
+}
+
+bool boardTestAvailable(BoardTest test) {
+  if (test == BoardTest::PWM_OUTPUT) return true;
+  if (test == BoardTest::ADC) return BOARD_RX_USES_ADC && BOARD_ADC_AVAILABLE;
+  if (test == BoardTest::RX_INPUT) return !BOARD_RX_USES_ADC;
+  return false;
+}
+
+BoardTest defaultBoardTest() {
+  return BOARD_RX_USES_ADC && BOARD_ADC_AVAILABLE
+    ? BoardTest::ADC : BoardTest::RX_INPUT;
+}
+
 uint8_t lastValidMaxPulseIndex(uint32_t frequencyHz) {
   uint8_t last = static_cast<uint8_t>(countOf(MAX_PULSE_OPTIONS_NS) - 1U);
   while (last && static_cast<uint64_t>(MAX_PULSE_OPTIONS_NS[last]) * frequencyHz >= 1000000000ULL)
@@ -290,7 +314,8 @@ void App::finishInitialization(bool factoryReset) {
   lastUserActivityMs_ = millis();
   setActivePerformance(false);
   printConfiguration();
-  if (static_cast<Role>(settings_.role) == Role::SLAVE) armSlave();
+  if (static_cast<TestGroup>(settings_.testGroup) == TestGroup::OPTICS &&
+      static_cast<Role>(settings_.role) == Role::SLAVE) armSlave();
   else showIdle();
 }
 
@@ -313,7 +338,15 @@ void App::update() {
     else if (now - bootCheckStartedMs_ >= FACTORY_RESET_HOLD_MS) finishInitialization(true);
     return;
   }
-  serviceRxPinStateLog();
+  if (state_ == AppState::BOARD_TEST) {
+    if (startEvent == ButtonEvent::LONG) stopBoardTest();
+    else {
+      if (modeEvent != ButtonEvent::NONE)
+        Log::event("ACTION", "MODE ignored while board test is active");
+      updateBoardTest(now);
+    }
+    return;
+  }
   if (state_ != AppState::IDLE && state_ != AppState::MENU && state_ != AppState::FINISHED &&
       startEvent == ButtonEvent::LONG) { abortTest(); return; }
   if (state_ != AppState::IDLE && state_ != AppState::MENU && state_ != AppState::FINISHED &&
@@ -323,12 +356,16 @@ void App::update() {
     if (modeEvent == ButtonEvent::SHORT) {
       cycleRunMode(); sanitizeRange(); const bool saved = store_.save(settings_);
       params_ = store_.params(settings_);
-      if (static_cast<Role>(settings_.role) == Role::SLAVE) armSlave();
+      if (static_cast<TestGroup>(settings_.testGroup) == TestGroup::OPTICS &&
+          static_cast<Role>(settings_.role) == Role::SLAVE) armSlave();
       else showIdle();
-      Log::printf("ACTION", "mode changed to %s/%s, NVS=%s",
-        roleName(static_cast<Role>(settings_.role)),
-        testKindName(static_cast<TestKind>(settings_.testKind)),
-        saved ? "OK" : "FAILED");
+      if (static_cast<TestGroup>(settings_.testGroup) == TestGroup::BOARD)
+        Log::printf("ACTION", "board test changed to %s, NVS=%s",
+          boardTestName(static_cast<BoardTest>(settings_.boardTest)), saved ? "OK" : "FAILED");
+      else
+        Log::printf("ACTION", "mode changed to %s/%s, NVS=%s",
+          roleName(static_cast<Role>(settings_.role)),
+          testKindName(static_cast<TestKind>(settings_.testKind)), saved ? "OK" : "FAILED");
     } else if (modeEvent == ButtonEvent::LONG) {
       state_ = AppState::MENU; menuItem_ = 0; Log::event("ACTION", "settings menu entered"); showMenu();
     } else if (startEvent == ButtonEvent::SHORT) { Log::event("ACTION", "test start requested"); startTest(); }
@@ -351,13 +388,15 @@ void App::update() {
   }
   if (state_ == AppState::MENU) {
     if (modeEvent == ButtonEvent::SHORT) {
-      menuItem_ = (menuItem_ + 1U) % 6U; Log::printf("ACTION", "menu item selected index=%u", menuItem_); showMenu();
+      const uint8_t menuCount = static_cast<TestGroup>(settings_.testGroup) == TestGroup::BOARD ? 1U : 7U;
+      menuItem_ = (menuItem_ + 1U) % menuCount; Log::printf("ACTION", "menu item selected index=%u", menuItem_); showMenu();
     }
     else if (modeEvent == ButtonEvent::LONG) {
       sanitizeRange(); const bool saved = store_.save(settings_); params_ = store_.params(settings_);
       Log::printf("ACTION", "settings menu saved and closed, NVS=%s", saved ? "OK" : "FAILED");
       state_ = AppState::IDLE; printConfiguration();
-      if (static_cast<Role>(settings_.role) == Role::SLAVE) armSlave();
+      if (static_cast<TestGroup>(settings_.testGroup) == TestGroup::OPTICS &&
+          static_cast<Role>(settings_.role) == Role::SLAVE) armSlave();
       else showIdle();
     } else if (startEvent == ButtonEvent::SHORT) changeMenu(+1);
     else if (startEvent == ButtonEvent::LONG || startEvent == ButtonEvent::REPEAT) changeMenu(-1);
@@ -429,10 +468,17 @@ void App::showIdle() {
   setActivePerformance(false);
   setStandbyOpticalOutput();
   lastUserActivityMs_ = millis();
-  char one[64]; snprintf(one, sizeof(one), "%s: %s",
-    uiRoleName(static_cast<Role>(settings_.role)),
-    uiTestName(static_cast<TestKind>(settings_.testKind)));
-  display_.show(one, UiText::START_RUN);
+  char one[64];
+  if (static_cast<TestGroup>(settings_.testGroup) == TestGroup::BOARD) {
+    snprintf(one, sizeof(one), "%s: %s", uiTestGroupName(TestGroup::BOARD),
+      uiBoardTestName(static_cast<BoardTest>(settings_.boardTest)));
+    display_.show(one, UiText::BOARD_READY);
+  } else {
+    snprintf(one, sizeof(one), "%s: %s",
+      uiRoleName(static_cast<Role>(settings_.role)),
+      uiTestName(static_cast<TestKind>(settings_.testKind)));
+    display_.show(one, UiText::START_RUN);
+  }
 }
 
 void App::serviceSerialConsole() {
@@ -464,6 +510,8 @@ void App::serviceSerialConsole() {
 void App::printSerialHelp() {
   Serial.println("COMMANDS (send with newline):");
   Serial.println("  help | status | start | stop | defaults");
+  Serial.println("  set group optics|board");
+  Serial.println("  set boardtest adc|pwm|rx");
   Serial.println("  set role solo|master|slave");
   Serial.println("  set test optical|driver");
   Serial.println("  set frequency 500|1000|2000|5000|10000|25000");
@@ -480,8 +528,9 @@ void App::printSerialStatus() {
     return;
   }
   params_ = store_.params(settings_);
-  Serial.printf("STATUS state=%s role=%s test=%s frequency=%luHz max=%luns min=%luns accuracy=%.2f%% time=%lums light=%s usb=%s\n",
-    appStateName(state_), roleName(static_cast<Role>(settings_.role)),
+  Serial.printf("STATUS state=%s group=%s boardtest=%s role=%s test=%s frequency=%luHz max=%luns min=%luns accuracy=%.2f%% time=%lums light=%s usb=%s\n",
+    appStateName(state_), testGroupName(static_cast<TestGroup>(settings_.testGroup)),
+    boardTestName(static_cast<BoardTest>(settings_.boardTest)), roleName(static_cast<Role>(settings_.role)),
     testKindName(static_cast<TestKind>(settings_.testKind)), params_.frequencyHz,
     params_.maxPulseNs, params_.minPulseNs, params_.accuracyPct, params_.testTimeMs,
     configuredLevelName(settings_),
@@ -501,7 +550,8 @@ void App::finishSerialSettingsChange() {
   pwm_.configureActiveLight(configuredTxPulseLightOn(settings_));
   const bool saved = store_.save(settings_);
   Serial.printf("OK settings saved=%s\n", saved ? "yes" : "no");
-  if (static_cast<Role>(settings_.role) == Role::SLAVE) armSlave();
+  if (static_cast<TestGroup>(settings_.testGroup) == TestGroup::OPTICS &&
+      static_cast<Role>(settings_.role) == Role::SLAVE) armSlave();
   else showIdle();
   printSerialStatus();
 }
@@ -535,7 +585,10 @@ void App::handleSerialCommand(char *line) {
   if ((!strcmp(command, "stop") || !strcmp(command, "abort")) && !name) {
     if (!initialized_) Serial.println("ERR still initializing");
     else if (state_ == AppState::IDLE || state_ == AppState::FINISHED) Serial.println("OK already stopped");
-    else if (state_ == AppState::MENU) {
+    else if (state_ == AppState::BOARD_TEST) {
+      Serial.println("OK board test stopped");
+      stopBoardTest();
+    } else if (state_ == AppState::MENU) {
       state_ = AppState::IDLE; showIdle(); Serial.println("OK menu closed");
     } else if (state_ == AppState::SLAVE_READY) Serial.println("OK slave is armed; no test is running");
     else {
@@ -564,7 +617,22 @@ void App::handleSerialCommand(char *line) {
 
   bool accepted = false;
   uint32_t numeric = 0;
-  if (!strcmp(name, "role")) {
+  if (!strcmp(name, "group")) {
+    if (!strcmp(value, "optics") || !strcmp(value, "optical")) {
+      settings_.testGroup = static_cast<uint8_t>(TestGroup::OPTICS); accepted = true;
+    } else if (!strcmp(value, "board")) {
+      settings_.testGroup = static_cast<uint8_t>(TestGroup::BOARD); accepted = true;
+    }
+  } else if (!strcmp(name, "boardtest") || !strcmp(name, "board")) {
+    BoardTest selected = static_cast<BoardTest>(UINT8_MAX);
+    if (!strcmp(value, "adc")) selected = BoardTest::ADC;
+    else if (!strcmp(value, "pwm")) selected = BoardTest::PWM_OUTPUT;
+    else if (!strcmp(value, "rx")) selected = BoardTest::RX_INPUT;
+    if (boardTestAvailable(selected)) {
+      settings_.boardTest = static_cast<uint8_t>(selected);
+      accepted = true;
+    }
+  } else if (!strcmp(name, "role")) {
     if (!strcmp(value, "solo")) { settings_.role = static_cast<uint8_t>(Role::SOLO); accepted = true; }
     else if (!strcmp(value, "master")) { settings_.role = static_cast<uint8_t>(Role::MASTER); accepted = true; }
     else if (!strcmp(value, "slave")) { settings_.role = static_cast<uint8_t>(Role::SLAVE); accepted = true; }
@@ -608,6 +676,13 @@ void App::handleSerialCommand(char *line) {
 }
 
 void App::cycleRunMode() {
+  if (static_cast<TestGroup>(settings_.testGroup) == TestGroup::BOARD) {
+    do {
+      settings_.boardTest = (settings_.boardTest + 1U) %
+        (static_cast<uint8_t>(BoardTest::RX_INPUT) + 1U);
+    } while (!boardTestAvailable(static_cast<BoardTest>(settings_.boardTest)));
+    return;
+  }
   const Role role = static_cast<Role>(settings_.role);
   const TestKind kind = static_cast<TestKind>(settings_.testKind);
   if (role == Role::SOLO && kind == TestKind::OPTICAL && !TARGET_IS_C3) {
@@ -625,6 +700,11 @@ void App::cycleRunMode() {
 }
 
 void App::sanitizeRange() {
+  if (settings_.testGroup > static_cast<uint8_t>(TestGroup::BOARD))
+    settings_.testGroup = static_cast<uint8_t>(TestGroup::OPTICS);
+  if (settings_.boardTest > static_cast<uint8_t>(BoardTest::RX_INPUT) ||
+      !boardTestAvailable(static_cast<BoardTest>(settings_.boardTest)))
+    settings_.boardTest = static_cast<uint8_t>(defaultBoardTest());
   if (settings_.role > static_cast<uint8_t>(Role::SLAVE))
     settings_.role = static_cast<uint8_t>(Role::SOLO);
   if (settings_.testKind > static_cast<uint8_t>(TestKind::DRIVER))
@@ -654,29 +734,19 @@ void App::sanitizeRange() {
   }
 }
 
-void App::serviceRxPinStateLog() {
-#ifdef RX_PIN_CHANGE_TEST
-  const bool level = digitalRead(GPIO_RX) == HIGH;
-  const bool outsideTest = state_ == AppState::IDLE || state_ == AppState::MENU ||
-    state_ == AppState::SLAVE_READY || state_ == AppState::FINISHED;
-  if (rxPinStateKnown_ && level != rxPinState_ && outsideTest)
-    Log::printf("RX TEST", "GPIO=%u state=%s (%u)", GPIO_RX,
-      level ? "HIGH" : "LOW", level ? 1U : 0U);
-  rxPinState_ = level;
-  rxPinStateKnown_ = true;
-#endif
-}
-
 void App::changeMenu(int d) {
   sanitizeRange();
-  if (menuItem_ == 1) {
+  if (menuItem_ == 0) {
+    settings_.testGroup = cycleIndex(settings_.testGroup, 0,
+      static_cast<uint8_t>(TestGroup::BOARD), d);
+  } else if (menuItem_ == 2) {
     const uint8_t last = lastValidMaxPulseIndex(
       PWM_FREQUENCY_OPTIONS_HZ[settings_.frequencyIndex]);
     const uint8_t first = firstMaxPulseIndexAtLeast(
       MIN_PULSE_OPTIONS_NS[settings_.minPulseIndex], last);
     settings_.maxPulseIndex = cycleIndex(settings_.maxPulseIndex,
       first, last, d);
-  } else if (menuItem_ == 2) {
+  } else if (menuItem_ == 3) {
     const uint8_t last = lastMinPulseIndexAtMost(
       MAX_PULSE_OPTIONS_NS[settings_.maxPulseIndex]);
     const uint8_t first = static_cast<TestKind>(settings_.testKind) == TestKind::DRIVER
@@ -685,10 +755,10 @@ void App::changeMenu(int d) {
   } else {
     uint8_t *value = nullptr; size_t count = 0;
     switch (menuItem_) {
-      case 0: value = &settings_.frequencyIndex; count = countOf(PWM_FREQUENCY_OPTIONS_HZ); break;
-      case 3: value = &settings_.accuracyIndex; count = countOf(ACCURACY_OPTIONS_PCT); break;
-      case 4: value = &settings_.timeIndex; count = countOf(TEST_TIME_OPTIONS_MS); break;
-      case 5:
+      case 1: value = &settings_.frequencyIndex; count = countOf(PWM_FREQUENCY_OPTIONS_HZ); break;
+      case 4: value = &settings_.accuracyIndex; count = countOf(ACCURACY_OPTIONS_PCT); break;
+      case 5: value = &settings_.timeIndex; count = countOf(TEST_TIME_OPTIONS_MS); break;
+      case 6:
         if (static_cast<TestKind>(settings_.testKind) != TestKind::DRIVER) {
           showMenu();
           return;
@@ -713,26 +783,31 @@ void App::showMenu() {
   Display::formatDuration(actualNominalTotalUs(), all, sizeof(all));
   switch (menuItem_) {
     case 0:
+      snprintf(value, sizeof(value), "%s",
+        uiTestGroupName(static_cast<TestGroup>(settings_.testGroup)));
+      label = UiText::MENU_TEST_GROUP;
+      break;
+    case 1:
       Display::formatPwmFrequency(params_.frequencyHz, value, sizeof(value));
       label = UiText::MENU_FREQUENCY;
       break;
-    case 1:
+    case 2:
       Display::formatPulse(params_.maxPulseNs, value, sizeof(value));
       label = UiText::MENU_MAX_PULSE;
       break;
-    case 2:
+    case 3:
       Display::formatPulse(params_.minPulseNs, value, sizeof(value));
       label = UiText::MENU_MIN_PULSE;
       break;
-    case 3:
+    case 4:
       snprintf(value, sizeof(value), "+/-%g%%", params_.accuracyPct);
       label = UiText::MENU_ACCURACY;
       break;
-    case 4:
+    case 5:
       snprintf(value, sizeof(value), "%.1fs", params_.testTimeMs / 1000.0f);
       label = UiText::MENU_TEST_TIME;
       break;
-    case 5: {
+    case 6: {
       if (static_cast<TestKind>(settings_.testKind) != TestKind::DRIVER) {
         snprintf(value, sizeof(value), "%s", UiText::LIGHT_AUTO);
         label = UiText::MENU_LIGHT_CODE;
@@ -751,7 +826,10 @@ void App::showMenu() {
     default: return;
   }
   formatMenuLine(label, value, one, sizeof(one));
-  formatMenuLine(UiText::MENU_TOTAL_TIME, all, total, sizeof(total));
+  if (static_cast<TestGroup>(settings_.testGroup) == TestGroup::BOARD)
+    snprintf(total, sizeof(total), "%s", UiText::BOARD_READY);
+  else
+    formatMenuLine(UiText::MENU_TOTAL_TIME, all, total, sizeof(total));
   display_.show(one, total);
 }
 
@@ -760,6 +838,10 @@ void App::startTest() {
   pwm_.stop();
   setActivePerformance(true);
   sanitizeRange();
+  if (static_cast<TestGroup>(settings_.testGroup) == TestGroup::BOARD) {
+    startBoardTest();
+    return;
+  }
   params_ = store_.params(settings_); stageCount_ = pulseWidthPointCount(params_.maxPulseNs, params_.minPulseNs);
   stageIndex_ = 0; requestedHz_ = params_.frequencyHz; requestedPulseNs_ = 0; pendingReason_ = FailReason::NONE;
   havePeer_ = false; lastHeartbeatMs_ = 0; lastPeerSeenMs_ = 0;
@@ -787,6 +869,98 @@ void App::startTest() {
   else { state_ = AppState::SLAVE_READY; Log::event("TEST", "Slave armed and waiting for Master"); display_.show(UiText::SLAVE_READY, UiText::WAIT_MASTER); }
 }
 
+void App::startBoardTest() {
+  const BoardTest test = static_cast<BoardTest>(settings_.boardTest);
+  state_ = AppState::BOARD_TEST;
+  boardTestUpdatedMs_ = boardDisplayUpdatedMs_ = 0;
+  boardPwmLightOn_ = false;
+  rxPinStateKnown_ = false;
+  Log::printf("BOARD", "starting test=%s", boardTestName(test));
+
+  // ADC and RX checks need the optical transmitter continuously illuminated.
+  // The PWM-output check drives the same pin itself and therefore replaces
+  // the constant active level with its test waveform.
+  if (test != BoardTest::PWM_OUTPUT) {
+    pwm_.lightOn();
+    Log::printf("BOARD", "optical output active GPIO=%u level=%s", GPIO_PWM,
+      TX_LIGHT_ON_GPIO_LEVEL == HIGH ? "HIGH" : "LOW");
+  }
+
+  if (test == BoardTest::ADC) {
+    if (!BOARD_ADC_AVAILABLE) {
+      Serial.println("BOARD ADC: unavailable in MAKETKA profile");
+      display_.show(UiText::ADC_UNAVAILABLE, UiText::BOARD_STOP);
+      return;
+    }
+    pinMode(GPIO_ANALOG_RX, INPUT);
+    pinMode(GPIO_VBAT, INPUT);
+    display_.show(UiText::BOARD_TEST_NAMES[static_cast<uint8_t>(BoardTest::ADC)],
+      UiText::BOARD_STOP);
+  } else if (test == BoardTest::PWM_OUTPUT) {
+    boardPwmLightOn_ = true;
+    boardTestUpdatedMs_ = millis();
+    pwm_.lightOn();
+    Serial.printf("BOARD PWM: GPIO=%u frequency=%luHz duty=50%% light=ON\n",
+      GPIO_PWM, BOARD_PWM_TEST_FREQUENCY_HZ);
+    display_.show(UiText::BOARD_TEST_NAMES[static_cast<uint8_t>(test)], UiText::BOARD_STOP);
+  } else {
+    pinMode(GPIO_RX, INPUT);
+    display_.show(UiText::BOARD_TEST_NAMES[static_cast<uint8_t>(test)], UiText::BOARD_STOP);
+  }
+}
+
+void App::updateBoardTest(uint32_t now) {
+  const BoardTest test = static_cast<BoardTest>(settings_.boardTest);
+  if (test == BoardTest::ADC) {
+    if (!BOARD_ADC_AVAILABLE || now - boardTestUpdatedMs_ < BOARD_ADC_PRINT_INTERVAL_MS) return;
+    boardTestUpdatedMs_ = now;
+    const uint16_t analogRx = analogRead(GPIO_ANALOG_RX);
+    const uint16_t vbat = analogRead(GPIO_VBAT);
+    Serial.printf("ADC analog_rx=%u vbat=%u\n", analogRx, vbat);
+    if (now - boardDisplayUpdatedMs_ >= BOARD_TEST_DISPLAY_INTERVAL_MS) {
+      boardDisplayUpdatedMs_ = now;
+      char one[32], two[32];
+      snprintf(one, sizeof(one), "ADC RX: %u", analogRx);
+      snprintf(two, sizeof(two), "ADC VBAT: %u", vbat);
+      display_.show(one, two);
+    }
+    return;
+  }
+
+  if (test == BoardTest::PWM_OUTPUT) {
+    if (now - boardTestUpdatedMs_ < BOARD_PWM_TEST_HALF_PERIOD_MS) return;
+    boardTestUpdatedMs_ = now;
+    boardPwmLightOn_ = !boardPwmLightOn_;
+    if (boardPwmLightOn_) pwm_.lightOn();
+    else pwm_.stop();
+    Serial.printf("BOARD PWM: light=%s\n", boardPwmLightOn_ ? "ON" : "OFF");
+    char two[32];
+    snprintf(two, sizeof(two), "%luHz 50%%: %s", BOARD_PWM_TEST_FREQUENCY_HZ,
+      boardPwmLightOn_ ? "ON" : "OFF");
+    display_.show(UiText::BOARD_TEST_NAMES[static_cast<uint8_t>(test)], two);
+    return;
+  }
+
+  const bool level = digitalRead(GPIO_RX) == HIGH;
+  if (!rxPinStateKnown_ || level != rxPinState_) {
+    rxPinState_ = level;
+    rxPinStateKnown_ = true;
+    Serial.printf("RX GPIO=%u state=%s (%u)\n", GPIO_RX,
+      level ? "HIGH" : "LOW", level ? 1U : 0U);
+    char two[32];
+    snprintf(two, sizeof(two), "GPIO %u: %s", GPIO_RX, level ? "HIGH" : "LOW");
+    display_.show(UiText::BOARD_TEST_NAMES[static_cast<uint8_t>(test)], two);
+  }
+}
+
+void App::stopBoardTest() {
+  Log::printf("BOARD", "stopping test=%s", boardTestName(static_cast<BoardTest>(settings_.boardTest)));
+  pwm_.stop();
+  state_ = AppState::IDLE;
+  setActivePerformance(false);
+  showIdle();
+}
+
 bool App::armSlave(bool preserveDisplay) {
   setActivePerformance(false);
   pwm_.stop();
@@ -1291,13 +1465,15 @@ bool App::usbHostPresent() const {
 void App::setStandbyOpticalOutput() {
   // A gate driver must never be held enabled while the tester is idle or
   // showing a result. DRIVER is SOLO-only, so force real light OFF here.
-  if (static_cast<Role>(settings_.role) == Role::SLAVE ||
+  if (static_cast<TestGroup>(settings_.testGroup) == TestGroup::BOARD ||
+      static_cast<Role>(settings_.role) == Role::SLAVE ||
       static_cast<TestKind>(settings_.testKind) == TestKind::DRIVER) pwm_.stop();
   else pwm_.active();
 }
 
 void App::setActivePerformance(bool active) {
   const bool driverMode = initialized_ &&
+    static_cast<TestGroup>(settings_.testGroup) == TestGroup::OPTICS &&
     static_cast<TestKind>(settings_.testKind) == TestKind::DRIVER;
   const uint32_t targetMhz = active ? (driverMode ? 240U : 160U) : 80U;
   if (getCpuFrequencyMhz() != targetMhz && !setCpuFrequencyMhz(targetMhz))
@@ -1406,7 +1582,15 @@ void App::printConfiguration() {
   if (SERIAL_MINIMAL_LOG) return;
   const char *board = TARGET_IS_C3 ? "ESP32-C3" : "ESP32-S3";
   uint8_t mac[6] = {}; esp_read_mac(mac, ESP_MAC_WIFI_STA);
-  Serial.printf("\nOptical Channel Tester | %s | mode=%s/%s | light=%s\n", board,
+  if (static_cast<TestGroup>(settings_.testGroup) == TestGroup::BOARD) {
+    Serial.printf("\nOptical Channel Tester | %s | group=BOARD | test=%s\n", board,
+      boardTestName(static_cast<BoardTest>(settings_.boardTest)));
+    Serial.printf("GPIO PWM=%u RX=%u ANALOG_RX=%u VBAT=%u START=%u MODE=%u SDA=%u SCL=%u\n",
+      GPIO_PWM, GPIO_RX, GPIO_ANALOG_RX, GPIO_VBAT, GPIO_BUTTON_START,
+      GPIO_BUTTON_MODE, GPIO_SDA, GPIO_SCL);
+    return;
+  }
+  Serial.printf("\nOptical Channel Tester | %s | group=OPTICS | mode=%s/%s | light=%s\n", board,
     roleName(static_cast<Role>(settings_.role)),
     testKindName(static_cast<TestKind>(settings_.testKind)),
     configuredLevelName(settings_));
diff --git a/OpticalChannelTester/App.h b/OpticalChannelTester/App.h
index b3da243..674d1ac 100644
--- a/OpticalChannelTester/App.h
+++ b/OpticalChannelTester/App.h
@@ -8,7 +8,7 @@
 #include "SettingsStore.h"
 
 enum class AppState : uint8_t {
-  IDLE, MENU, SOLO_MEASURE, SOLO_DRIVER, MASTER_DISCOVER, MASTER_WAIT_READY,
+  IDLE, MENU, BOARD_TEST, SOLO_MEASURE, SOLO_DRIVER, MASTER_DISCOVER, MASTER_WAIT_READY,
   MASTER_WAIT_RESULT, MASTER_FINALIZE, SLAVE_READY, SLAVE_WAIT_START, SLAVE_MEASURE,
   SLAVE_WAIT_ACK, FINISHED
 };
@@ -26,6 +26,9 @@ class App {
   void cycleRunMode();
   void sanitizeRange();
   void startTest();
+  void startBoardTest();
+  void updateBoardTest(uint32_t now);
+  void stopBoardTest();
   bool armSlave(bool preserveDisplay = false);
   bool prepareStage(bool showProgress = true);
   bool startLocalMeasurement(float hz, float duty);
@@ -52,7 +55,6 @@ class App {
   void updateHeartbeat();
   bool packetForCurrent(const ProtocolPacket &p) const;
   void serviceIdlePowerSave();
-  void serviceRxPinStateLog();
   void serviceSerialConsole();
   void handleSerialCommand(char *line);
   void printSerialHelp();
@@ -100,6 +102,9 @@ class App {
   uint32_t lastOpticalWakeToggleMs_ = 0;
   bool opticalWakeActive_ = false;
   bool rxPinStateKnown_ = false, rxPinState_ = false;
+  uint32_t boardTestUpdatedMs_ = 0;
+  uint32_t boardDisplayUpdatedMs_ = 0;
+  bool boardPwmLightOn_ = false;
   mutable uint32_t lastUsbHostSeenMs_ = 0;
   char serialLine_[96] = {};
   uint8_t serialLineLength_ = 0;
diff --git a/OpticalChannelTester/Config.h b/OpticalChannelTester/Config.h
index c2efc6b..63fb912 100644
--- a/OpticalChannelTester/Config.h
+++ b/OpticalChannelTester/Config.h
@@ -5,29 +5,43 @@
 // ------------------------- Hardware configuration -------------------------
 // Enabled for the hand-wired prototype. Comment out for the production PCB.
 // Both profiles map S3 signals by physical header position with 5V/GND aligned.
-#define MAKETKA
+//#define MAKETKA
 
-// Additionally log raw GPIO_RX level changes while no test is running.
-//#define RX_PIN_CHANGE_TEST
+// Select exactly one populated receiver circuit. Use
+// BOARD_RX_INTERFACE_DIGITAL for MAKETKA and boards fitted with GPIO_RX.
+#define BOARD_RX_INTERFACE_ADC 1
+#define BOARD_RX_INTERFACE_DIGITAL 2
+#define BOARD_RX_INTERFACE BOARD_RX_INTERFACE_ADC
 
-// Standalone PWM output check. While enabled, the normal application is not
-// started: GPIO_PWM continuously outputs the frequency and duty below.
-// Comment this define out after the hardware check.
-//#define PWM_OUTPUT_TEST
-constexpr uint32_t PWM_OUTPUT_TEST_FREQUENCY_HZ = 1000;
-constexpr uint32_t PWM_OUTPUT_TEST_SWEEP_PERIOD_MS = 2000;
-constexpr uint32_t PWM_OUTPUT_TEST_UPDATE_MS = 10;
-constexpr uint32_t PWM_OUTPUT_TEST_MIN_PULSE_NS = 1000;
-constexpr uint32_t PWM_OUTPUT_TEST_MAX_PULSE_NS = 10000;
+#if BOARD_RX_INTERFACE != BOARD_RX_INTERFACE_ADC && \
+    BOARD_RX_INTERFACE != BOARD_RX_INTERFACE_DIGITAL
+#error "BOARD_RX_INTERFACE must select ADC or DIGITAL"
+#endif
+
+#if defined(MAKETKA) && BOARD_RX_INTERFACE == BOARD_RX_INTERFACE_ADC
+#error "MAKETKA requires BOARD_RX_INTERFACE_DIGITAL"
+#endif
+
+constexpr bool BOARD_RX_USES_ADC =
+  BOARD_RX_INTERFACE == BOARD_RX_INTERFACE_ADC;
+
+// Board-test parameters. These checks are selected at runtime from the UI;
+// no special diagnostic firmware build is required.
+constexpr uint32_t BOARD_PWM_TEST_FREQUENCY_HZ = 1;
+constexpr uint32_t BOARD_PWM_TEST_HALF_PERIOD_MS = 500;
 
 #if CONFIG_IDF_TARGET_ESP32C3
 constexpr bool TARGET_IS_C3 = true;
 constexpr uint8_t GPIO_PWM = 3;
 constexpr uint8_t GPIO_RX = 4;
 #ifdef MAKETKA
+constexpr bool BOARD_ADC_AVAILABLE = false;
 constexpr uint8_t GPIO_BUTTON_MODE = 0;
 constexpr uint8_t GPIO_BUTTON_START = 1;
+constexpr uint8_t GPIO_VBAT = UINT8_MAX;
+constexpr uint8_t GPIO_ANALOG_RX = UINT8_MAX;
 #else
+constexpr bool BOARD_ADC_AVAILABLE = true;
 constexpr uint8_t GPIO_BUTTON_MODE = 20;
 constexpr uint8_t GPIO_BUTTON_START = 10;
 constexpr uint8_t GPIO_VBAT = 2;
@@ -38,6 +52,7 @@ constexpr uint8_t GPIO_SCL = 7;
 #elif CONFIG_IDF_TARGET_ESP32S3
 constexpr bool TARGET_IS_C3 = false;
 #ifdef MAKETKA
+constexpr bool BOARD_ADC_AVAILABLE = false;
 // Same physical header contacts as the C3 MAKETKA profile when 5V/GND align.
 constexpr uint8_t GPIO_PWM = 12;
 constexpr uint8_t GPIO_RX = 13;
@@ -45,7 +60,10 @@ constexpr uint8_t GPIO_BUTTON_MODE = 9;
 constexpr uint8_t GPIO_BUTTON_START = 10;
 constexpr uint8_t GPIO_SDA = 44;
 constexpr uint8_t GPIO_SCL = 1;
+constexpr uint8_t GPIO_VBAT = UINT8_MAX;
+constexpr uint8_t GPIO_ANALOG_RX = UINT8_MAX;
 #else
+constexpr bool BOARD_ADC_AVAILABLE = true;
 // The S3 SuperMini is fitted so its 5V and GND pins occupy the same PCB
 // contacts as on the C3 SuperMini. Signals therefore follow header position.
 constexpr uint8_t GPIO_PWM = 12;
@@ -69,6 +87,8 @@ constexpr uint32_t SERIAL_BAUD = 115200;
 // Native USB CDC may keep a stale "connected" state after light sleep. Keep
 // logging non-blocking so a missing host can never delay button polling.
 constexpr uint32_t SERIAL_TX_TIMEOUT_MS = 2;
+constexpr uint32_t BOARD_ADC_PRINT_INTERVAL_MS = 100;
+constexpr uint32_t BOARD_TEST_DISPLAY_INTERVAL_MS = 250;
 constexpr bool SERIAL_ACTION_LOG = true;
 constexpr bool SERIAL_LOG_TIMESTAMPS = true;
 constexpr bool SERIAL_MINIMAL_LOG = true;
diff --git a/OpticalChannelTester/Config_Text.h b/OpticalChannelTester/Config_Text.h
index 1d06d5c..7bd5b15 100644
--- a/OpticalChannelTester/Config_Text.h
+++ b/OpticalChannelTester/Config_Text.h
@@ -21,6 +21,14 @@ constexpr const char *TEST_NAMES[] = {
   "ОПТИКА", "ДРАЙВЕР"
 };
 
+constexpr const char *TEST_GROUP_NAMES[] = {
+  "ОПТИКА", "ПЛАТА"
+};
+
+constexpr const char *BOARD_TEST_NAMES[] = {
+  "АЦП", "ШИМ ВЫХОД", "RX ВХОД"
+};
+
 constexpr const char *FAIL_NAMES[] = {
   "НЕТ ОШИБКИ",
   "НЕТ СИГНАЛА",
@@ -44,6 +52,7 @@ constexpr const char *MODE_PREFIX = "РЕЖИМ: ";
 constexpr const char *START_RUN = "ГОТОВ К ЗАПУСКУ";
 
 constexpr const char *MENU_FREQUENCY = "ЧАСТОТА ШИМ:";
+constexpr const char *MENU_TEST_GROUP = "ГРУППА ТЕСТОВ:";
 constexpr const char *MENU_MAX_PULSE = "МАКС. ИМПУЛЬС:";
 constexpr const char *MENU_MIN_PULSE = "МИН. ИМПУЛЬС:";
 constexpr const char *MENU_ACCURACY = "ТОЧНОСТЬ:";
@@ -53,6 +62,9 @@ constexpr const char *LIGHT_CODE_FORMAT = "TX:%c, RX:%c";
 constexpr const char *LIGHT_AUTO = "АВТО";
 constexpr const char *LIGHT_AUTO_FORMAT = "TX/RX: АВТО";
 constexpr const char *MENU_TOTAL_TIME = "ОБЩЕЕ ВРЕМЯ:";
+constexpr const char *BOARD_READY = "START: ЗАПУСК";
+constexpr const char *BOARD_STOP = "УДЕРЖ START: СТОП";
+constexpr const char *ADC_UNAVAILABLE = "АЦП НЕТ НА МАКЕТКЕ";
 constexpr const char *FREQUENCY_UNIT = " Гц";
 
 constexpr const char *SLAVE_READY = "СЛЕЙВ ГОТОВ";
@@ -87,6 +99,14 @@ constexpr const char *TEST_NAMES[] = {
   "OPTICAL", "DRIVER"
 };
 
+constexpr const char *TEST_GROUP_NAMES[] = {
+  "OPTICS", "BOARD"
+};
+
+constexpr const char *BOARD_TEST_NAMES[] = {
+  "ADC", "PWM OUTPUT", "RX INPUT"
+};
+
 constexpr const char *FAIL_NAMES[] = {
   "NONE",
   "NO SIGNAL",
@@ -110,6 +130,7 @@ constexpr const char *MODE_PREFIX = "MODE: ";
 constexpr const char *START_RUN = "READY TO START";
 
 constexpr const char *MENU_FREQUENCY = "PWM FREQUENCY:";
+constexpr const char *MENU_TEST_GROUP = "TEST GROUP:";
 constexpr const char *MENU_MAX_PULSE = "MAX PULSE:";
 constexpr const char *MENU_MIN_PULSE = "MIN PULSE:";
 constexpr const char *MENU_ACCURACY = "ACCURACY:";
@@ -119,6 +140,9 @@ constexpr const char *LIGHT_CODE_FORMAT = "TX:%c, RX:%c";
 constexpr const char *LIGHT_AUTO = "AUTO";
 constexpr const char *LIGHT_AUTO_FORMAT = "TX/RX: AUTO";
 constexpr const char *MENU_TOTAL_TIME = "TOTAL TIME:";
+constexpr const char *BOARD_READY = "START TO RUN";
+constexpr const char *BOARD_STOP = "HOLD START TO STOP";
+constexpr const char *ADC_UNAVAILABLE = "ADC ABSENT ON PROTOTYPE";
 constexpr const char *FREQUENCY_UNIT = " Hz";
 
 constexpr const char *SLAVE_READY = "SLAVE READY";
diff --git a/OpticalChannelTester/Core.cpp b/OpticalChannelTester/Core.cpp
index 90733d6..51534f7 100644
--- a/OpticalChannelTester/Core.cpp
+++ b/OpticalChannelTester/Core.cpp
@@ -9,12 +9,24 @@ const char *roleName(Role r) {
   return i < 3 ? names[i] : "?";
 }
 
+const char *testGroupName(TestGroup group) {
+  static const char *names[] = {"OPTICS", "BOARD"};
+  const uint8_t i = static_cast<uint8_t>(group);
+  return i < 2 ? names[i] : "?";
+}
+
 const char *testKindName(TestKind kind) {
   static const char *names[] = {"OPTICAL", "DRIVER"};
   const uint8_t i = static_cast<uint8_t>(kind);
   return i < 2 ? names[i] : "?";
 }
 
+const char *boardTestName(BoardTest test) {
+  static const char *names[] = {"ADC", "PWM OUTPUT", "RX INPUT"};
+  const uint8_t i = static_cast<uint8_t>(test);
+  return i < 3 ? names[i] : "?";
+}
+
 const char *lightCodeName(LightCode code) {
   static const char *names[] = {"HH", "HL", "LH", "LL"};
   const uint8_t i = static_cast<uint8_t>(code);
diff --git a/OpticalChannelTester/Core.h b/OpticalChannelTester/Core.h
index ec93ff2..d1d5017 100644
--- a/OpticalChannelTester/Core.h
+++ b/OpticalChannelTester/Core.h
@@ -4,7 +4,9 @@
 #include <stddef.h>
 
 enum class Role : uint8_t { SOLO, MASTER, SLAVE };
+enum class TestGroup : uint8_t { OPTICS, BOARD };
 enum class TestKind : uint8_t { OPTICAL, DRIVER };
+enum class BoardTest : uint8_t { ADC, PWM_OUTPUT, RX_INPUT };
 enum class LightCode : uint8_t { HH, HL, LH, LL };
 enum class FailReason : uint8_t {
   NONE, NO_SIGNAL, PERIOD_OUT, DUTY_OUT, EXTRA_EDGE, GLITCH, LOST_EDGE,
@@ -13,7 +15,9 @@ enum class FailReason : uint8_t {
 };
 
 const char *roleName(Role role);
+const char *testGroupName(TestGroup group);
 const char *testKindName(TestKind kind);
+const char *boardTestName(BoardTest test);
 const char *lightCodeName(LightCode code);
 const char *failName(FailReason reason);
 
@@ -27,7 +31,8 @@ struct Settings {
   uint8_t minPulseIndex;
   uint8_t accuracyIndex;
   uint8_t timeIndex;
-  uint16_t reserved;
+  uint8_t testGroup;
+  uint8_t boardTest;
   uint32_t checksum;
 };
 
diff --git a/OpticalChannelTester/OpticalChannelTester.ino b/OpticalChannelTester/OpticalChannelTester.ino
index 6fd658a..3518534 100644
--- a/OpticalChannelTester/OpticalChannelTester.ino
+++ b/OpticalChannelTester/OpticalChannelTester.ino
@@ -1,57 +1,6 @@
 #include "App.h"
-#include "Config.h"
-#include <math.h>
-
-#ifdef PWM_OUTPUT_TEST
-PwmGenerator pwmOutputTest;
-uint32_t pwmOutputTestPulseNs = PWM_OUTPUT_TEST_MIN_PULSE_NS;
-uint32_t pwmOutputTestUpdatedMs = 0;
-
-void setup() {
-  Serial.begin(SERIAL_BAUD);
-  delay(200);
-  Serial.printf("\nPWM OUTPUT TEST: GPIO=%u requested=%luHz pulse=%lu..%luns sine=%lums light-off=%s\n",
-    GPIO_PWM, PWM_OUTPUT_TEST_FREQUENCY_HZ,
-    PWM_OUTPUT_TEST_MIN_PULSE_NS, PWM_OUTPUT_TEST_MAX_PULSE_NS,
-    PWM_OUTPUT_TEST_SWEEP_PERIOD_MS,
-    TX_LIGHT_OFF_GPIO_LEVEL == HIGH ? "HIGH" : "LOW");
-
-  pwmOutputTest.begin();
-  ActualPwm actual = {};
-  if (pwmOutputTest.start(PWM_OUTPUT_TEST_FREQUENCY_HZ,
-                          pwmOutputTestPulseNs, actual)) {
-    Serial.printf("PWM OUTPUT TEST STARTED: actual=%luHz pulse=%luns bits=%u\n",
-      actual.actualHz, actual.actualPulseNs, actual.bits);
-  } else {
-    Serial.println("PWM OUTPUT TEST FAILED");
-  }
-}
-
-void loop() {
-  const uint32_t now = millis();
-  if (now - pwmOutputTestUpdatedMs < PWM_OUTPUT_TEST_UPDATE_MS) return;
-  pwmOutputTestUpdatedMs = now;
-
-  constexpr float PWM_TWO_PI = 6.28318530718f;
-  const float phase = PWM_TWO_PI * (now % PWM_OUTPUT_TEST_SWEEP_PERIOD_MS) /
-    PWM_OUTPUT_TEST_SWEEP_PERIOD_MS;
-  const float center = (PWM_OUTPUT_TEST_MIN_PULSE_NS + PWM_OUTPUT_TEST_MAX_PULSE_NS) * 0.5f;
-  const float amplitude = (PWM_OUTPUT_TEST_MAX_PULSE_NS - PWM_OUTPUT_TEST_MIN_PULSE_NS) * 0.5f;
-  const uint32_t pulseNs = static_cast<uint32_t>(center + amplitude * sinf(phase) + 0.5f);
-  if (pulseNs == pwmOutputTestPulseNs) return;
-
-  ActualPwm actual = {};
-  if (pwmOutputTest.start(PWM_OUTPUT_TEST_FREQUENCY_HZ, pulseNs, actual)) {
-    pwmOutputTestPulseNs = pulseNs;
-  } else {
-    Serial.printf("PWM OUTPUT TEST UPDATE FAILED: pulse=%luns\n", pulseNs);
-    delay(100);
-  }
-}
-#else
 App app;
 
 void setup() { app.begin(); }
 void loop() { app.update(); }
-#endif
 
diff --git a/OpticalChannelTester/SettingsStore.cpp b/OpticalChannelTester/SettingsStore.cpp
index 15b5e23..f4f8fe5 100644
--- a/OpticalChannelTester/SettingsStore.cpp
+++ b/OpticalChannelTester/SettingsStore.cpp
@@ -3,18 +3,23 @@
 #include "Log.h"
 #include <Preferences.h>
 
+// testGroup/boardTest reuse the former zeroed reserved bytes, so version 11
+// settings remain binary-compatible and keep the user's optical parameters.
 namespace { constexpr uint16_t SETTINGS_VERSION = 11; constexpr char NAMESPACE[] = "opt-test"; }
 
 void SettingsStore::defaults(Settings &s) const {
   // 2 kHz, 200 us .. 2 us, 5%, 1 s.
   s = {SETTINGS_VERSION, static_cast<uint8_t>(Role::SOLO),
     static_cast<uint8_t>(TestKind::OPTICAL), static_cast<uint8_t>(LightCode::HH),
-    2, 6, 3, 2, 3, 0, 0};
+    2, 6, 3, 2, 3, static_cast<uint8_t>(TestGroup::OPTICS),
+    static_cast<uint8_t>(BoardTest::ADC), 0};
   s.checksum = settingsChecksum(s);
 }
 
 bool SettingsStore::valid(const Settings &s) const {
   return s.version == SETTINGS_VERSION && s.role <= static_cast<uint8_t>(Role::SLAVE) &&
+    s.testGroup <= static_cast<uint8_t>(TestGroup::BOARD) &&
+    s.boardTest <= static_cast<uint8_t>(BoardTest::RX_INPUT) &&
     s.testKind <= static_cast<uint8_t>(TestKind::DRIVER) &&
     s.lightCode <= static_cast<uint8_t>(LightCode::LL) &&
     (s.testKind != static_cast<uint8_t>(TestKind::DRIVER) ||
diff --git a/README.md b/README.md
index 920292d..baaf0d9 100644
--- a/README.md
+++ b/README.md
@@ -160,13 +160,47 @@ MASTER <~~~~ ESP-NOW Wi-Fi channel 6 ~~~~> SLAVE
 
 ## Управление
 
-В ожидании на S3:
+В ожидании в группе `ОПТИКА` на S3:
 
 - MODE short: `SOLO ОПТИКА → SOLO ДРАЙВЕР → MASTER ОПТИКА → SLAVE ОПТИКА`;
 - MODE long: открыть настройки;
 - START short: начать тест;
 - START long во время теста: ABORT, PWM немедленно выключается.
 
+В ожидании в группе `ПЛАТА`:
+
+- MODE short для аналоговой платы: `АЦП ↔ ШИМ ВЫХОД`;
+- MODE short для цифровой платы: `RX ВХОД ↔ ШИМ ВЫХОД`;
+- MODE long: открыть настройки;
+- START short: запустить выбранный тест платы;
+- START long: остановить тест платы и вернуться к выбору.
+
+При запуске `АЦП` или `RX ВХОД` оптический передатчик постоянно включается
+уровнем `TX_LIGHT_ON_GPIO_LEVEL`. При остановке теста свет выключается. В
+`ШИМ ВЫХОД` этот же вывод переключается с частотой 1 Гц и заполнением 50%:
+500 мс свет включён, 500 мс выключен, поэтому работу выхода видно глазом.
+
+`АЦП` каждые 100 мс выводит в Serial текущие сырые значения входов
+`GPIO_ANALOG_RX` и `GPIO_VBAT`, а также периодически обновляет OLED. Этот тест
+доступен в профиле производственной PCB; в профиле `MAKETKA` прошивка явно
+сообщает об отсутствии этих входов. `ШИМ ВЫХОД` заменяет прежний
+`PWM_OUTPUT_TEST`, а `RX ВХОД` — прежний `RX_PIN_CHANGE_TEST`; отдельная сборка
+диагностической прошивки больше не нужна.
+
+Тип распаянного приёмника выбирается в `Config.h` одним взаимоисключающим
+значением:
+
+```cpp
+#define BOARD_RX_INTERFACE BOARD_RX_INTERFACE_ADC
+// или
+#define BOARD_RX_INTERFACE BOARD_RX_INTERFACE_DIGITAL
+```
+
+По умолчанию выбрана плата с АЦП. Одновременно аналоговый и цифровой тесты
+приёмника в меню не появляются. Для `MAKETKA` следует выбрать
+`BOARD_RX_INTERFACE_DIGITAL`, поскольку аналоговые выводы в этом профиле
+отсутствуют.
+
 В настройках:
 
 - MODE short: следующий параметр;
@@ -184,7 +218,11 @@ START и MODE будят устройство. Первое, пробуждаю
 
 ## Настройки теста
 
-Меню содержит шесть общих параметров:
+Первый пункт меню выбирает группу `ОПТИКА` или `ПЛАТА`. Для группы `ПЛАТА`
+это единственная настройка: конкретный аппаратный тест выбирается коротким
+нажатием MODE в экране ожидания.
+
+Для группы `ОПТИКА` меню дополнительно содержит шесть параметров:
 
 1. частота ШИМ из `PWM_FREQUENCY_OPTIONS_HZ`;
 2. максимальная длительность импульса из отдельного `MAX_PULSE_OPTIONS_NS`;