Test an accessible OLED menu

Change contrast, text size, sound, and brightness in an ESP32 menu and compare each stored setting with its visible or audible effect.

UX Uma: I want you to test what each preference actually changes and record where the visible result falls short of its label., your practice guide

UX Uma: I want you to test what each preference actually changes and record where the visible result falls short of its label.
Predict the reading, then compare it with the measurement.

Wokwi ESP32

Third party Tool

Change contrast, text size, sound, and brightness in an ESP32 menu and compare each stored setting with its visible or audible effect.

Tier 1 · Web · No account

Version tested: Compiled and booted by the Wokwi gate (ESP32 Arduino core 3.3.11); captured in the Wokwi web editor on 2026-09-09. Date: 2026-09-09.

Open the ESP32 editor, paste diagram.json, then paste sketch.ino.

Open Wokwi to paste in the files (new tab)

Get the files

Use both prepared files. This is a paste-in setup; saving a project requires a Wokwi account.

diagram.json

2,829 bytes · Circuit connections

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{
  "version": 1,
  "author": "IoT Class",
  "editor": "wokwi",
  "parts": [
    {
      "type": "wokwi-esp32-devkit-v1",
      "id": "esp",
      "top": 0,
      "left": 0,
      "attrs": {}
    },
    {
      "type": "wokwi-ssd1306",
      "id": "oled1",
      "top": -100,
      "left": 150,
      "attrs": {
        "i2cAddress": "0x3c"
      }
    },
    {
      "type": "wokwi-pushbutton",
      "id": "btn1",
      "top": 100,
      "left": 200,
      "attrs": {
        "color": "green",
        "label": "UP"
      }
    },
    {
      "type": "wokwi-pushbutton",
      "id": "btn2",
      "top": 140,
      "left": 200,
      "attrs": {
        "color": "blue",
        "label": "DOWN"
      }
    },
    {
      "type": "wokwi-pushbutton",
      "id": "btn3",
      "top": 180,
      "left": 200,
      "attrs": {
        "color": "red",
        "label": "SELECT"
      }
    },
    {
      "type": "wokwi-pushbutton",
      "id": "btn4",
      "top": 220,
      "left": 200,
      "attrs": {
        "color": "yellow",
        "label": "BACK"
      }
    },
    {
      "type": "wokwi-buzzer",
      "id": "bz1",
      "top": 100,
      "left": -80,
      "attrs": {}
    }
  ],
  "connections": [
    [
      "esp:TX0",
      "$serialMonitor:RX",
      "",
      []
    ],
    [
      "esp:RX0",
      "$serialMonitor:TX",
      "",
      []
    ],
    [
      "oled1:GND",
      "esp:GND.1",
      "black",
      [
        "v-20",
        "h-60"
      ]
    ],
    [
      "oled1:VCC",
      "esp:3V3",
      "red",
      [
        "v-30",
        "h-80"
      ]
    ],
    [
      "oled1:SDA",
      "esp:D21",
      "green",
      [
        "v-40",
        "h-100"
      ]
    ],
    [
      "oled1:SCL",
      "esp:D22",
      "blue",
      [
        "v-50",
        "h-120"
      ]
    ],
    [
      "btn1:1.l",
      "esp:D25",
      "green",
      [
        "h-50"
      ]
    ],
    [
      "btn1:2.l",
      "esp:GND.1",
      "black",
      [
        "h-30",
        "v50"
      ]
    ],
    [
      "btn2:1.l",
      "esp:D26",
      "blue",
      [
        "h-60"
      ]
    ],
    [
      "btn2:2.l",
      "esp:GND.1",
      "black",
      [
        "h-40",
        "v30"
      ]
    ],
    [
      "btn3:1.l",
      "esp:D27",
      "red",
      [
        "h-70"
      ]
    ],
    [
      "btn3:2.l",
      "esp:GND.1",
      "black",
      [
        "h-50",
        "v10"
      ]
    ],
    [
      "btn4:1.l",
      "esp:D14",
      "yellow",
      [
        "h-80"
      ]
    ],
    [
      "btn4:2.l",
      "esp:GND.1",
      "black",
      [
        "h-60",
        "v-10"
      ]
    ],
    [
      "bz1:2",
      "esp:D13",
      "orange",
      [
        "h30"
      ]
    ],
    [
      "bz1:1",
      "esp:GND.1",
      "black",
      [
        "h20",
        "v30"
      ]
    ]
  ]
}

sketch.ino

15,728 bytes · ESP32 program

Download

/*
 * Accessible IoT Interface Lab
 *
 * Demonstrates core UI/UX accessibility principles:
 * - Multimodal feedback (visual, audio, timing)
 * - High contrast mode for visual impairments
 * - Large text mode for readability
 * - Audio confirmation sounds
 * - Persistent user preferences (NVS)
 * - Debounced button input
 *
 * Compatible with: ESP32 DevKit, Wokwi Simulator
 * Display: SSD1306 OLED 128x64 (I2C)
 */

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Preferences.h>

// ========== DISPLAY CONFIGURATION ==========
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
#define SCREEN_ADDRESS 0x3C

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// ========== PIN DEFINITIONS ==========
#define BTN_UP 25
#define BTN_DOWN 26
#define BTN_SELECT 27
#define BTN_BACK 14
#define BUZZER_PIN 13
#define LED_PIN 2

// ========== TIMING CONSTANTS ==========
#define DEBOUNCE_DELAY 200
#define MENU_ANIMATION_DELAY 50
#define FEEDBACK_DURATION 100

// ========== AUDIO FEEDBACK FREQUENCIES ==========
#define TONE_NAVIGATE 800    // Navigation beep
#define TONE_SELECT 1200     // Selection confirmation
#define TONE_BACK 400        // Back/cancel tone
#define TONE_ERROR 200       // Error tone
#define TONE_SUCCESS 1600    // Success confirmation
#define TONE_TOGGLE_ON 1000  // Toggle enabled
#define TONE_TOGGLE_OFF 600  // Toggle disabled

// ========== USER PREFERENCES ==========
Preferences preferences;

struct AccessibilitySettings {
  bool highContrast;
  bool largeText;
  bool soundEnabled;
  uint8_t brightness;
} settings;

// ========== MENU SYSTEM ==========
enum MenuState {
  MENU_HOME,
  MENU_MAIN,
  MENU_SETTINGS,
  MENU_ACCESSIBILITY,
  MENU_SYSTEM_INFO
};

MenuState currentMenu = MENU_HOME;
int menuIndex = 0;
int maxMenuItems = 3;

// Menu item labels
const char* mainMenuItems[] = {"Home", "Settings", "System Info"};
const char* accessibilityItems[] = {"High Contrast", "Large Text", "Sound", "Brightness", "Back"};

// ========== DEBOUNCING ==========
unsigned long lastButtonPress = 0;

// ========== FUNCTION DECLARATIONS ==========
void loadSettings();
void saveSettings();
void playTone(int frequency, int duration);
void playNavigateSound();
void playSelectSound();
void playBackSound();
void playToggleSound(bool enabled);
void drawMenu();
void drawHome();
void drawMainMenu();
void drawAccessibilityMenu();
void drawSystemInfo();
void handleNavigation(int direction);
void handleSelect();
void handleBack();
void updateDisplay();
void showFeedback(const char* message, bool success);
void blinkLED(int times);

// ========== SETUP ==========
void setup() {
  Serial.begin(115200);
  Serial.println("\n=== Accessible IoT Interface Lab ===");
  Serial.println("Demonstrating UI/UX accessibility principles");

// Initialize pins
  pinMode(BTN_UP, INPUT_PULLUP);
  pinMode(BTN_DOWN, INPUT_PULLUP);
  pinMode(BTN_SELECT, INPUT_PULLUP);
  pinMode(BTN_BACK, INPUT_PULLUP);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);

// Initialize display
  Wire.begin(21, 22);
  if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println("ERROR: SSD1306 allocation failed");
    for (;;); // Halt if display fails
  }

display.clearDisplay();
  display.setTextColor(SSD1306_WHITE);
  display.display();

// Load saved preferences
  loadSettings();

// Apply brightness setting
  display.dim(settings.brightness < 50);

// Welcome feedback
  Serial.println("Settings loaded:");
  Serial.printf("  High Contrast: %s\n", settings.highContrast ? "ON" : "OFF");
  Serial.printf("  Large Text: %s\n", settings.largeText ? "ON" : "OFF");
  Serial.printf("  Sound: %s\n", settings.soundEnabled ? "ON" : "OFF");
  Serial.printf("  Brightness: %d%%\n", settings.brightness);

// Startup sound and visual
  if (settings.soundEnabled) {
    playTone(TONE_SUCCESS, 100);
    delay(50);
    playTone(TONE_SUCCESS + 200, 100);
  }
  blinkLED(2);

// Show home screen
  drawHome();
}

// ========== MAIN LOOP ==========
void loop() {
  // Check for button presses with debouncing
  if (millis() - lastButtonPress > DEBOUNCE_DELAY) {

// UP button
    if (digitalRead(BTN_UP) == LOW) {
      lastButtonPress = millis();
      handleNavigation(-1);
      Serial.println("BTN: UP pressed");
    }

// DOWN button
    else if (digitalRead(BTN_DOWN) == LOW) {
      lastButtonPress = millis();
      handleNavigation(1);
      Serial.println("BTN: DOWN pressed");
    }

// SELECT button
    else if (digitalRead(BTN_SELECT) == LOW) {
      lastButtonPress = millis();
      handleSelect();
      Serial.println("BTN: SELECT pressed");
    }

// BACK button
    else if (digitalRead(BTN_BACK) == LOW) {
      lastButtonPress = millis();
      handleBack();
      Serial.println("BTN: BACK pressed");
    }
  }

delay(10); // Small delay for stability
}

// ========== SETTINGS MANAGEMENT ==========
void loadSettings() {
  preferences.begin("access", false);
  settings.highContrast = preferences.getBool("contrast", false);
  settings.largeText = preferences.getBool("largetext", false);
  settings.soundEnabled = preferences.getBool("sound", true);
  settings.brightness = preferences.getUChar("brightness", 100);
  preferences.end();
}

void saveSettings() {
  preferences.begin("access", false);
  preferences.putBool("contrast", settings.highContrast);
  preferences.putBool("largetext", settings.largeText);
  preferences.putBool("sound", settings.soundEnabled);
  preferences.putUChar("brightness", settings.brightness);
  preferences.end();
  Serial.println("Settings saved to NVS");
}

// ========== AUDIO FEEDBACK ==========
void playTone(int frequency, int duration) {
  if (!settings.soundEnabled) return;
  tone(BUZZER_PIN, frequency, duration);
  delay(duration);
  noTone(BUZZER_PIN);
}

void playNavigateSound() {
  playTone(TONE_NAVIGATE, 30);
}

void playSelectSound() {
  playTone(TONE_SELECT, 50);
  delay(30);
  playTone(TONE_SELECT + 200, 50);
}

void playBackSound() {
  playTone(TONE_BACK, 80);
}

void playToggleSound(bool enabled) {
  if (enabled) {
    playTone(TONE_TOGGLE_ON, 50);
    delay(30);
    playTone(TONE_TOGGLE_ON + 400, 80);
  } else {
    playTone(TONE_TOGGLE_OFF + 200, 50);
    delay(30);
    playTone(TONE_TOGGLE_OFF, 80);
  }
}

void playErrorSound() {
  playTone(TONE_ERROR, 100);
  delay(50);
  playTone(TONE_ERROR, 100);
}

// ========== VISUAL FEEDBACK ==========
void blinkLED(int times) {
  for (int i = 0; i < times; i++) {
    digitalWrite(LED_PIN, HIGH);
    delay(100);
    digitalWrite(LED_PIN, LOW);
    delay(100);
  }
}

void showFeedback(const char* message, bool success) {
  // Visual feedback on display
  display.fillRect(0, 54, 128, 10, settings.highContrast ? SSD1306_WHITE : SSD1306_BLACK);
  display.setTextColor(settings.highContrast ? SSD1306_BLACK : SSD1306_WHITE);
  display.setTextSize(1);
  display.setCursor(4, 55);
  display.print(message);
  display.display();

// Audio feedback
  if (success) {
    playTone(TONE_SUCCESS, 100);
  } else {
    playErrorSound();
  }

// LED feedback
  blinkLED(success ? 1 : 3);

delay(500);
  updateDisplay();
}

// ========== NAVIGATION HANDLING ==========
void handleNavigation(int direction) {
  menuIndex += direction;

// Wrap around menu
  if (menuIndex < 0) menuIndex = maxMenuItems - 1;
  if (menuIndex >= maxMenuItems) menuIndex = 0;

playNavigateSound();
  blinkLED(1);
  updateDisplay();
}

void handleSelect() {
  playSelectSound();
  blinkLED(1);

switch (currentMenu) {
    case MENU_HOME:
      currentMenu = MENU_MAIN;
      menuIndex = 0;
      maxMenuItems = 3;
      break;

case MENU_MAIN:
      switch (menuIndex) {
        case 0: // Home
          currentMenu = MENU_HOME;
          break;
        case 1: // Settings -> Accessibility
          currentMenu = MENU_ACCESSIBILITY;
          menuIndex = 0;
          maxMenuItems = 5;
          break;
        case 2: // System Info
          currentMenu = MENU_SYSTEM_INFO;
          break;
      }
      break;

case MENU_ACCESSIBILITY:
      switch (menuIndex) {
        case 0: // Toggle High Contrast
          settings.highContrast = !settings.highContrast;
          playToggleSound(settings.highContrast);
          saveSettings();
          Serial.printf("High Contrast: %s\n", settings.highContrast ? "ON" : "OFF");
          break;
        case 1: // Toggle Large Text
          settings.largeText = !settings.largeText;
          playToggleSound(settings.largeText);
          saveSettings();
          Serial.printf("Large Text: %s\n", settings.largeText ? "ON" : "OFF");
          break;
        case 2: // Toggle Sound
          settings.soundEnabled = !settings.soundEnabled;
          // Play sound BEFORE disabling
          if (!settings.soundEnabled) {
            tone(BUZZER_PIN, TONE_TOGGLE_OFF + 200, 50);
            delay(30);
            tone(BUZZER_PIN, TONE_TOGGLE_OFF, 80);
            noTone(BUZZER_PIN);
          } else {
            playToggleSound(true);
          }
          saveSettings();
          Serial.printf("Sound: %s\n", settings.soundEnabled ? "ON" : "OFF");
          break;
        case 3: // Adjust Brightness
          settings.brightness += 25;
          if (settings.brightness > 100) settings.brightness = 25;
          display.dim(settings.brightness < 50);
          playTone(800 + (settings.brightness * 8), 50);
          saveSettings();
          Serial.printf("Brightness: %d%%\n", settings.brightness);
          break;
        case 4: // Back
          handleBack();
          return;
      }
      break;

case MENU_SYSTEM_INFO:
      // Return to main menu
      handleBack();
      return;
  }

updateDisplay();
}

void handleBack() {
  playBackSound();
  blinkLED(1);

switch (currentMenu) {
    case MENU_HOME:
      // Already at home, do nothing
      break;
    case MENU_MAIN:
      currentMenu = MENU_HOME;
      break;
    case MENU_ACCESSIBILITY:
    case MENU_SYSTEM_INFO:
      currentMenu = MENU_MAIN;
      menuIndex = 0;
      maxMenuItems = 3;
      break;
  }

updateDisplay();
}

// ========== DISPLAY RENDERING ==========
void updateDisplay() {
  switch (currentMenu) {
    case MENU_HOME:
      drawHome();
      break;
    case MENU_MAIN:
      drawMainMenu();
      break;
    case MENU_ACCESSIBILITY:
      drawAccessibilityMenu();
      break;
    case MENU_SYSTEM_INFO:
      drawSystemInfo();
      break;
  }
}

void drawHome() {
  display.clearDisplay();

// Background for high contrast mode
  if (settings.highContrast) {
    display.fillScreen(SSD1306_WHITE);
    display.setTextColor(SSD1306_BLACK);
  } else {
    display.setTextColor(SSD1306_WHITE);
  }

// Title
  display.setTextSize(settings.largeText ? 2 : 1);
  display.setCursor(settings.largeText ? 10 : 25, 4);
  display.print("IoT Device");

// Status indicator with icon
  display.setTextSize(1);
  display.setCursor(4, settings.largeText ? 28 : 20);
  display.print("Status: ");
  display.print("ONLINE");

// Draw status indicator circle
  int circleX = settings.largeText ? 100 : 75;
  int circleY = settings.largeText ? 32 : 23;
  if (settings.highContrast) {
    display.fillCircle(circleX, circleY, 4, SSD1306_BLACK);
  } else {
    display.fillCircle(circleX, circleY, 4, SSD1306_WHITE);
  }

// Show active accessibility features
  display.setCursor(4, settings.largeText ? 44 : 36);
  if (settings.highContrast || settings.largeText) {
    display.print("A11y: ");
    if (settings.highContrast) display.print("HC ");
    if (settings.largeText) display.print("LT ");
  }

// Navigation hint
  display.setCursor(4, 54);
  display.setTextSize(1);
  display.print("[SELECT] Open Menu");

display.display();
}

void drawMainMenu() {
  display.clearDisplay();

if (settings.highContrast) {
    display.fillScreen(SSD1306_WHITE);
    display.setTextColor(SSD1306_BLACK);
  } else {
    display.setTextColor(SSD1306_WHITE);
  }

// Title
  display.setTextSize(settings.largeText ? 2 : 1);
  display.setCursor(settings.largeText ? 20 : 40, 2);
  display.print("MENU");

// Draw menu items
  display.setTextSize(settings.largeText ? 2 : 1);
  int yStart = settings.largeText ? 22 : 18;
  int ySpacing = settings.largeText ? 14 : 12;

for (int i = 0; i < 3; i++) {
    int y = yStart + (i * ySpacing);

// Highlight selected item
    if (i == menuIndex) {
      if (settings.highContrast) {
        display.fillRect(0, y - 2, 128, ySpacing, SSD1306_BLACK);
        display.setTextColor(SSD1306_WHITE);
      } else {
        display.fillRect(0, y - 2, 128, ySpacing, SSD1306_WHITE);
        display.setTextColor(SSD1306_BLACK);
      }
      display.setCursor(4, y);
      display.print("> ");
    } else {
      display.setTextColor(settings.highContrast ? SSD1306_BLACK : SSD1306_WHITE);
      display.setCursor(4, y);
      display.print("  ");
    }
    display.print(mainMenuItems[i]);
  }

// Navigation hints
  display.setTextSize(1);
  display.setTextColor(settings.highContrast ? SSD1306_BLACK : SSD1306_WHITE);
  display.setCursor(4, 54);
  display.print("[UP/DN] Nav [SEL] OK");

display.display();
}

void drawAccessibilityMenu() {
  display.clearDisplay();

if (settings.highContrast) {
    display.fillScreen(SSD1306_WHITE);
    display.setTextColor(SSD1306_BLACK);
  } else {
    display.setTextColor(SSD1306_WHITE);
  }

// Title
  display.setTextSize(1);
  display.setCursor(20, 2);
  display.print("ACCESSIBILITY");

// Draw menu items with current values
  int yStart = 14;
  int ySpacing = 10;

for (int i = 0; i < 5; i++) {
    int y = yStart + (i * ySpacing);

// Highlight selected item
    if (i == menuIndex) {
      if (settings.highContrast) {
        display.fillRect(0, y - 1, 128, ySpacing, SSD1306_BLACK);
        display.setTextColor(SSD1306_WHITE);
      } else {
        display.fillRect(0, y - 1, 128, ySpacing, SSD1306_WHITE);
        display.setTextColor(SSD1306_BLACK);
      }
    } else {
      display.setTextColor(settings.highContrast ? SSD1306_BLACK : SSD1306_WHITE);
    }

display.setCursor(4, y);
    if (i == menuIndex) display.print(">");
    display.setCursor(12, y);
    display.print(accessibilityItems[i]);

// Show current values
    display.setCursor(90, y);
    switch (i) {
      case 0: display.print(settings.highContrast ? "[ON]" : "[OFF]"); break;
      case 1: display.print(settings.largeText ? "[ON]" : "[OFF]"); break;
      case 2: display.print(settings.soundEnabled ? "[ON]" : "[OFF]"); break;
      case 3:
        display.print("[");
        display.print(settings.brightness);
        display.print("%]");
        break;
      case 4: display.print(""); break;
    }
  }

// Navigation hints
  display.setTextColor(settings.highContrast ? SSD1306_BLACK : SSD1306_WHITE);
  display.setCursor(4, 54);
  display.print("[SEL] Toggle [BACK]");

display.display();
}

void drawSystemInfo() {
  display.clearDisplay();

if (settings.highContrast) {
    display.fillScreen(SSD1306_WHITE);
    display.setTextColor(SSD1306_BLACK);
  } else {
    display.setTextColor(SSD1306_WHITE);
  }

// Title
  display.setTextSize(1);
  display.setCursor(25, 2);
  display.print("SYSTEM INFO");

// System information
  display.setCursor(4, 16);
  display.print("Device: ESP32");

display.setCursor(4, 26);
  display.print("Uptime: ");
  display.print(millis() / 1000);
  display.print("s");

display.setCursor(4, 36);
  display.print("Free Heap: ");
  display.print(ESP.getFreeHeap() / 1024);
  display.print("KB");

display.setCursor(4, 46);
  display.print("Display: 128x64 OLED");

// Navigation hint
  display.setCursor(4, 54);
  display.print("[BACK] Return");

display.display();
}

Use the launch button above to open the ESP32 editor in Wokwi.
Select the editor’s diagram.json tab and replace all its text with the supplied diagram.json.
Select the sketch.ino tab, replace all its text with the supplied sketch.ino, then click Start Simulation.

Steps

Screens captured against Wokwi ESP32 Compiled and booted by the Wokwi gate (ESP32 Arduino core 3.3.11); captured in the Wokwi web editor on 2026-09-09 on 2026-09-09; the tool may have moved on — the text steps are the contract.

Step 1
Do
Paste the diagram and sketch into Wokwi ESP32. Install Adafruit GFX Library and Adafruit SSD1306. Inspect the OLED and button wiring.
You will see
The OLED uses address 0x3C on GPIO 21/22; four active-low buttons use GPIO 25/26/27/14 and the buzzer uses GPIO 13.
Why it matters
A usable interface depends on consistent input and feedback paths, as well as its visual arrangement.
Step 2
Do
Start at 115200 baud, read the startup settings, and tap SELECT to open the main menu.
You will see
Fresh settings are High Contrast OFF, Large Text OFF, Sound ON, Brightness 100%. Main menu entries are Home, Settings, and System Info.
Why it matters
Explicit initial state makes later changes testable. Saved NVS preferences may produce different startup values.
Step 3
Do
Tap DOWN once to Settings and SELECT. With High Contrast selected, tap SELECT again.
You will see
Serial prints Settings saved to NVS and High Contrast: ON from a fresh baseline; the display reverses its light and dark areas.
Why it matters
The host prioritizes important status that users can find and interpret. A contrast preference should have an observable display effect.
Step 4
Do
Tap DOWN to Large Text and SELECT, then use BACK to inspect the main menu.
You will see
Serial reports Large Text: ON and the main menu uses larger text. The accessibility settings list itself remains small and can look crowded.
Why it matters
Test every relevant screen rather than accepting a preference flag as proof of readable layout.
Step 5
Do
Return to Settings, navigate to Sound, and toggle it OFF; then navigate once.
You will see
Serial reports Sound: OFF; subsequent navigation is silent while the display and status LED still provide feedback.
Why it matters
The host’s alert-fatigue principle applies to feedback too: sound should be controllable without removing all indication of state.
Step 6
Do
Select Brightness repeatedly and compare the printed values with the display.
You will see
Starting at 100%, values cycle through 25%, 50%, 75%, and 100%. Only 25% uses the dim mode; the source does not implement four proportional intensity levels.
Why it matters
A numeric label can imply more precision than the device implements. Compare the setting’s meaning with actual behavior.
Step 7
Do
Restore High Contrast OFF, Large Text OFF, Sound ON, and Brightness 100%; return to the home screen.
You will see
Serial confirms each restored value and NVS saves. The home screen returns to its small-text baseline with navigation sound enabled.
Why it matters
Restoring a known baseline makes the next usability comparison repeatable. Persistent preference writes alone do not establish cross-session simulator storage behavior.

Chapter checks

These questions refer to the chapter’s examples. Use the return links to review their answers.

You're designing a dashboard for a factory floor monitoring system. The operator needs to see: (1) machine status (running/stopped/error), (2) production count, (3) temperature readings, and (4) 7-day production trends. Where should you place the machine status indicator?
Return to the chapter’s knowledge check
A smart building dashboard monitors HVAC systems. Temperature thresholds are set to: Normal (18-24 C), Warning (15-18 or 24-28 C), Critical (<15 or >28 C). During testing, operators complain about 'alert fatigue' - too many warnings. Analysis shows 85% of warnings occur briefly during HVAC startup. What's the BEST solution?
Return to the chapter’s knowledge check

Return to Interface Design: Dashboards · Browse Labs

Wokwi ESP32

Get the files

diagram.json

sketch.ino

Steps

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Chapter checks

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