diff --git a/examples/pin_test/pin_test.ino b/examples/pin_test/pin_test.ino
new file mode 100644
index 0000000..d625842
--- /dev/null
+++ b/examples/pin_test/pin_test.ino
@@ -0,0 +1,342 @@
+/*
+ * SPDX-FileCopyrightText: 2026 M5Stack Technology CO LTD
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+/*
+ * M5IOE1 引脚测试示例
+ * M5IOE1 Pin Test Example
+ *
+ * 本示例展示 M5IOE1 库的核心功能
+ * This example demonstrates the core features of M5IOE1 library
+ *
+ * 硬件连接 / Hardware Connections:
+ * - M5IOE1 SDA -> GPIO 38, SCL -> GPIO 39
+ * - IO1 -> 按钮 (Button, active LOW to GND)
+ * - IO3 -> LED (through 220Ω to GND)
+ * - IO2 -> 电位器 / Potentiometer (ADC Channel 1, 0-3.3V)
+ * - IO9 -> LED (PWM Channel 0, through 220Ω to GND)
+ */
+
+#include <M5IOE1.h>
+
+// ============================
+// 配置 / Configuration
+// ============================
+#define I2C_SDA_PIN 38
+#define I2C_SCL_PIN 39
+#define I2C_FREQ 400000
+#define I2C_ADDR M5IOE1_DEFAULT_ADDR
+
+// ============================
+// 引脚定义 / Pin Definitions
+// ============================
+// IO1 (Pin 0) - 数字输入，按钮 / Digital input, button
+#define PIN_BUTTON M5IOE1_PIN_1  // IO1
+// IO3 (Pin 2) - 数字输出，LED / Digital output, LED
+#define PIN_LED M5IOE1_PIN_3     // IO3
+// IO2 (Pin 1) - ADC 输入，电位器 / ADC input, potentiometer (ADC Channel 1)
+#define PIN_ADC M5IOE1_PIN_2     // IO2 -> ADC_CH1
+// IO9 (Pin 8) - PWM 输出，LED / PWM output, LED (PWM Channel 0)
+#define PIN_PWM M5IOE1_PIN_9     // IO9 -> PWM_CH1
+
+// ============================
+// 全局变量 / Global Variables
+// ============================
+M5IOE1 ioe1;
+
+volatile int buttonPressCount = 0;
+uint8_t pwmValue = 0;
+int pwmDirection = 1;
+
+// ============================
+// 中断回调函数 / Interrupt Callback
+// ============================
+void IRAM_ATTR buttonPressed() {
+    buttonPressCount++;
+}
+
+// ============================
+// 辅助函数 / Helper Functions
+// ============================
+void printSeparator(const char* title) {
+    Serial.println("\n========================================");
+    Serial.println(title);
+    Serial.println("========================================\n");
+}
+
+void testDigitalWrite() {
+    printSeparator("测试 digitalWrite() / Testing digitalWrite()");
+
+    Serial.println("Blinking LED on IO3 (3 cycles)...\n");
+
+    for (int i = 0; i < 3; i++) {
+        Serial.print("Cycle ");
+        Serial.print(i + 1);
+        Serial.println(": HIGH -> LOW");
+        ioe1.digitalWrite(PIN_LED, HIGH);
+        delay(500);
+        ioe1.digitalWrite(PIN_LED, LOW);
+        delay(500);
+    }
+
+    Serial.println("digitalWrite() test completed!\n");
+}
+
+void testDigitalRead() {
+    printSeparator("测试 digitalRead() / Testing digitalRead()");
+
+    Serial.println("Reading button on IO1 (active LOW) for 8 seconds...");
+    Serial.println("Press the button to test!\n");
+
+    unsigned long startTime = millis();
+    int lastState = -1;
+
+    while (millis() - startTime < 8000) {
+        int currentState = ioe1.digitalRead(PIN_BUTTON);
+
+        if (currentState != lastState) {
+            Serial.print("State: ");
+            Serial.println(currentState == LOW ? "LOW (pressed)" : "HIGH (released)");
+            lastState = currentState;
+        }
+        delay(50);
+    }
+
+    Serial.println("\ndigitalRead() test completed!\n");
+}
+
+void testPinMode() {
+    printSeparator("测试 pinMode() / Testing pinMode()");
+
+    Serial.println("Testing pin modes on IO3:\n");
+
+    // OUTPUT + 闪烁测试 / OUTPUT + Blink test
+    Serial.println("1. OUTPUT mode");
+    ioe1.pinMode(PIN_LED, OUTPUT);
+    for (int i = 0; i < 2; i++) {
+        ioe1.digitalWrite(PIN_LED, HIGH);
+        delay(200);
+        ioe1.digitalWrite(PIN_LED, LOW);
+        delay(200);
+    }
+    Serial.println("   -> Blink test OK\n");
+
+    // INPUT + 读取测试 / INPUT + Read test
+    Serial.println("2. INPUT mode (floating)");
+    ioe1.pinMode(PIN_LED, INPUT);
+    int val = ioe1.digitalRead(PIN_LED);
+    Serial.print("   -> Read: ");
+    Serial.println(val == HIGH ? "HIGH" : "LOW");
+    Serial.println("   -> OK\n");
+
+    // INPUT_PULLUP + 读取测试 / INPUT_PULLUP + Read test
+    Serial.println("3. INPUT_PULLUP mode");
+    ioe1.pinMode(PIN_LED, INPUT_PULLUP);
+    val = ioe1.digitalRead(PIN_LED);
+    Serial.print("   -> Read: ");
+    Serial.println(val == HIGH ? "HIGH (pulled up)" : "LOW");
+    Serial.println("   -> OK\n");
+
+    // 恢复输出模式 / Restore OUTPUT mode
+    ioe1.pinMode(PIN_LED, OUTPUT);
+
+    Serial.println("pinMode() test completed!\n");
+}
+
+void testAnalogRead() {
+    printSeparator("测试 analogRead() / Testing analogRead()");
+
+    Serial.println("Reading ADC Channel 1 (IO2) for 8 seconds...");
+    Serial.println("Rotate potentiometer to test!\n");
+
+    unsigned long startTime = millis();
+    unsigned long lastPrint = 0;
+
+    while (millis() - startTime < 8000) {
+        uint16_t adcValue;
+
+        if (ioe1.analogRead(1, &adcValue)) {
+            if (millis() - lastPrint > 500) {
+                float voltage = (adcValue * 3300.0f) / 4095.0f;
+
+                Serial.print("Value: ");
+                Serial.print(adcValue);
+                Serial.print(" (");
+                Serial.print((int)voltage);
+                Serial.println(" mV)");
+
+                // 简单的条形图 / Simple bar graph
+                int bars = map(adcValue, 0, 4095, 0, 20);
+                Serial.print("[");
+                for (int i = 0; i < 20; i++) {
+                    Serial.print(i < bars ? "=" : " ");
+                }
+                Serial.println("]\n");
+
+                lastPrint = millis();
+            }
+        }
+        delay(50);
+    }
+
+    Serial.println("analogRead() test completed!\n");
+}
+
+void testAnalogWrite() {
+    printSeparator("测试 analogWrite() / Testing analogWrite()");
+
+    Serial.println("PWM breathing on IO9 (Channel 0)...\n");
+
+    ioe1.setPwmFrequency(5000);
+    Serial.println("PWM frequency: 5000 Hz\n");
+
+    unsigned long startTime = millis();
+
+    while (millis() - startTime < 8000) {
+        if (ioe1.analogWrite(0, pwmValue)) {
+            if (pwmValue % 25 == 0) {
+                float duty = (pwmValue * 100.0f) / 255.0f;
+                Serial.print("PWM value: ");
+                Serial.print(pwmValue);
+                Serial.print(" (");
+                Serial.print((int)duty);
+                Serial.println("%)");
+            }
+        }
+
+        // 呼吸效果 / Breathing effect
+        pwmValue += pwmDirection * 5;
+        if (pwmValue >= 255) {
+            pwmValue = 255;
+            pwmDirection = -1;
+        } else if (pwmValue <= 0) {
+            pwmValue = 0;
+            pwmDirection = 1;
+        }
+
+        delay(20);
+    }
+
+    ioe1.analogWrite(0, 0);
+    Serial.println("\nPWM turned off.\n");
+
+    Serial.println("analogWrite() test completed!\n");
+}
+
+void testAttachInterrupt() {
+    printSeparator("测试 attachInterrupt() / Testing attachInterrupt()");
+
+    Serial.println("Configuring button with interrupt (FALLING edge)...\n");
+
+    ioe1.pinMode(PIN_BUTTON, INPUT_PULLUP);
+    buttonPressCount = 0;
+    ioe1.attachInterrupt(PIN_BUTTON, buttonPressed, FALLING);
+
+    Serial.println("Interrupt attached! Press button for 8 seconds...\n");
+
+    unsigned long startTime = millis();
+    int lastCount = 0;
+
+    while (millis() - startTime < 8000) {
+        if (buttonPressCount != lastCount) {
+            Serial.print("Button press detected! Count: ");
+            Serial.println(buttonPressCount);
+            lastCount = buttonPressCount;
+        }
+        delay(50);
+    }
+
+    Serial.print("\nTotal presses: ");
+    Serial.println(buttonPressCount);
+
+    ioe1.detachInterrupt(PIN_BUTTON);
+    Serial.println("Interrupt detached.\n");
+
+    Serial.println("attachInterrupt() test completed!\n");
+}
+
+// ============================
+// Arduino setup() / loop()
+// ============================
+void setup() {
+    Serial.begin(115200);
+    delay(1000);
+
+    Serial.println("\n\n######################################");
+    Serial.println("#     M5IOE1 Pin Test Example      #");
+    Serial.println("######################################\n");
+
+    // 设置日志级别 / Set log level
+    M5IOE1::setLogLevel(M5IOE1_LOG_LEVEL_WARN);
+
+    // 初始化 M5IOE1 / Initialize M5IOE1
+    Serial.println("Initializing M5IOE1...");
+    if (!ioe1.begin(&Wire, I2C_ADDR, I2C_SDA_PIN, I2C_SCL_PIN, I2C_FREQ)) {
+        Serial.println("ERROR: Failed to initialize M5IOE1!");
+        Serial.println("Please check I2C connections and power supply.");
+        while (1) { delay(1000); }
+    }
+    Serial.println("M5IOE1 initialized successfully!\n");
+
+    // 读取设备信息 / Read device info
+    uint16_t uid;
+    uint8_t version;
+    if (ioe1.getUID(&uid)) {
+        Serial.println("Device UID: 0x" + String(uid, HEX));
+    }
+    if (ioe1.getVersion(&version)) {
+        Serial.println("Firmware Version: " + String(version));
+    }
+    Serial.println();
+
+    // 初始化测试引脚 / Initialize test pins
+    Serial.println("Initializing test pins...");
+    ioe1.pinMode(PIN_BUTTON, INPUT_PULLUP);
+    ioe1.pinMode(PIN_LED, OUTPUT);
+    ioe1.digitalWrite(PIN_LED, LOW);
+    Serial.println("Test pins ready!\n");
+
+    delay(2000);
+}
+
+void loop() {
+    static int testStep = 0;
+
+    switch (testStep) {
+        case 0:
+            testPinMode();
+            break;
+        case 1:
+            testDigitalWrite();
+            break;
+        case 2:
+            testDigitalRead();
+            break;
+        case 3:
+            testAnalogRead();
+            break;
+        case 4:
+            testAnalogWrite();
+            break;
+        case 5:
+            testAttachInterrupt();
+            break;
+        default:
+            Serial.println("\n\n######################################");
+            Serial.println("#   All tests completed!             #");
+            Serial.println("#   Restarting in 5 seconds...       #");
+            Serial.println("######################################\n");
+            delay(5000);
+            testStep = -1;
+            break;
+    }
+
+    testStep++;
+
+    if (testStep != 0) {
+        Serial.println("Next test starting in 2 seconds...\n");
+        delay(2000);
+    }
+}
diff --git a/src/M5IOE1.cpp b/src/M5IOE1.cpp
index cf819c0..a020f3c 100644
--- a/src/M5IOE1.cpp
+++ b/src/M5IOE1.cpp
@@ -910,28 +910,30 @@ void M5IOE1::pinMode(uint8_t pin, uint8_t mode) {
     if (!_readReg16(M5IOE1_REG_GPIO_DRV_L, &drvReg)) return;
 
     switch (mode) {
-        case INPUT:
+        case INPUT:  // 0x01
             modeReg &= ~(1 << pin);
             puReg &= ~(1 << pin);
             pdReg &= ~(1 << pin);
             _pinStates[pin].isOutput = false;
             _pinStates[pin].pull = 0;
             break;
-        case INPUT_PULLUP:
+        case PULLUP:  // 0x04 - 仅上拉
+        case INPUT_PULLUP:  // 0x05
             modeReg &= ~(1 << pin);
             puReg |= (1 << pin);
             pdReg &= ~(1 << pin);
             _pinStates[pin].isOutput = false;
             _pinStates[pin].pull = 1;
             break;
-        case INPUT_PULLDOWN:
+        case PULLDOWN:  // 0x08 - 仅下拉
+        case INPUT_PULLDOWN:  // 0x09
             modeReg &= ~(1 << pin);
             puReg &= ~(1 << pin);
             pdReg |= (1 << pin);
             _pinStates[pin].isOutput = false;
             _pinStates[pin].pull = 2;
             break;
-        case OUTPUT:
+        case OUTPUT:  // 0x03
             // 如果此引脚上启用了 PWM 则禁用
             // Disable PWM if enabled on this pin
             if (_isPwmPin(pin)) {
@@ -953,6 +955,38 @@ void M5IOE1::pinMode(uint8_t pin, uint8_t mode) {
             _pinStates[pin].isOutput = true;
             _pinStates[pin].drive = 0;
             break;
+        case OPEN_DRAIN:  // 0x10
+        case OUTPUT_OPEN_DRAIN:  // 0x13
+            // 如果此引脚上启用了 PWM 则禁用
+            // Disable PWM if enabled on this pin
+            if (_isPwmPin(pin)) {
+                uint8_t ch = _getPwmChannel(pin);
+                uint8_t regL = M5IOE1_REG_PWM1_DUTY_L + ch * 2;
+                uint16_t pwmData = 0;
+                if (_readReg16(regL, &pwmData)) {
+                    if (pwmData & ((uint16_t)M5IOE1_PWM_ENABLE << 8)) {
+                        pwmData &= ~((uint16_t)M5IOE1_PWM_ENABLE << 8);
+                        _writeReg16(regL, pwmData);
+                    }
+                }
+            }
+            modeReg |= (1 << pin);
+            puReg &= ~(1 << pin);
+            pdReg &= ~(1 << pin);
+            drvReg |= (1 << pin);  // 开漏
+                                // Open-drain
+            _pinStates[pin].isOutput = true;
+            _pinStates[pin].drive = 1;
+            break;
+        case ANALOG:  // 0xC0
+            // 模拟模式 - 设置为输入，无上拉下拉
+            // Analog mode - set as input, no pull-up/down
+            modeReg &= ~(1 << pin);
+            puReg &= ~(1 << pin);
+            pdReg &= ~(1 << pin);
+            _pinStates[pin].isOutput = false;
+            _pinStates[pin].pull = 0;
+            break;
         default:
             M5IOE1_LOG_E(TAG, "Invalid mode: %d", mode);
             return;
@@ -1386,6 +1420,34 @@ bool M5IOE1::getPwmDuty12bit(uint8_t channel, uint16_t* duty12, bool* polarity,
     return true;
 }
 
+// ============================
+// Arduino 兼容 analogWrite
+// Arduino-compatible analogWrite
+// ============================
+
+bool M5IOE1::analogWrite(uint8_t channel, uint8_t value) {
+    if (channel > 3 || !_initialized) {
+        M5IOE1_LOG_E(TAG, "Invalid channel or not initialized: ch=%d", channel);
+        return false;
+    }
+
+    // 值为 0 时关闭 PWM 输出
+    // Turn off PWM when value is 0
+    if (value == 0) {
+        return setPwmDuty12bit(channel, 0, false, false);
+    }
+
+    // 将 8-bit 值 (0-255) 缩放到 12-bit (0-4095)
+    // Scale 8-bit value (0-255) to 12-bit (0-4095)
+    // 公式：duty12 = (value * 4095) / 255 = value * 16 + value / 16
+    // Formula: duty12 = (value * 4095) / 255 = value * 16 + value / 16
+    uint16_t duty12 = (uint16_t)value * 16 + (uint16_t)value / 16;
+
+    // 设置 PWM，默认启用输出，正常极性
+    // Set PWM with output enabled, normal polarity
+    return setPwmDuty12bit(channel, duty12, false, true);
+}
+
 // ============================
 // NeoPixel LED 功能
 // NeoPixel LED Functions
diff --git a/src/M5IOE1.h b/src/M5IOE1.h
index d7eff8d..3cc2eb9 100644
--- a/src/M5IOE1.h
+++ b/src/M5IOE1.h
@@ -172,43 +172,76 @@ typedef enum {
 #define M5IOE1_PWM_CH3              2   // IO11 (pin index 10)
 #define M5IOE1_PWM_CH4              3   // IO10 (pin index 9)
 
-// ============================
-// GPIO 模式定义（Arduino 兼容）
-// GPIO Mode Definitions (Arduino-compatible)
-// ============================
-#ifndef INPUT
-#define INPUT           0x00
-#endif
-#ifndef OUTPUT
-#define OUTPUT          0x01
-#endif
-#ifndef INPUT_PULLUP
-#define INPUT_PULLUP    0x02
-#endif
-#ifndef INPUT_PULLDOWN
-#define INPUT_PULLDOWN  0x03
-#endif
-
 // ============================
 // GPIO 电平定义
 // GPIO Level Definitions
 // ============================
 #ifndef LOW
-#define LOW             0
+#define LOW             0x0
 #endif
 #ifndef HIGH
-#define HIGH            1
+#define HIGH            0x1
+#endif
+
+// ============================
+// GPIO 模式定义（Arduino 兼容）
+// GPIO Mode Definitions (Arduino-compatible)
+// ============================
+#ifndef INPUT
+#define INPUT             0x01
+#endif
+#ifndef OUTPUT
+#define OUTPUT            0x03
+#endif
+#ifndef PULLUP
+#define PULLUP            0x04
+#endif
+#ifndef INPUT_PULLUP
+#define INPUT_PULLUP      0x05
+#endif
+#ifndef PULLDOWN
+#define PULLDOWN          0x08
+#endif
+#ifndef INPUT_PULLDOWN
+#define INPUT_PULLDOWN    0x09
+#endif
+#ifndef OPEN_DRAIN
+#define OPEN_DRAIN        0x10
+#endif
+#ifndef OUTPUT_OPEN_DRAIN
+#define OUTPUT_OPEN_DRAIN 0x13
+#endif
+#ifndef ANALOG
+#define ANALOG            0xC0
 #endif
 
 // ============================
 // 中断模式定义
 // Interrupt Mode Definitions
 // ============================
+#ifndef DISABLED
+#define DISABLED  0x00
+#endif
 #ifndef RISING
-#define RISING          0x01
+#define RISING    0x01
 #endif
 #ifndef FALLING
-#define FALLING         0x02
+#define FALLING   0x02
+#endif
+#ifndef CHANGE
+#define CHANGE    0x03
+#endif
+#ifndef ONLOW
+#define ONLOW     0x04
+#endif
+#ifndef ONHIGH
+#define ONHIGH    0x05
+#endif
+#ifndef ONLOW_WE
+#define ONLOW_WE  0x0C
+#endif
+#ifndef ONHIGH_WE
+#define ONHIGH_WE 0x0D
 #endif
 
 // ============================
@@ -654,6 +687,23 @@ public:
     bool setPwmDuty12bit(uint8_t channel, uint16_t duty12, bool polarity = false, bool enable = true);
     bool getPwmDuty12bit(uint8_t channel, uint16_t* duty12, bool* polarity, bool* enable);
 
+    /**
+     * @brief Arduino-compatible analogWrite function (PWM output)
+     *        Arduino 兼容的 analogWrite 函数（PWM 输出）
+     * @param channel PWM channel (0-3): M5IOE1_PWM_CH1/CH2/CH3/CH4
+     *               PWM 通道（0-3）：M5IOE1_PWM_CH1/CH2/CH3/CH4
+     *               CH1=IO9, CH2=IO8, CH3=IO11, CH4=IO10
+     * @param value PWM duty cycle (0-255, 8-bit Arduino standard)
+     *              PWM 占空比（0-255，8-bit Arduino 标准）
+     *              0 = 0% duty, 127 = 50% duty, 255 = 100% duty
+     * @return true if successful
+     * @note This function scales 8-bit value to 12-bit internally
+     *       此函数内部将 8-bit 值缩放到 12-bit
+     * @note Value 0 turns off PWM output
+     *       值为 0 时关闭 PWM 输出
+     */
+    bool analogWrite(uint8_t channel, uint8_t value);
+
     // ========================
     // NeoPixel LED 功能
     // NeoPixel LED Functions