【STM32实战⑮】单路光耦继电器模块

#include <Arduino.h>
#include <U8g2lib.h>

// ============================================================
// 15_继电器测试程序
// 模块：单路光耦隔离继电器，高/低电平触发由黄色跳帽选择，本项目实测为低电平触发
//
// 接线：
// 继电器 IN  -> PB1
//         DC+ -> 外部 5V
//         DC- -> GND（必须与 STM32 共地）
// OLED   SCL -> PB8
//        SDA -> PB9
//
// 功能：每 1000 ms 切换一次继电器，OLED 同步显示状态和次数。
// ============================================================

constexpr uint32_t RELAY_PIN = PB1;
constexpr uint32_t OLED_SCL_PIN = PB8;
constexpr uint32_t OLED_SDA_PIN = PB9;
constexpr unsigned long RELAY_INTERVAL_MS = 1000;

// 本项目实测黄色跳帽为低电平触发，保持 true；
// 如果您手上模块的跳帽位置不同，请改为 false 并以实物验证结果为准。
constexpr bool RELAY_ACTIVE_LOW = true;

U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(
    U8G2_R0,
    OLED_SCL_PIN,
    OLED_SDA_PIN,
    U8X8_PIN_NONE
);

bool relayOn = false;
unsigned long previousMillis = 0;
unsigned long relayCycleCount = 0;

uint8_t relayLevel(bool on)
{
    if (RELAY_ACTIVE_LOW)
    {
        return on ? LOW : HIGH;
    }
    return on ? HIGH : LOW;
}

void setRelay(bool on)
{
    relayOn = on;
    digitalWrite(RELAY_PIN, relayLevel(on));
}

void updateOLED()
{
    u8g2.clearBuffer();
    u8g2.setFont(u8g2_font_6x12_tf);
    u8g2.drawStr(0, 12, "15 RELAY");
    u8g2.drawHLine(0, 17, 128);
    u8g2.drawStr(0, 32, "STATUS:");

    u8g2.setFont(u8g2_font_logisoso18_tf);
    u8g2.drawStr(55, 39, relayOn ? "ON" : "OFF");

    u8g2.setFont(u8g2_font_6x12_tf);
    char countText[24];
    snprintf(countText, sizeof(countText), "Count: %lu", relayCycleCount);
    u8g2.drawStr(0, 61, countText);
    u8g2.sendBuffer();
}

void setup()
{
    // 先写入关闭电平，再切换为输出，减少上电瞬间误吸合风险。
    digitalWrite(RELAY_PIN, relayLevel(false));
    pinMode(RELAY_PIN, OUTPUT);
    setRelay(false);

    Serial.begin(115200);
    Serial.println("15 RELAY test start");
    Serial.println(RELAY_ACTIVE_LOW ? "Trigger: ACTIVE LOW (confirmed)" : "Trigger: ACTIVE HIGH (confirmed)");

    u8g2.begin();
    updateOLED();
}

void loop()
{
    const unsigned long currentMillis = millis();
    if (currentMillis - previousMillis < RELAY_INTERVAL_MS)
    {
        return;
    }

    previousMillis = currentMillis;
    setRelay(!relayOn);

    if (!relayOn)
    {
        ++relayCycleCount;
    }

    Serial.print("Relay: ");
    Serial.println(relayOn ? "ON" : "OFF");
    updateOLED();
}