/* HocLapTrinhRobot G2 05 - Loc nhieu du lieu cam bien Board: ESP32-S3 DevKit Hardware: SHT31 I2C, LDR voltage divider, MQ-135 analog, LED, active buzzer */ #include const int PIN_I2C_SDA = 8; const int PIN_I2C_SCL = 9; const int PIN_LDR = 4; const int PIN_MQ135 = 6; const int PIN_LED = 2; const int PIN_BUZZER = 15; const uint8_t SHT31_ADDR = 0x44; const unsigned long SAMPLE_INTERVAL_MS = 1000; const unsigned long MQ_WARMUP_MS = 60000; const float EMA_ALPHA = 0.18f; int gasBaselineRaw = 1800; bool filtersReady = false; unsigned long lastSampleMs = 0; float tempFiltered = 0.0f; float humFiltered = 0.0f; float lightFiltered = 0.0f; float airFiltered = 0.0f; uint8_t crc8(const uint8_t *data, int len) { uint8_t crc = 0xFF; for (int i = 0; i < len; i++) { crc ^= data[i]; for (int bit = 0; bit < 8; bit++) { crc = (crc & 0x80) ? (crc << 1) ^ 0x31 : (crc << 1); } } return crc; } bool readSht31(float &temperatureC, float &humidityPercent) { Wire.beginTransmission(SHT31_ADDR); Wire.write(0x24); Wire.write(0x00); if (Wire.endTransmission() != 0) { return false; } delay(20); if (Wire.requestFrom((int)SHT31_ADDR, 6) != 6) { return false; } uint8_t data[6]; for (int i = 0; i < 6; i++) { data[i] = Wire.read(); } if (crc8(data, 2) != data[2] || crc8(data + 3, 2) != data[5]) { return false; } uint16_t rawTemp = ((uint16_t)data[0] << 8) | data[1]; uint16_t rawHum = ((uint16_t)data[3] << 8) | data[4]; temperatureC = -45.0f + 175.0f * ((float)rawTemp / 65535.0f); humidityPercent = 100.0f * ((float)rawHum / 65535.0f); return true; } int readAnalogAverage(int pin, int sampleCount) { long total = 0; for (int i = 0; i < sampleCount; i++) { total += analogRead(pin); delay(2); } return total / sampleCount; } float constrainFloat(float value, float low, float high) { if (value < low) return low; if (value > high) return high; return value; } float lightPercentFromRaw(int raw) { return constrainFloat((raw / 4095.0f) * 100.0f, 0.0f, 100.0f); } float airScoreFromRaw(int raw) { int delta = raw - gasBaselineRaw; float score = delta / 12.0f; return constrainFloat(score, 0.0f, 100.0f); } float updateEma(float previous, float sample, bool initialized) { if (!initialized) { return sample; } return previous + EMA_ALPHA * (sample - previous); } void calibrateGasBaseline() { gasBaselineRaw = readAnalogAverage(PIN_MQ135, 40); Serial.print("baseline_gas_raw="); Serial.println(gasBaselineRaw); } void resetFilters() { filtersReady = false; Serial.println("filters_reset=OK"); } void handleSerialCommand() { if (!Serial.available()) { return; } String command = Serial.readStringUntil('\n'); command.trim(); command.toUpperCase(); if (command == "BASELINE GAS") { calibrateGasBaseline(); } else if (command == "RESET FILTER") { resetFilters(); } else if (command == "STATUS") { Serial.print("status baseline="); Serial.print(gasBaselineRaw); Serial.print(" alpha="); Serial.print(EMA_ALPHA, 2); Serial.print(" filtersReady="); Serial.println(filtersReady ? "YES" : "NO"); } else if (command.length() > 0) { Serial.println("commands: BASELINE GAS | RESET FILTER | STATUS"); } } void updateAlert(float tempC, float humidity, float lightPercent, float airScore) { bool gasReady = millis() >= MQ_WARMUP_MS; bool alert = tempC > 34.0f || humidity > 85.0f || lightPercent < 15.0f || (gasReady && airScore > 60.0f); digitalWrite(PIN_LED, alert ? HIGH : LOW); if (alert && (millis() / 250) % 2 == 0) { digitalWrite(PIN_BUZZER, HIGH); } else { digitalWrite(PIN_BUZZER, LOW); } } void printCsvHeader() { Serial.println("t_ms,sht,temp_raw,temp_f,hum_raw,hum_f,light_raw,light_f,mq_raw,air_raw,air_f,alert"); } void setup() { Serial.begin(115200); delay(400); pinMode(PIN_LED, OUTPUT); pinMode(PIN_BUZZER, OUTPUT); digitalWrite(PIN_LED, LOW); digitalWrite(PIN_BUZZER, LOW); analogReadResolution(12); Wire.begin(PIN_I2C_SDA, PIN_I2C_SCL); Serial.println("G2 05 sensor filtering ready"); Serial.println("commands: BASELINE GAS | RESET FILTER | STATUS"); printCsvHeader(); } void loop() { handleSerialCommand(); unsigned long now = millis(); if (now - lastSampleMs < SAMPLE_INTERVAL_MS) { updateAlert(tempFiltered, humFiltered, lightFiltered, airFiltered); return; } lastSampleMs = now; float tempRaw = tempFiltered; float humRaw = humFiltered; bool shtOk = readSht31(tempRaw, humRaw); int ldrRaw = readAnalogAverage(PIN_LDR, 12); int mqRaw = readAnalogAverage(PIN_MQ135, 12); float lightRaw = lightPercentFromRaw(ldrRaw); float airRaw = airScoreFromRaw(mqRaw); if (!shtOk && !filtersReady) { tempRaw = 0.0f; humRaw = 0.0f; } tempFiltered = updateEma(tempFiltered, tempRaw, filtersReady); humFiltered = updateEma(humFiltered, humRaw, filtersReady); lightFiltered = updateEma(lightFiltered, lightRaw, filtersReady); airFiltered = updateEma(airFiltered, airRaw, filtersReady); filtersReady = true; bool gasReady = now >= MQ_WARMUP_MS; bool alert = tempFiltered > 34.0f || humFiltered > 85.0f || lightFiltered < 15.0f || (gasReady && airFiltered > 60.0f); updateAlert(tempFiltered, humFiltered, lightFiltered, airFiltered); Serial.print(now); Serial.print(','); Serial.print(shtOk ? "OK" : "ERR"); Serial.print(','); Serial.print(tempRaw, 2); Serial.print(','); Serial.print(tempFiltered, 2); Serial.print(','); Serial.print(humRaw, 2); Serial.print(','); Serial.print(humFiltered, 2); Serial.print(','); Serial.print(ldrRaw); Serial.print(','); Serial.print(lightFiltered, 1); Serial.print(','); Serial.print(mqRaw); Serial.print(','); Serial.print(airRaw, 1); Serial.print(','); Serial.print(airFiltered, 1); Serial.print(','); Serial.println(alert ? "YES" : "NO"); }

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