Thanks Robin for your recommendation. To be able to record the gas resistance value of your recommendation heater profile: /* Heater temperature in degree Celsius */ uint16_t tempProf[10] = {400, 200, 225, 250, 275, 300, 325, 350, 375, 400}; /* Heating duration in milliseconds */ uint16_t durProf[10] = {1000, 1000, 1000, 1000, 1000,1000,1000,1000,1000,1000}; I have to use the FORCED_MODE as the following code: bme.setHeaterProf(400, 1000); bme.setOpMode(BME68X_FORCED_MODE); delayMicroseconds(bme.getMeasDur()); if (bme.fetchData()) { bme.getData(data); Serial.print(String(millis()) + ", "); Serial.print(String(data.temperature) + ", "); Serial.print(String(data.pressure) + ", "); Serial.print(String(data.humidity) + ", "); Serial.print(data.status, HEX); Serial.print(" 400C: "); Serial.print(String(data.gas_resistance) + ", "); } // BME68X_FORCED_MODE for (int temp = 175; temp <= 400; temp += 25) { // Temperature range from 200 to 400°C with 25°C steps startMillis = millis(); bme.setHeaterProf(temp, 1000); // Set the gas heater temperature and duration bme.setOpMode(BME68X_FORCED_MODE); if (bme.fetchData()) { endMillis = millis(); Serial.print(endMillis - startMillis); Serial.print(" ms "); Serial.print(temp); Serial.print("C: "); bme.getData(data); Serial.print(data.gas_resistance); // Convert gas resistance to kOhm Serial.print(", "); } } Serial.println(); delay(10000); } The Serial Monitor is as following: 24278, 33.04, 99813.79, 34.93, B0 400C: 126952.64, 936 ms 200C: 6863846.00, 1023 ms 225C: 2834602.00, 1033 ms 250C: 1507545.12, 1033 ms 275C: 821335.50, 1033 ms 300C: 472651.75, 1033 ms 325C: 256000.00, 1022 ms 350C: 156958.92, 1033 ms 375C: 114669.66, 1033 ms 400C: 101446.41, 43584, 33.08, 99813.24, 33.68, B0 400C: 129949.24, 936 ms 200C: 6991252.50, 1022 ms 225C: 2913229.00, 1033 ms 250C: 1528643.37, 1033 ms 275C: 820841.69, 1033 ms 300C: 469724.78, 1033 ms 325C: 251473.48, 1022 ms 350C: 154963.69, 1033 ms 375C: 112775.33, 1032 ms 400C: 97728.57, 62889, 33.13, 99814.62, 35.31, B0 400C: 123462.74, 936 ms 200C: 6574639.00, 1022 ms 225C: 2740716.00, 1033 ms 250C: 1444287.75, 1033 ms 275C: 802507.81, 1033 ms 300C: 463034.13, 1023 ms 325C: 251658.89, 1033 ms 350C: 156383.63, 1033 ms 375C: 114746.75, 1033 ms 400C: 101870.27, 82195, 33.13, 99814.91, 33.38, B0 400C: 131551.91, 935 ms 200C: 7620465.00, 1022 ms 225C: 3246285.00, 1033 ms 250C: 1681100.00, 1033 ms 275C: 911843.25, 1033 ms 300C: 519401.47, 1022 ms 325C: 277883.31, 1033 ms 350C: 168587.42, 1033 ms 375C: 121962.84, 1033 ms 400C: 106113.99, 101501, 33.14, 99812.82, 32.57, B0 400C: 134242.27, 935 ms 200C: 7884504.50, 1022 ms 225C: 3351882.25, 1033 ms 250C: 1724631.62, 1033 ms 275C: 927326.25, 1033 ms 300C: 532362.88, 1022 ms 325C: 281318.69, 1033 ms 350C: 171812.08, 1033 ms 375C: 122576.01, 1033 ms 400C: 106844.74, 120807, 33.12, 99814.49, 32.48, B0 400C: 135092.34, 936 ms 200C: 8059026.00, 1022 ms 225C: 3406237.00, 1033 ms 250C: 1753424.62, 1033 ms 275C: 958577.13, 1033 ms 300C: 544680.88, 1033 ms 325C: 288939.06, 1022 ms 350C: 174446.34, 1033 ms 375C: 125736.74, 1033 ms 400C: 108474.58, 140112, 33.10, 99815.96, 32.36, B0 400C: 135413.91, 936 ms 200C: 8241448.50, 1022 ms 225C: 3482253.00, 1033 ms 250C: 1791384.25, 1033 ms 275C: 974310.19, 1033 ms 300C: 553513.50, 1022 ms 325C: 294168.34, 1033 ms 350C: 177716.08, 1033 ms 375C: 127331.51, 1033 ms 400C: 109589.04, Is it ok? I tried to use the SEQUENTIAL-MODE but I cannot extract the gas reristance value at each temperature steps. Thanks in advance, Best regards,
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