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    BSEC + DevKit + BME688: Odd Gas Resistance Values

    S_Brohl
    New Poster

    BSEC + DevKit + BME688: Odd Gas Resistance Values

    Hello,

    I'm noticing in my bmeraw files as well as my data output from a single BME688 sensor that while running different heater profiles with a duty cycle of 1:0  that I am seeing every so often the gas resistance value: 102400000.000000 on step index zero (and sometimes index 1). I don't believe this is normal as the previous values before it are much smaller. Is there any explaination for why this might be happening?

    I have tried five different 8-sensor development kits and two seperate breakout boards with the BME688 and I still see this value output in my data when running with a duty cycle of 1:0. I am assuming this might be due to the profile transitioning so quickly from the last step index temperature back to the first, but I've also tested this using the default config that comes with the dev kits and see the same thing.

    All of these sensors have undergone a 72hr burn-in period, but I am still wondering, do I need to allow the sensors to run 5 minutes before I can assume I am receiving genuine data?

    Any insight into this anomaly would be greatly appreciated!

    Also, here is some data so you can see what I am talking about:

    Sensor 0:

    Time since power-onRTC Time in SecondsTempPressureRel. HumidityGas ResistanceHP Step IndexScanning enabledHeater ProfileDuty Cycle
    1160091.65E+0929.26295999.916724.4637310240000001heater_301duty_1
    1218041.65E+0928.66775999.90624.446728407440811heater_301duty_1
    1220841.65E+0928.90533999.854424.49614475174021heater_301duty_1
    1239801.65E+0929.55556999.916924.549414136329.2531heater_301duty_1
    1259401.65E+0929.71061999.934724.453993925251.541heater_301duty_1
    1279001.65E+0929.84066999.917424.447563477817.7551heater_301duty_1
    1281801.65E+0929.98571999.888224.35675383880.031361heater_301duty_1
    1301401.65E+0930.48339999.88824.24382520589.718871heater_301duty_1
    1321001.65E+0930.63845999.901524.10568579841.437581heater_301duty_1
    1339321.65E+0930.75849999.907123.84773614277.12590heater_301duty_1
    1343821.65E+0930.16327999.943723.7354210240000001heater_301duty_1
    1401141.65E+0929.51054999.956123.768169453444011heater_301duty_1
    1403941.65E+0929.76313999.934723.79697516031521heater_301duty_1
    1423541.65E+0930.40336999.901623.880544527217.531heater_301duty_1
    1443141.65E+0930.53841999.897323.863714074608.2541heater_301duty_1
    1462741.65E+0930.65095999.900123.674853757798.2551heater_301duty_1
    1465541.65E+0930.791999.900123.73821406268.593861heater_301duty_1
    1483741.65E+0931.29619999.911923.57239548620.437571heater_301duty_1
    1503341.65E+0931.48126999.920923.38349603417.812581heater_301duty_1
    1523061.65E+0931.6013999.922523.19007642610.62590heater_301duty_1
    1527501.65E+0930.99358999.892523.2211110240000001heater_301duty_1
    1584521.65E+0930.28081999.898723.1070110240000011heater_301duty_1
    1587321.65E+0930.54591999.848223.16282563993121heater_301duty_1
    1606921.65E+0931.21866999.899223.25308476002331heater_301duty_1
    1626521.65E+0931.36121999.928123.15172428900541heater_301duty_1
    1646121.65E+0931.44874999.926323.035893902810.7551heater_301duty_1
    1648921.65E+0931.5888999.898822.92911419758.156361heater_301duty_1
    1667121.65E+0932.07648999.900622.92118566841.937571heater_301duty_1
    1686721.65E+0932.25155999.889122.74788629572.687581heater_301duty_1
    1707261.65E+0932.3966999.907122.66266661926.312590heater_301duty_1
    1710281.65E+0931.73385999.929722.4628510240000001heater_301duty_1
    1768241.65E+0931.04359999.877322.5153210240000011heater_301duty_1
    1771061.65E+0931.31369999.905822.55525734686.521heater_301duty_1
    1790771.65E+0931.97894999.976722.628064870392.531heater_301duty_1
    1809101.65E+0932.124999.937122.56409436790241heater_301duty_1
    1828701.65E+0932.23154999.947322.455173991230.2551heater_301duty_1
    1831501.65E+0932.37159999.928322.44376428451.87561heater_301duty_1
    1851111.65E+0932.86929999.926522.35142576901.437571heater_301duty_1
    1871061.65E+0933.02935999.962622.16148641403.062581heater_301duty_1
    1890921.65E+0933.14439999.939121.9686678370.312590heater_301duty_1
    1895461.65E+0932.40911999.921621.9551310240000001heater_301duty_1
    1952271.65E+0931.80138999.928121.971610240000011heater_301duty_1
    1953681.65E+0932.07148999.932321.921545734686.521heater_301duty_1
    1973281.65E+0932.72173999.935622.08744879094.531heater_301duty_1
    1993001.65E+0932.84678999.901222.00623439602941heater_301duty_1
    2012611.65E+0932.95432999.93121.876394245659.551heater_301duty_1
    2015411.65E+0933.09938999.923121.87577426844.531361heater_301duty_1
    2035631.65E+0933.60708999.944621.76272578367.687571heater_301duty_1
    2053871.65E+0933.76964999.969821.67355652437.062581heater_301duty_1
    2073721.65E+0933.88219999.970921.45971690026.937590heater_301duty_1
    2078121.65E+0933.25694999.944321.3491610240000001heater_301duty_1
    2134531.65E+0932.50665999.922921.456510240000011heater_301duty_1
    2137571.65E+0932.77175999.894821.405985914801.521heater_301duty_1
    2157171.65E+0933.44952999.936321.60435018070.531heater_301duty_1
    2176771.65E+0933.56956999.949821.49652454227941heater_301duty_1
    2196401.65E+0933.6621999.987521.392194142604.2551heater_301duty_1
    2199601.65E+0933.80966999.981421.4074435559.343861heater_301duty_1
    2217811.65E+0934.29736999.978421.32441590371.87571heater_301duty_1
    2237441.65E+0934.46743999.986221.11467660006.437581heater_301duty_1
    2257281.65E+0934.59248999.959820.94943702091.187590heater_301duty_1
    2261541.65E+0933.97222999.98320.8453210240000001heater_301duty_1
    2318011.65E+0933.1744999.90620.9657110240000011heater_301duty_1
    2320811.65E+0933.43201999.902921.01426056931.521heater_301duty_1
    2340411.65E+0934.12228999.9521.08634510723231heater_301duty_1
    2360011.65E+0934.26734999.957621.017164611314.541heater_301duty_1
    2379031.65E+0934.35738999.964120.918054136329.2551heater_301duty_1
    2381841.65E+0934.50244999.92120.9014437233.12561heater_301duty_1
    2401441.65E+0934.99014999.929220.81813600762.687571heater_301duty_1
    2421031.65E+0935.1427999.944620.63906673684.187581heater_301duty_1
    2440881.65E+0935.25275999.922920.48881709386.937590heater_301duty_1
    2445321.65E+0934.61999999.940620.3898910240000001heater_301duty_1
    2501511.65E+0933.84967999.933420.5543710240000011heater_301duty_1
    2504451.65E+0934.11728999.934720.582296114573.521heater_301duty_1
    2524331.65E+0934.77505999.938620.71984518481031heater_301duty_1
    2544361.65E+0934.9051999.967120.591944588070.541heater_301duty_1
    2562571.65E+0935.00264999.959920.488184174267.551heater_301duty_1
    2565371.65E+0935.1452999.906920.49226437513.343861heater_301duty_1
    2584961.65E+0935.65041999.952520.36266604486.437571heater_301duty_1
    2604571.65E+0935.79798999.955920.22542669718.7581heater_301duty_1
    2624491.65E+0935.90052999.958220.05914708650.590heater_301duty_1
    2628861.65E+0935.27526999.964419.9770910240000001heater_301duty_1
    2685441.65E+0934.45492999.939120.1230210240000011heater_301duty_1
    2688231.65E+0934.71753999.922620.13989612142721heater_301duty_1
    2708101.65E+0935.42782999.948820.20665511680231heater_301duty_1
    2727701.65E+0935.54537999.96820.109534706693.541heater_301duty_1
    2747291.65E+0935.6179999.985819.967684152052.7551heater_301duty_1
    2750101.65E+0935.76296999.938120.03456437793.937561heater_301duty_1
    2769691.65E+0936.25067999.979919.90888595521.937571heater_301duty_1
    2787901.65E+0936.41824999.991319.74168667753.581heater_301duty_1
    2807751.65E+0936.53079999.98219.57631718344.437590heater_301duty_1
    2812021.65E+0935.88802999.965519.473110240000001heater_301duty_1
    2869111.65E+0935.05517999.947819.6552110240000011heater_301duty_1
    2871901.65E+0935.31527999.897619.708146152459.521heater_301duty_1
    2891511.65E+0936.01057999.972519.762745112012.531heater_301duty_1
    2911111.65E+0936.13062999.96819.681544580374.541heater_301duty_1
    2930721.65E+0936.22316999.990419.593394111417.7551heater_301duty_1
    2933511.65E+0936.36572999.972819.59197438637.812561heater_301duty_1
    2953111.65E+0936.85343999.971619.49745589861.7571heater_301duty_1
    2972711.65E+0936.98349999.955419.32804670376.437581heater_301duty_1
    2991171.65E+0937.09353999.95819.19403715333.562590heater_301duty_1
    2996231.65E+0936.458261000.0119.0971710240000001heater_301duty_1
    3052231.65E+0935.44783999.922818.4342110240000011heater_301duty_1
    3055031.65E+0935.71544999.91318.424366135180.521heater_301duty_1
    3074641.65E+0936.37322999.99418.11216525971131heater_301duty_1
    3094461.65E+0936.47076999.982417.710544670467.541heater_301duty_1
    3114131.65E+0936.54831000.02117.370484242361.551heater_301duty_1
    3116941.65E+0936.68086999.997917.33181451101.312561heater_301duty_1
    3136651.65E+0937.16607999.979217.04103627835.687571heater_301duty_1
    3155881.65E+0937.27361999.992616.84199711605.312581heater_301duty_1
    3175741.65E+0937.353651000.00716.48828759643.937590heater_301duty_1
    3180131.65E+0936.690861000.02716.3094910240000001heater_301duty_1
    3236501.65E+0935.84049999.945916.2079710240000011heater_301duty_1
    3239301.65E+0936.12061999.964716.23817675768221heater_301duty_1
    3259161.65E+0936.7784999.982716.247995675095.531heater_301duty_1
    3277701.65E+0936.87844999.949616.131195145728.541heater_301duty_1
    3297301.65E+0936.94597999.982816.00764460742451heater_301duty_1
    3300101.65E+0937.08853999.970216.06607469401.781361heater_301duty_1
    3319441.65E+0937.57124999.979415.9136364687371heater_301duty_1
    3339041.65E+0937.6988999.993315.73728736161.062581heater_301duty_1
    3358901.65E+0937.78634999.981715.5742277782090heater_301duty_1
    3363271.65E+0937.148561000.01115.4854210240000001heater_301duty_1
    3419461.65E+0936.26318999.990815.5713610240000011heater_301duty_1
    3422261.65E+0936.54079999.992615.454177000213.521heater_301duty_1
    3442101.65E+0937.20608999.993915.63031579554331heater_301duty_1
    3461821.65E+0937.311131000.01215.539425204574.541heater_301duty_1
    3481821.65E+0937.373661000.00615.461564710753.551heater_301duty_1
    3484621.65E+0937.51622999.971715.33719471346.37561heater_301duty_1
    3502821.65E+0937.97892999.991915.35586651192.37571heater_301duty_1
    3522431.65E+0938.101481000.00515.22529741760.2581heater_301duty_1
    3542281.65E+0938.191521000.01715.10326784975.062590heater_301duty_1
    3546831.65E+0937.551241000.00615.0254310240000001heater_301duty_1
    3604271.65E+0936.660851000.00815.1270110240000011heater_301duty_1
    3607061.65E+0936.94347999.978915.16144700470321heater_301duty_1
    3625651.65E+0937.598761000.02715.240175870297.531heater_301duty_1
    3645381.65E+0937.706311000.03215.184925150581.541heater_301duty_1
    3665261.65E+0937.778841000.04815.11778428227951heater_301duty_1
    3668051.65E+0937.92391000.03315.21624428990.37561heater_301duty_1
    3687661.65E+0938.391611000.06415.04251463978.2571heater_301duty_1
    3707251.65E+0938.509161000.09114.91179445507.937581heater_301duty_1
    3725711.65E+0938.58921000.114.78432422878.37590heater_301duty_1
    3730101.65E+0937.946411000.08214.691866648338801heater_301duty_1
    3787791.65E+0937.073521000.03514.789824676132811heater_301duty_1
    3789631.65E+0937.328641000.01314.802442718884.7521heater_301duty_1
    3809351.65E+0937.991431000.05314.875761854652.531heater_301duty_1
    3829091.65E+0938.093981000.06214.795031472322.12541heater_301duty_1
    3848981.65E+0938.14651000.06914.65131217598.12551heater_301duty_1
    3851791.65E+0938.294071000.0614.69895195121.953161heater_301duty_1
    3871391.65E+0938.779291000.09114.57652263713.62571heater_301duty_1
    3890981.65E+0938.904341000.08714.45144271258.281381heater_301duty_1
    3909431.65E+0938.976881000.08614.28858272557.906390heater_301duty_1

     

    5 REPLIES 5
    BSTRobin
    Community Moderator

    Re: BSEC + DevKit + BME688: Odd Gas Resistance Values

    Hi S_Brohl,

    If you run BSEC, you could add BSEC accuracy value to output list to see current BSEC calibration status.

    By the way, could we know more deatailed about your software?

    S_Brohl
    New Poster

    Re: BSEC + DevKit + BME688: Odd Gas Resistance Values

    Hi Robin,

    I'll try this out with my single sensor and reply back with any findings.

    As for my software setup we are currently using the DevKits as they come preinstalled on a Huzzah32 ESP32 microcontroller. I've reflashed all five of the boards and loaded back the default configurations that came preinstalled to the SD cards.

    For my single sensor setup I am using the provided basic-config.ino Arduino sketch that comes with the BSEC2 library and it is flashed to an ESP8266 Microcontroller which is connected to the sensor via I2C.

    I'm almost thinking this might be a hardware issue now as I look at past data from early on in our gas exploration and see  I see the same erroneous data persisting right after initial exposure to our test substances. It seems from that point on the sensors are no longer working as expected.

    S_Brohl
    New Poster

    Re: BSEC + DevKit + BME688: Odd Gas Resistance Values


    I have a brand new dev kit which I am going to run side-by-side to one of the suspected faulty dev kits. I'll post some side-by-side comparison of what they both see shortly.

    Update 2: On my single sensor I have enabled the BSEC Stabilization and Run-In Status outputs.

    They both remain at:
       > Stabilization Status: 1.00 (Stabilization is finished)
       > Run in Status:0.00 (Stabilization is on-going)

     

    BSTRobin
    Community Moderator

    Re: BSEC + DevKit + BME688: Odd Gas Resistance Values

    Hi S_Brohl,

    Official example code could work under ESP32 and ESP8266 hardware platform.
    If the configuration file in the example is used, the change of gas resistance depends on the composition of the surrounding air.

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