Software
Code - https://github.com/PrivateKit/private-kit/tree/magnetometer
Commit 334cd86
Environment
Device A - Samsung Galaxy S8 running Android 9
Device B - Google Pixel 3a running Android 10
Linux system acting as server endpoint (phones connected via USB)
Limitations
As there is no internet deployed back-end, the devices needed to be USB connected, which limited the testing range.
Human error in distance measurement +/- 2cm
Only Android and two types of device used
The phones remained flat, although it is known that tilting the phone changes the outputs
Method
Built and installed APK via USB to both phones
Over 45 minutes (with a tape measure) moving the two devices running the app around at distances between 0 and 320cm (changing distance every two minutes)
Extracted the readings from the phone databases manually (method)
Observations & Analysis
It is notable that no new permissions were requested by the phone.
In terms of the results, this requires data science support. The x,y,z points need to be transformed to a value that should correlate with distance. See work to prepare the data here: https://github.com/AdamLeonSmith/privkittools/blob/master/Magnetometer.ipynb
Detailed Results
Device A
[{""x"":138.1199951171875,""y"":84.77999877929688,""z"":-25.68000030517578,""timestamp"":1588416628368},{""x"":142.0800018310547,""y"":84.18000030517578,""z"":-26.69999885559082,""timestamp"":1588416678417},{""x"":141.4199981689453,""y"":83.93999481201172,""z"":-26.34000015258789,""timestamp"":1588416728419},{""x"":141.83999633789062,""y"":81.47999572753906,""z"":-27.35999870300293,""timestamp"":1588416778419},{""x"":141.4199981689453,""y"":81.9000015258789,""z"":-27.299999237060547,""timestamp"":1588416828618},{""x"":143.63999938964844,""y"":78.18000030517578,""z"":-30.119998931884766,""timestamp"":1588416878621},{""x"":141.3000030517578,""y"":79.5,""z"":-28.739999771118164,""timestamp"":1588416928819},{""x"":141.77999877929688,""y"":79.55999755859375,""z"":-28.439998626708984,""timestamp"":1588416978919},{""x"":147.72000122070312,""y"":114,""z"":-15.839999198913574,""timestamp"":1588417029116},{""x"":147.59999084472656,""y"":113.27999877929688,""z"":-15,""timestamp"":1588417079309},{""x"":152.27999877929688,""y"":99.29999542236328,""z"":-43.31999969482422,""timestamp"":1588417129503},{""x"":152.75999450683594,""y"":100.6199951171875,""z"":-45.05999755859375,""timestamp"":1588417179694},{""x"":188.39999389648438,""y"":111.41999816894531,""z"":-21.84000015258789,""timestamp"":1588417229886},{""x"":188.8199920654297,""y"":109.25999450683594,""z"":-21.059999465942383,""timestamp"":1588417280083},{""x"":188.22000122070312,""y"":108.18000030517578,""z"":-19.68000030517578,""timestamp"":1588417330253},{""x"":189.77999877929688,""y"":97.5,""z"":-16.85999870300293,""timestamp"":1588417380449},{""x"":190.3199920654297,""y"":98.69999694824219,""z"":-16.139999389648438,""timestamp"":1588417430644},{""x"":179.87998962402344,""y"":93.95999908447266,""z"":-4.980000019073486,""timestamp"":1588417480842},{""x"":185.6999969482422,""y"":94.13999938964844,""z"":-1.9199999570846558,""timestamp"":1588417531037},{""x"":187.97999572753906,""y"":91.37999725341797,""z"":-4.679999828338623,""timestamp"":1588417581227},{""x"":3.5399999618530273,""y"":6.899999618530273,""z"":58.2599983215332,""timestamp"":1588417631422},{""x"":2.6399998664855957,""y"":5.579999923706055,""z"":56.69999694824219,""timestamp"":1588417681616},{""x"":181.44000244140625,""y"":100.73999786376953,""z"":-22.68000030517578,""timestamp"":1588417731688},{""x"":175.0800018310547,""y"":105.5999984741211,""z"":-22.079999923706055,""timestamp"":1588417781885},{""x"":174.4199981689453,""y"":105.1199951171875,""z"":-21.600000381469727,""timestamp"":1588417832080},{""x"":173.45999145507812,""y"":104.87999725341797,""z"":-21,""timestamp"":1588417918398},{""x"":172.86000061035156,""y"":105.83999633789062,""z"":-20.939998626708984,""timestamp"":1588417968588},{""x"":172.9199981689453,""y"":104.87999725341797,""z"":-22.559999465942383,""timestamp"":1588418018786},{""x"":173.5800018310547,""y"":105.29999542236328,""z"":-24.719999313354492,""timestamp"":1588418068972},{""x"":175.25999450683594,""y"":104.39999389648438,""z"":-25.559999465942383,""timestamp"":1588418119165},{""x"":173.51998901367188,""y"":106.43999481201172,""z"":-22.739999771118164,""timestamp"":1588418169165},{""x"":173.94000244140625,""y"":105.65999603271484,""z"":-22.920000076293945,""timestamp"":1588418219361},{""x"":172.0800018310547,""y"":106.68000030517578,""z"":-22.020000457763672,""timestamp"":1588418269364},{""x"":172.55999755859375,""y"":106.31999969482422,""z"":-21.119998931884766,""timestamp"":1588418319386},{""x"":172.739990234375,""y"":106.86000061035156,""z"":-19.619998931884766,""timestamp"":1588418369389},{""x"":173.8199920654297,""y"":106.43999481201172,""z"":-22.19999885559082,""timestamp"":1588418419403},{""x"":172.9199981689453,""y"":105.89999389648438,""z"":-21.65999984741211,""timestamp"":1588418469411},{""x"":172.55999755859375,""y"":106.91999816894531,""z"":-21.420000076293945,""timestamp"":1588418519594},{""x"":173.39999389648438,""y"":106.37999725341797,""z"":-23.51999855041504,""timestamp"":1588418569787},{""x"":174.239990234375,""y"":107.04000091552734,""z"":-22.260000228881836,""timestamp"":1588418619979},{""x"":172.13999938964844,""y"":106.91999816894531,""z"":-20.939998626708984,""timestamp"":1588418670168},{""x"":171.4199981689453,""y"":107.15999603271484,""z"":-18.779998779296875,""timestamp"":1588418720361},{""x"":171.3000030517578,""y"":106.97999572753906,""z"":-20.15999984741211,""timestamp"":1588418770550},{""x"":177.95999145507812,""y"":101.69999694824219,""z"":-20.8799991607666,""timestamp"":1588418820747},{""x"":178.1999969482422,""y"":99.83999633789062,""z"":-20.760000228881836,""timestamp"":1588418870937},{""x"":178.8000030517578,""y"":100.07999420166016,""z"":-22.079999923706055,""timestamp"":1588418921129},{""x"":178.0800018310547,""y"":100.43999481201172,""z"":-19.3799991607666,""timestamp"":1588418971327},{""x"":166.9199981689453,""y"":109.13999938964844,""z"":-21.239999771118164,""timestamp"":1588419021524},{""x"":167.63999938964844,""y"":109.07999420166016,""z"":-20.760000228881836,""timestamp"":1588419071719},{""x"":167.16000366210938,""y"":109.37999725341797,""z"":-19.439998626708984,""timestamp"":1588419121911},{""x"":166.55999755859375,""y"":108.18000030517578,""z"":-20.69999885559082,""timestamp"":1588419172101}]" WHERE key = "MAGNETOMETER_DATA"
Device B
UPDATE catalystlocalstorage SET value = "[{""x"":40.0589599609375,""y"":-15.680082321166992,""z"":-32.017913818359375,""timestamp"":1588412935548},{""x"":40.0699462890625,""y"":-15.63351058959961,""z"":-31.241363525390625,""timestamp"":1588412985839},{""x"":40.2173957824707,""y"":-14.890460968017578,""z"":-31.447830200195312,""timestamp"":1588413036124},{""x"":40.292964935302734,""y"":-14.936300277709961,""z"":-32.6888427734375,""timestamp"":1588413086409},{""x"":39.4268684387207,""y"":-15.191373825073242,""z"":-31.197006225585938,""timestamp"":1588413136698},{""x"":40.090423583984375,""y"":-15.107881546020508,""z"":-30.815773010253906,""timestamp"":1588413186985},{""x"":39.909942626953125,""y"":-15.434043884277344,""z"":-30.728759765625,""timestamp"":1588413237280},{""x"":39.712791442871094,""y"":-15.513147354125977,""z"":-30.79412841796875,""timestamp"":1588413287587},{""x"":39.52531433105469,""y"":-15.298532485961914,""z"":-30.592002868652344,""timestamp"":1588413337885},{""x"":39.171905517578125,""y"":-15.270963668823242,""z"":-30.921676635742188,""timestamp"":1588413388186},{""x"":39.334922790527344,""y"":-14.99114990234375,""z"":-29.86119842529297,""timestamp"":1588413438490},{""x"":39.59674835205078,""y"":-15.436887741088867,""z"":-30.266990661621094,""timestamp"":1588413488801},{""x"":39.964786529541016,""y"":-15.217239379882812,""z"":-30.97374725341797,""timestamp"":1588413539118},{""x"":39.67028045654297,""y"":-15.35910415649414,""z"":-31.351356506347656,""timestamp"":1588413589792},{""x"":39.382930755615234,""y"":-15.176273345947266,""z"":-30.824935913085938,""timestamp"":1588413640116},{""x"":39.980655670166016,""y"":-15.649593353271484,""z"":-29.908164978027344,""timestamp"":1588413690429},{""x"":39.92919921875,""y"":-15.789295196533203,""z"":-30.950103759765625,""timestamp"":1588413740741},{""x"":31.37622833251953,""y"":-15.684326171875,""z"":-36.744293212890625,""timestamp"":1588413791045},{""x"":31.305578231811523,""y"":-15.669544219970703,""z"":-36.853553771972656,""timestamp"":1588413841343},{""x"":31.410688400268555,""y"":-16.20936393737793,""z"":-36.65717315673828,""timestamp"":1588413891634},{""x"":31.475975036621094,""y"":-15.96141242980957,""z"":-35.90857696533203,""timestamp"":1588413941933},{""x"":31.111242294311523,""y"":-16.04218101501465,""z"":-36.68970489501953,""timestamp"":1588413992238},{""x"":31.280593872070312,""y"":-16.210458755493164,""z"":-35.88287353515625,""timestamp"":1588414042532},{""x"":31.02417755126953,""y"":-16.073787689208984,""z"":-35.96180725097656,""timestamp"":1588414092840},{""x"":30.865154266357422,""y"":-15.843467712402344,""z"":-35.852264404296875,""timestamp"":1588414143155},{""x"":31.34894561767578,""y"":-15.808174133300781,""z"":-36.606468200683594,""timestamp"":1588414193464},{""x"":31.34105682373047,""y"":-16.256397247314453,""z"":-36.844764709472656,""timestamp"":1588414243769},{""x"":30.79733657836914,""y"":-16.153108596801758,""z"":-35.62408447265625,""timestamp"":1588414294076},{""x"":31.090707778930664,""y"":-15.918539047241211,""z"":-35.245361328125,""timestamp"":1588414344395},{""x"":30.96401023864746,""y"":-15.873424530029297,""z"":-35.649749755859375,""timestamp"":1588414394720},{""x"":30.98093605041504,""y"":-15.919719696044922,""z"":-36.30181884765625,""timestamp"":1588414445031},{""x"":31.302135467529297,""y"":-15.669422149658203,""z"":-35.82948303222656,""timestamp"":1588414495341},{""x"":31.16522216796875,""y"":-16.057003021240234,""z"":-35.8358154296875,""timestamp"":1588414545670},{""x"":31.101856231689453,""y"":-15.532207489013672,""z"":-35.752586364746094,""timestamp"":1588414595985},{""x"":31.467771530151367,""y"":-16.45595359802246,""z"":-35.88365936279297,""timestamp"":1588414646289},{""x"":31.22051429748535,""y"":-15.855661392211914,""z"":-36.1585693359375,""timestamp"":1588414696602},{""x"":31.56662940979004,""y"":-16.31602668762207,""z"":-36.29974365234375,""timestamp"":1588414746930},{""x"":31.18305015563965,""y"":-16.257770538330078,""z"":-36.19493865966797,""timestamp"":1588414797238},{""x"":31.38979721069336,""y"":-15.869497299194336,""z"":-35.89295959472656,""timestamp"":1588414847562},{""x"":31.316211700439453,""y"":-15.530294418334961,""z"":-36.30865478515625,""timestamp"":1588414897880},{""x"":30.91192054748535,""y"":-16.352867126464844,""z"":-35.268272399902344,""timestamp"":1588414948198},{""x"":31.375812530517578,""y"":-15.807861328125,""z"":-36.171669006347656,""timestamp"":1588414998509},{""x"":31.962923049926758,""y"":-15.168851852416992,""z"":-36.141456604003906,""timestamp"":1588415048827},{""x"":32.7541618347168,""y"":-15.17684555053711,""z"":-35.48052215576172,""timestamp"":1588415099141},{""x"":32.66035079956055,""y"":-15.579492568969727,""z"":-35.61066436767578,""timestamp"":1588415149458},{""x"":32.085079193115234,""y"":-14.920377731323242,""z"":-35.454254150390625,""timestamp"":1588415199777},{""x"":32.73699188232422,""y"":-14.991544723510742,""z"":-35.26123809814453,""timestamp"":1588415250093},{""x"":32.382442474365234,""y"":-14.917608261108398,""z"":-35.41968536376953,""timestamp"":1588415300402},{""x"":32.6612434387207,""y"":-14.714042663574219,""z"":-34.808753967285156,""timestamp"":1588415350724},{""x"":32.67103576660156,""y"":-15.316694259643555,""z"":-35.529762268066406,""timestamp"":1588415401045},{""x"":32.116477966308594,""y"":-15.012884140014648,""z"":-36.029136657714844,""timestamp"":1588415451359},{""x"":32.47699737548828,""y"":-14.545869827270508,""z"":-35.398529052734375,""timestamp"":1588415501682},{""x"":32.584205627441406,""y"":-14.993099212646484,""z"":-36.16304016113281,""timestamp"":1588415552001},{""x"":32.19566345214844,""y"":-14.81112289428711,""z"":-35.03266143798828,""timestamp"":1588415602322},{""x"":31.734764099121094,""y"":-15.217241287231445,""z"":-35.52405548095703,""timestamp"":1588415652628},{""x"":33.15986633300781,""y"":-15.297021865844727,""z"":-37.7271728515625,""timestamp"":1588415702953},{""x"":29.32909393310547,""y"":14.613388061523438,""z"":-39.471923828125,""timestamp"":1588415753259},{""x"":29.19544219970703,""y"":15.276500701904297,""z"":-40.055084228515625,""timestamp"":1588415803565},{""x"":28.47340965270996,""y"":14.698341369628906,""z"":-38.0999755859375,""timestamp"":1588415853867},{""x"":29.068220138549805,""y"":14.858322143554688,""z"":-38.61859130859375,""timestamp"":1588415904174},{""x"":26.11041259765625,""y"":10.723255157470703,""z"":-20.30066680908203,""timestamp"":1588415954466},{""x"":26.297706604003906,""y"":10.86385726928711,""z"":-21.739830017089844,""timestamp"":1588416015404},{""x"":20.013809204101562,""y"":4.622589111328125,""z"":-34.64476776123047,""timestamp"":1588416101960},{""x"":21.0351505279541,""y"":-4.114194869995117,""z"":-36.97352600097656,""timestamp"":1588416152246},{""x"":21.163021087646484,""y"":-4.097576141357422,""z"":-37.142494201660156,""timestamp"":1588416202538},{""x"":21.29568862915039,""y"":-3.4318580627441406,""z"":-36.88457489013672,""timestamp"":1588416252838},{""x"":21.087635040283203,""y"":-4.113517761230469,""z"":-35.731536865234375,""timestamp"":1588416303140},{""x"":21.403427124023438,""y"":-4.079875946044922,""z"":-37.07737731933594,""timestamp"":1588416353448},{""x"":21.382801055908203,""y"":-3.8635692596435547,""z"":-35.94225311279297,""timestamp"":1588416403749},{""x"":20.29475975036621,""y"":-6.222526550292969,""z"":-36.635498046875,""timestamp"":1588416454069},{""x"":21.097827911376953,""y"":-4.561748504638672,""z"":-37.133399963378906,""timestamp"":1588416504381},{""x"":20.310977935791016,""y"":-2.992830276489258,""z"":-36.34771728515625,""timestamp"":1588416554701},{""x"":26.041868209838867,""y"":-4.221691131591797,""z"":-34.06073760986328,""timestamp"":1588416605018},{""x"":25.343236923217773,""y"":-4.104442596435547,""z"":-33.16755676269531,""timestamp"":1588416655331},{""x"":25.6159725189209,""y"":-4.271944046020508,""z"":-33.616371154785156,""timestamp"":1588416705654},{""x"":25.861473083496094,""y"":-3.744152069091797,""z"":-32.70707702636719,""timestamp"":1588416755975},{""x"":26.230632781982422,""y"":-3.756196975708008,""z"":-32.90460205078125,""timestamp"":1588416806304},{""x"":26.478591918945312,""y"":-4.001310348510742,""z"":-34.1304931640625,""timestamp"":1588416856627},{""x"":26.393444061279297,""y"":-4.171974182128906,""z"":-33.466339111328125,""timestamp"":1588416906940},{""x"":26.432594299316406,""y"":-4.047908782958984,""z"":-32.92127990722656,""timestamp"":1588416957283},{""x"":26.048677444458008,""y"":-4.051418304443359,""z"":-32.49137878417969,""timestamp"":1588417007602},{""x"":26.044937133789062,""y"":-3.618864059448242,""z"":-32.95166015625,""timestamp"":1588417057942},{""x"":26.191165924072266,""y"":-3.880250930786133,""z"":-33.3565673828125,""timestamp"":1588417108274},{""x"":25.827682495117188,""y"":-3.4353466033935547,""z"":-32.207176208496094,""timestamp"":1588417158602},{""x"":25.734182357788086,""y"":-3.714458465576172,""z"":-32.87889862060547,""timestamp"":1588417208935},{""x"":26.13224983215332,""y"":-3.6799278259277344,""z"":-33.41687774658203,""timestamp"":1588417259250},{""x"":26.088836669921875,""y"":-3.664844512939453,""z"":-33.199981689453125,""timestamp"":1588417309582},{""x"":25.916454315185547,""y"":-3.666339874267578,""z"":-32.488243103027344,""timestamp"":1588417359918},{""x"":25.915674209594727,""y"":-3.4964332580566406,""z"":-32.874114990234375,""timestamp"":1588417410256},{""x"":25.94756507873535,""y"":-3.6970653533935547,""z"":-33.20203399658203,""timestamp"":1588417460586},{""x"":25.733097076416016,""y"":-3.621753692626953,""z"":-32.89330291748047,""timestamp"":1588417510911},{""x"":26.02989387512207,""y"":-3.402751922607422,""z"":-33.476776123046875,""timestamp"":1588417561233},{""x"":-4.288597106933594,""y"":2.483673095703125,""z"":-12.550582885742188,""timestamp"":1588417611562},{""x"":-3.8852500915527344,""y"":1.97747802734375,""z"":-12.691646575927734,""timestamp"":1588417661879},{""x"":37.37435531616211,""y"":15.154117584228516,""z"":-24.070877075195312,""timestamp"":1588417712193},{""x"":-10.629215240478516,""y"":11.459671020507812,""z"":-42.85163879394531,""timestamp"":1588417762506},{""x"":-49.01023864746094,""y"":-21.554176330566406,""z"":18.812170028686523,""timestamp"":1588417812818},{""x"":-48.777061462402344,""y"":-21.75306510925293,""z"":17.602174758911133,""timestamp"":1588417863123},{""x"":-49.39384460449219,""y"":-21.310596466064453,""z"":18.25200653076172,""timestamp"":1588417918348},{""x"":-49.01043701171875,""y"":-21.600500106811523,""z"":19.04435920715332,""timestamp"":1588417968636},{""x"":-49.311309814453125,""y"":-21.850250244140625,""z"":20.946359634399414,""timestamp"":1588418018926},{""x"":-50.03755187988281,""y"":-22.567882537841797,""z"":20.448041915893555,""timestamp"":1588418069225},{""x"":-49.47925567626953,""y"":-22.237998962402344,""z"":21.74654197692871,""timestamp"":1588418119527},{""x"":-49.68310546875,""y"":-22.734479904174805,""z"":20.977766036987305,""timestamp"":1588418169831},{""x"":-49.63313293457031,""y"":-22.363067626953125,""z"":21.61907196044922,""timestamp"":1588418220134},{""x"":-50.608009338378906,""y"":-21.383220672607422,""z"":21.4798641204834,""timestamp"":1588418270454},{""x"":-50.951866149902344,""y"":-21.03104019165039,""z"":21.3404483795166,""timestamp"":1588418320763},{""x"":-50.62835693359375,""y"":-19.82268524169922,""z"":21.855510711669922,""timestamp"":1588418371085},{""x"":-50.08917236328125,""y"":-20.00303077697754,""z"":22.263105392456055,""timestamp"":1588418421400},{""x"":-50.95465087890625,""y"":-19.64037322998047,""z"":21.326313018798828,""timestamp"":1588418471718},{""x"":-50.623634338378906,""y"":-20.008174896240234,""z"":21.124011993408203,""timestamp"":1588418522027},{""x"":-50.841827392578125,""y"":-19.87095832824707,""z"":22.31791877746582,""timestamp"":1588418572345},{""x"":-50.13356018066406,""y"":-19.97247314453125,""z"":22.712947845458984,""timestamp"":1588418622662},{""x"":-50.61085510253906,""y"":-20.193321228027344,""z"":22.208093643188477,""timestamp"":1588418672976},{""x"":-50.10009765625,""y"":-19.508447647094727,""z"":23.71207618713379,""timestamp"":1588418723295},{""x"":-50.57221221923828,""y"":-19.853025436401367,""z"":22.11958885192871,""timestamp"":1588418773608},{""x"":-33.258995056152344,""y"":-14.303421020507812,""z"":-6.749748229980469,""timestamp"":1588418823950},{""x"":30.183881759643555,""y"":-2.267108917236328,""z"":-34.282981872558594,""timestamp"":1588418874250},{""x"":29.861522674560547,""y"":-2.779909133911133,""z"":-33.455108642578125,""timestamp"":1588418924580},{""x"":30.53078842163086,""y"":-2.8047218322753906,""z"":-34.3785400390625,""timestamp"":1588418974897},{""x"":29.47096824645996,""y"":-3.1081314086914062,""z"":-34.084381103515625,""timestamp"":1588419025232},{""x"":29.350704193115234,""y"":-3.6809959411621094,""z"":-34.15483856201172,""timestamp"":1588419075566},{""x"":29.508079528808594,""y"":-3.8494796752929688,""z"":-33.99986267089844,""timestamp"":1588419125918},{""x"":29.255992889404297,""y"":-3.063692092895508,""z"":-33.512237548828125,""timestamp"":1588419176253},{""x"":29.490859985351562,""y"":-3.6641769409179688,""z"":-33.765052795410156,""timestamp"":1588419226585},{""x"":29.500991821289062,""y"":-3.3395862579345703,""z"":-33.74546813964844,""timestamp"":1588419276923},{""x"":30.196210861206055,""y"":-3.1787281036376953,""z"":-34.635292053222656,""timestamp"":1588419327252},{""x"":29.87530517578125,""y"":-3.4444751739501953,""z"":-35.13885498046875,""timestamp"":1588419377571},{""x"":29.638338088989258,""y"":-3.8020591735839844,""z"":-34.9908447265625,""timestamp"":1588419427924},{""x"":29.584468841552734,""y"":-3.045307159423828,""z"":-34.361572265625,""timestamp"":1588419478269},{""x"":29.622032165527344,""y"":-2.9829673767089844,""z"":-33.1190185546875,""timestamp"":1588419528614},{""x"":29.630077362060547,""y"":-3.353900909423828,""z"":-34.16307830810547,""timestamp"":1588419578932},{""x"":29.282062530517578,""y"":-3.2023448944091797,""z"":-32.334327697753906,""timestamp"":1588419629291},{""x"":29.633155822753906,""y"":-3.354005813598633,""z"":-35.07854461669922,""timestamp"":1588419679611},{""x"":28.265918731689453,""y"":-1.2493476867675781,""z"":-32.1673583984375,""timestamp"":1588419729948},{""x"":29.103370666503906,""y"":-1.8600082397460938,""z"":-34.632118225097656,""timestamp"":1588419780280},{""x"":28.491762161254883,""y"":-1.9119224548339844,""z"":-33.724456787109375,""timestamp"":1588419830636},{""x"":28.650100708007812,""y"":-2.0649986267089844,""z"":-33.91065216064453,""timestamp"":1588419880977},{""x"":28.62312889099121,""y"":-2.1888561248779297,""z"":-33.865936279296875,""timestamp"":1588419931301}]" WHERE key = "MAGNETOMETER_DATA"