En échangeant
Serial.println(x, y);
par
Serial.print(x,5);
Serial.print(",");
Serial.println(y,5);
dans le code que je t'ai proposé, j'obtiens
0.00001,0.05000
0.00002,0.05000
0.00002,0.05000
0.00003,0.05000
0.00003,0.05000
0.00004,0.05000
0.00005,0.05000
0.00006,0.05000
0.00008,0.05000
0.00010,0.05001
0.00013,0.05001
0.00016,0.05001
0.00020,0.05001
0.00025,0.05002
0.00032,0.05002
0.00040,0.05002
0.00050,0.05003
0.00063,0.05004
0.00079,0.05005
0.00100,0.05006
0.00126,0.05008
0.00158,0.05010
0.00200,0.05012
0.00251,0.05015
0.00316,0.05019
0.00398,0.05024
0.00501,0.05031
0.00631,0.05038
0.00794,0.05048
0.01000,0.05061
0.01259,0.05077
0.01585,0.05097
0.01995,0.05122
0.02512,0.05153
0.03162,0.05193
0.03981,0.05243
0.05012,0.05306
0.06310,0.05385
0.07943,0.05485
0.10000,0.05610
0.12589,0.05768
0.15849,0.05967
0.19953,0.06217
0.25119,0.06532
0.31623,0.06929
0.39811,0.07428
0.50119,0.08057
0.63096,0.08849
0.79433,0.09845
1.00000,0.11100
1.25893,0.12679
1.58489,0.14668
1.99526,0.17171
2.51189,0.20323
3.16228,0.24290
3.98107,0.29285
5.01187,0.35572
6.30957,0.43488
7.94328,0.53454
10.00000,0.66000
12.58925,0.81794
15.84893,1.01679
19.95262,1.26711
25.11886,1.58225
31.62278,1.97899
39.81072,2.47845
50.11872,3.10724
63.09573,3.89884
79.43282,4.89540
100.00000,6.15000
125.89254,7.72944
158.48932,9.57031
199.52623,11.06406
251.18864,12.94457
316.22775,15.31199
398.10718,18.29240
501.18723,22.04452
630.95734,26.76815
794.32825,32.71485
1000.00000,40.20130
1258.92542,49.62618
1584.89319,61.49141
1995.26233,76.42885
2511.88647,95.23397
3162.27759,118.90821
3981.07178,148.71233
5011.87256,186.23347
6309.57324,233.46977
7943.28223,292.93680
10000.00000,367.80130
12589.25391,462.05017
15848.93164,580.70245
19952.62305,730.07678
25118.86523,918.12805
31622.77734,1154.87048
39810.71875,1452.91150
50118.72266,1828.12292
63095.73438,2300.48608
79432.82031,2895.15601