Du coup j’ai viré l’optocoupleur et j’ai mis un pont diviseur de tension (20kOhm + 5,1kOhm) pour avoir mon 5V compatible avec l’analyseur logique et j’ai refait un scan du BUS de la carte mère.
Voici l'export du signal obtenu sous Saleae Logic 2 (v2.4.6)
Time [s],Channel 0
-0.050000042,1
0.000000000,0
0.000395083,1
0.001249417,0
0.002061125,1
0.002915292,0
0.004143667,1
0.004581125,0
0.004976667,1
0.008330042,0
0.008725250,1
0.009163042,0
0.010391333,1
0.011245375,0
0.012057333,1
0.012494750,0
0.012890333,1
0.013744167,0
0.014139875,1
0.014993542,0
0.015805875,1
0.016659667,0
0.017888458,1
0.018326000,0
0.019971000,1
0.020824833,0
0.022470042,1
0.022907167,0
0.027051583,1
0.027488708,0
0.027884667,1
0.028321958,0
0.029550667,1
0.030404292,0
0.031216583,1
0.032070000,0
0.032882750,1
0.033319542,0
0.035798333,1
0.036651500,0
0.037464375,1
0.037901375,0
0.038713833,1
0.039150958,0
0.039963417,1
0.041233292,0
0.041629417,1
0.042899125,0
0.044961417,1
0.045814458,0
0.046627500,1
0.047064250,0
0.049543083,1
0.050396458,0
0.050792583,1
0.051229375,0
0.051625625,1
0.052062333,0
0.052458667,1
0.054144667,0
0.054541125,1
0.054977542,0
0.055374167,1
0.055810583,0
0.056207250,1
0.056643750,0
0.057040250,1
0.057477042,0
0.058289792,1
0.058726792,0
0.059122708,1
0.059559750,0
0.059955792,1
0.060392625,0
0.060788833,1
0.061642042,0
0.062871375,1
0.063307875,0
0.063704375,1
0.064140792,0
0.064953833,1
0.065806708,0
0.066203458,1
0.067473208,0
0.067869458,1
0.068723000,0
0.070368500,1
0.070805250,0
0.071201500,1
0.071638167,0
0.072867542,1
0.073304000,0
0.073700583,1
0.074553417,0
0.074950083,1
0.075386333,0
0.075783125,1
0.077052750,0
0.077449125,1
0.077886042,0
0.082030750,1
0.082467250,0
0.082863750,1
0.083300167,0
0.083696750,1
0.084549500,0
0.084946250,1
0.085799042,0
0.086195833,1
0.087048875,0
0.091193917,1
0.091630333,0
0.095775542,1
0.096211625,0
0.100357083,1
0.100793542,0
0.104938667,1
0.105374625,0
0.106188208,1
0.107457625,0
0.107854250,1
0.108707500,0
0.109103750,1
0.109956875,0
0.114101833,1
0.114537875,0
0.115351417,1
0.115787375,0
0.118266958,1
0.119120125,0
0.123265083,1
0.123701042,0
0.127846667,1
0.128283125,0
0.129929167,1
0.131614958,0
0.132428250,1
0.132864333,0
0.134510708,1
0.136196250,0
0.137009833,1
0.137446208,0
0.138259333,1
0.138696000,0
0.139092375,1
0.140778417,0
0.141174917,1
0.142027792,0
0.146173042,1
0.146609167,0
0.147006042,1
0.147859042,0
0.148672125,1
0.149525167,0
0.149921583,1
0.151191042,0
0.151587583,1
0.152023958,0
0.152837167,1
0.153689875,0
0.154086667,1
0.154522750,0
0.155336208,1
0.155772208,0
0.157835250,1
0.158688542,0
0.159917833,1
0.160354375,0
0.164499375,1
0.164935292,0
0.165332417,1
0.166601583,0
0.168247917,1
0.168684625,0
0.169081000,1
0.169517542,0
0.169914000,1
0.171183458,0
0.172829458,1
0.173265708,0
0.173662583,1
0.174098625,0
0.174495625,1
0.174931583,0
0.175328583,1
0.175764583,0
0.178244167,1
0.178680833,0
0.179077167,1
0.180346708,0
0.180743250,1
0.181179667,0
0.182825792,1
0.183261875,0
0.184075250,1
0.184511292,0
0.185324833,1
0.186177292,0
0.186990500,1
0.187843875,0
0.189073417,1
0.189926458,0
0.190322958,1
0.192425333,0
0.193654958,1
0.195757083,0
0.196154042,1
0.197006958,0
0.197403625,1
0.198256875,0
0.199486125,1
0.201588708,0
0.202401625,1
0.202838083,0
0.205317292,1
0.206169875,0
0.210315292,1
0.210751833,0
0.214896917,1
0.215332833,0
0.219478500,1
0.219915000,0
0.224060125,1
0.224496000,0
0.224893000,1
0.225745417,0
0.226559083,1
0.228245250,0
0.228641667,1
0.229078250,0
0.229474667,1
0.229911167,0
0.230307750,1
0.233659500,0
0.234056292,1
0.234492417,0
0.235722292,1
0.236158375,0
0.236555375,1
0.236991583,0
0.237388333,1
0.238241667,0
0.238637917,1
0.239491083,0
0.239887417,1
0.240323958,0
0.241969958,1
0.242822750,0
0.246968042,1
0.247404417,0
0.251549625,1
0.251985875,0
0.256131208,1
0.256567250,0
0.260712833,1
0.261149083,0
0.262795417,1
0.264064333,0
0.264461375,1
0.264897167,0
0.265294417,1
0.265730208,0
0.266127500,1
0.267396750,0
0.267793500,1
0.270312542,0
0.270709042,1
0.271145458,0
0.271958542,1
0.272394833,0
0.272791583,1
0.273227750,0
0.273624708,1
0.274060708,0
0.274457667,1
0.274893625,0
0.279039250,1
0.279475750,0
0.283620792,1
0.284056792,0
0.288202333,1
0.288638917,0
0.292783958,1
0.293219958,0
0.297365583,1
0.297801833,0
0.298615083,1
0.299051542,0
0.300697667,1
0.301133792,0
0.301947250,1
0.302383167,0
0.306528708,1
0.306964708,0
0.311110333,1
0.311546417,0
0.315691917,1
0.316127542,0
0.320273542,1
0.320709625,0
0.324855167,1
0.325290500,0
0.329436708,1
0.329872750,0
0.334018292,1
0.334453792,0
0.338599875,1
0.339036042,0
0.343181500,1
0.343616958,0
0.344430958,1
0.344866375,0
0.345680542,1
0.346532625,0
0.347346583,1
0.348199250,0
0.348596125,1
0.349032292,0
0.349429125,1
0.349865208,0
0.351511708,1
0.500000042,1
Avec pour paramétrage :