How to adopt arm_rfft_fast_f32 for ADC

[ddB0515]

Hi

I have tried and works great with I2S but how to adopt code to work on analog mic with ADC (10/12bit)
As array will be real numbers from 0-1023/0-2047 so this will not be quite same

Any tips how to adopt code to work with ADC? Thanks

[YetAnotherElectronicsChannel]

Are you asking now explicit about the arm_rfft_fast_f32 function or in general about interfacing the microphone? I have uploaded a project where I'm showing how to interface a PDM microphone -> I would definitely also recommend using a PDM microphone on a microcontroller if possible because it's quite easy to interface that and to keep it in sync with the I2S interface Am Mo., 5. Juli 2021 um 12:44 Uhr schrieb Dario Budimir < ***@***.***>:

…

Hi I have tried and works great with I2S but how to adopt code to work on analog mic with ADC (10/12bit) As array will be real numbers from 0-1023/0-2047 so this will not be quite same Any tips how to adopt code to work with ADC? Thanks — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#1>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ANPGV2NWFV2OKHE4U24EYPTTWGEIXANCNFSM472PCG6A> .

[ddB0515]

I agree that is easier to use any PDM/I2S but the thing is that I have already design with ICS-40181

I have reading from mic and ADC is working fine, my struggle is how to adopt that readings from ADC with integers into float array (either 10 or 12 bits) and if that values are too high or I need to do something with them to fit into float [-1:1] range 🤔

I'm new to CMSIS DSP so have understanding that I'm still learning :)
Thanks

[YetAnotherElectronicsChannel]

Well the fft function is working on floating-point 32 bit. It doesn't matter if you keep the data between +1 and -1 or if it is scaled to some higher values (from algorithm point of view - both is fine). But the output-data are then also higher or lower values. So I would propose to bring your data into a 16-bit signed integer format (int16_t) -> then check that the data is really centered around the 0 point and then cast it to (float) and run the fft function. Am Mo., 5. Juli 2021 um 13:11 Uhr schrieb Dario Budimir < ***@***.***>:

…

I agree that is easier to use any PDM/I2S but the thing is that I have already design with ICS-40181 <https://3cfeqx1hf82y3xcoull08ihx-wpengine.netdna-ssl.com/wp-content/uploads/2016/04/DS-000028-ICS-40181-v1.3.pdf> I have reading from mic and ADC is working fine, my struggle is how to adopt that readings from ADC with integers into float array (either 10 or 12 bits) and if that values are too high or I need to do something with them to fit into float [-1:1] range 🤔 I'm new to CMSIS DSP so have understanding that I'm still learning :) Thanks — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#1 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ANPGV2LN7WZJUZ7PJNI5JBLTWGHOPANCNFSM472PCG6A> .

[ddB0515]

I have done that and this is how my ftt_in float array looks like (doing sample on 512 for tessting later will increase to 1024)
This is ADC reading from mic in 10bit

fft_in

470.000000, 470.000000, 472.000000, 474.000000, 472.000000, 472.000000, 472.000000, 471.000000, 471.000000, 467.000000, 470.000000, 473.000000, 473.000000, 475.000000, 473.000000, 473.000000, 473.000000, 471.000000, 471.000000, 473.000000, 473.000000, 471.000000, 474.000000, 473.000000, 474.000000, 475.000000, 476.000000, 475.000000, 476.000000, 473.000000, 474.000000, 475.000000, 475.000000, 475.000000, 475.000000, 478.000000, 476.000000, 474.000000, 472.000000, 471.000000, 469.000000, 468.000000, 469.000000, 469.000000, 470.000000, 470.000000, 468.000000, 468.000000, 470.000000, 467.000000, 467.000000, 465.000000, 466.000000, 466.000000, 468.000000, 468.000000, 470.000000, 468.000000, 468.000000, 467.000000, 466.000000, 465.000000, 468.000000, 468.000000, 468.000000, 468.000000, 467.000000, 469.000000, 469.000000, 472.000000, 471.000000, 472.000000, 473.000000, 474.000000, 472.000000, 473.000000, 474.000000, 474.000000, 476.000000, 474.000000, 477.000000, 475.000000, 477.000000, 476.000000, 475.000000, 477.000000, 476.000000, 475.000000, 479.000000, 478.000000, 479.000000, 480.000000, 478.000000, 479.000000, 479.000000, 478.000000, 478.000000, 478.000000, 477.000000, 477.000000, 477.000000, 476.000000, 475.000000, 475.000000, 476.000000, 475.000000, 474.000000, 473.000000, 472.000000, 472.000000, 471.000000, 467.000000, 470.000000, 470.000000, 468.000000, 467.000000, 467.000000, 465.000000, 465.000000, 465.000000, 463.000000, 463.000000, 464.000000, 464.000000, 464.000000, 462.000000, 461.000000, 462.000000, 462.000000, 462.000000, 463.000000, 462.000000, 463.000000, 459.000000, 462.000000, 464.000000, 462.000000, 464.000000, 468.000000, 469.000000, 468.000000, 467.000000, 467.000000, 469.000000, 468.000000, 472.000000, 472.000000, 469.000000, 471.000000, 472.000000, 471.000000, 470.000000, 469.000000, 469.000000, 472.000000, 472.000000, 473.000000, 472.000000, 473.000000, 472.000000, 473.000000, 473.000000, 472.000000, 474.000000, 473.000000, 474.000000, 475.000000, 472.000000, 473.000000, 472.000000, 472.000000, 471.000000, 471.000000, 472.000000, 471.000000, 470.000000, 470.000000, 467.000000, 468.000000, 466.000000, 468.000000, 466.000000, 467.000000, 468.000000, 468.000000, 469.000000, 468.000000, 467.000000, 469.000000, 468.000000, 468.000000, 468.000000, 468.000000, 467.000000, 468.000000, 468.000000, 470.000000, 470.000000, 471.000000, 472.000000, 471.000000, 472.000000, 474.000000, 473.000000, 474.000000, 475.000000, 474.000000, 474.000000, 476.000000, 478.000000, 478.000000, 478.000000, 478.000000, 479.000000, 480.000000, 483.000000, 483.000000, 483.000000, 480.000000, 481.000000, 483.000000, 483.000000, 483.000000, 484.000000, 483.000000, 484.000000, 481.000000, 482.000000, 480.000000, 482.000000, 480.000000, 481.000000, 481.000000, 482.000000, 479.000000, 476.000000, 477.000000, 477.000000, 477.000000, 477.000000, 478.000000, 473.000000, 475.000000, 473.000000, 471.000000, 471.000000, 469.000000, 468.000000, 470.000000, 467.000000, 467.000000, 468.000000, 467.000000, 468.000000, 468.000000, 468.000000, 468.000000, 468.000000, 467.000000, 469.000000, 468.000000, 468.000000, 468.000000, 467.000000, 467.000000, 470.000000, 467.000000, 467.000000, 468.000000, 468.000000, 469.000000, 472.000000, 471.000000, 472.000000, 475.000000, 473.000000, 472.000000, 472.000000, 474.000000, 474.000000, 472.000000, 476.000000, 476.000000, 476.000000, 476.000000, 476.000000, 475.000000, 475.000000, 477.000000, 478.000000, 479.000000, 479.000000, 478.000000, 479.000000, 480.000000, 478.000000, 478.000000, 478.000000, 476.000000, 476.000000, 478.000000, 476.000000, 474.000000, 475.000000, 474.000000, 472.000000, 473.000000, 472.000000, 471.000000, 472.000000, 468.000000, 471.000000, 471.000000, 467.000000, 469.000000, 467.000000, 467.000000, 469.000000, 469.000000, 469.000000, 469.000000, 469.000000, 469.000000, 468.000000, 470.000000, 469.000000, 467.000000, 468.000000, 468.000000, 471.000000, 469.000000, 470.000000, 470.000000, 470.000000, 471.000000, 472.000000, 471.000000, 473.000000, 473.000000, 473.000000, 474.000000, 478.000000, 479.000000, 477.000000, 480.000000, 479.000000, 478.000000, 478.000000, 480.000000, 479.000000, 478.000000, 480.000000, 478.000000, 481.000000, 477.000000, 480.000000, 477.000000, 479.000000, 481.000000, 479.000000, 479.000000, 480.000000, 479.000000, 477.000000, 480.000000, 479.000000, 478.000000, 477.000000, 475.000000, 475.000000, 475.000000, 475.000000, 472.000000, 471.000000, 471.000000, 472.000000, 469.000000, 468.000000, 468.000000, 465.000000, 465.000000, 468.000000, 466.000000, 465.000000, 463.000000, 465.000000, 465.000000, 464.000000, 465.000000, 464.000000, 463.000000, 464.000000, 466.000000, 464.000000, 464.000000, 465.000000, 464.000000, 466.000000, 467.000000, 465.000000, 465.000000, 464.000000, 467.000000, 467.000000, 464.000000, 465.000000, 466.000000, 465.000000, 467.000000, 468.000000, 466.000000, 469.000000, 468.000000, 468.000000, 470.000000, 470.000000, 469.000000, 472.000000, 472.000000, 471.000000, 473.000000, 473.000000, 474.000000, 473.000000, 472.000000, 474.000000, 473.000000, 471.000000, 474.000000, 473.000000, 473.000000, 473.000000, 473.000000, 473.000000, 473.000000, 474.000000, 475.000000, 472.000000, 473.000000, 473.000000, 470.000000, 471.000000, 468.000000, 471.000000, 468.000000, 468.000000, 466.000000, 467.000000, 468.000000, 466.000000, 467.000000, 466.000000, 466.000000, 466.000000, 466.000000, 467.000000, 465.000000, 468.000000, 467.000000, 469.000000, 466.000000, 468.000000, 466.000000, 465.000000, 466.000000, 468.000000, 467.000000, 468.000000, 468.000000, 470.000000, 469.000000, 471.000000, 469.000000, 468.000000, 470.000000, 471.000000, 472.000000, 475.000000, 474.000000, 473.000000, 473.000000, 472.000000, 476.000000, 473.000000, 474.000000, 471.000000, 474.000000, 476.000000, 473.000000, 476.000000, 473.000000, 475.000000, 475.000000, 476.000000, 473.000000, 474.000000, 474.000000, 473.000000, 473.000000, 473.000000, 472.000000, 472.000000, 472.000000, 473.000000, 470.000000, 472.000000, 471.000000, 469.000000, 471.000000, 470.000000, 470.000000, 470.000000

fft_out

241477.000000, -9.000000, -330.333069, 0.126338, 409.990234, -220.075714, 85.746460, -264.284637, -183.409668, 557.786255, 206.341339, -77.749763, 253.050873, -182.443726, 653.942505, -94.247086, -1157.746582, 144.558182, -101.924065, 89.304222, -71.877716, 34.651730, -76.484581, -22.254322, -20.970310, -42.833496, 2.441109, 42.311226, 82.606415, 34.081078, 5.066083, 39.226070, -15.304334, -79.047127, 5.236312, -15.419328, 60.370472, -32.509136, 19.258598, -13.130545, -67.404213, -35.416744, 63.287926, -30.263626, 27.630713, -12.828226, -118.801834, -15.899589, -18.511959, -7.213923, -36.565529, 14.339331, -3.346172, -44.513268, 10.980262, 17.463398, 96.122849, 20.899891, -12.038475, 10.986976, 28.295502, -22.670187, -31.881645, 13.566383, 9.786232, 1.540323, 25.586216, 1.422408, 10.175123, -27.425018, -2.734988, 25.159910, 18.203012, -22.586700, -21.338650, -9.045558, -2.518400, 11.220129, -10.219503, -39.474640, 5.312395, -3.215765, -0.461587, 6.883627, -11.643735, -15.820237, 9.878674, 16.150364, 29.179516, -31.703512, 56.525608, -67.519073, 18.987604, -44.784054, 0.878578, -59.492203, -10.597196, -30.830914, 2.848860, -14.478133, -56.599220, -4.971299, -20.890045, -7.701530, -49.287373, 45.590961, -29.971537, -33.147213, -43.630196, 22.241673, 7.544433, 5.552797, 25.778742, -19.054441, -10.348200, -13.533422, 17.854366, -7.165718, 9.547415, -11.877698, -7.546543, -55.065414, -58.349220, 54.214874, 12.259879, 19.816189, -14.745012, 4.213924, -3.292893, 0.121320, -52.475658, 2.054917, -1.222340, 0.904984, 1.910348, -4.894499, -30.574787, 12.934574, -16.677517, 1.637878, -9.223944, 41.929123, 17.978239, 14.627471, -15.528014, 14.355435, 33.572586, 8.109227, 16.207781, -1.334169, 18.309895, -0.901055, -1.194544, -0.043232, -25.949062, 22.374413, -5.978103, 10.542391, 1.568721, -2.690471, -6.900041, 17.930084, 18.626158, 0.681210, -0.678888, -4.172308, 14.792398, -7.312870, -6.135071, -33.288311, 15.408604, 13.032215, 9.821947, -33.861599, 10.905316, -4.151483, 3.737005, 30.358086, -13.242620, -36.748188, 23.908115, 34.724674, -26.808950, 27.908333, -23.670664, 12.384932, -18.378246, -38.657654, -18.790497, 8.378227, 1.234499, 17.945065, -27.912498, -24.074886, 0.307587, -39.446396, 8.335053, -3.213042, 24.878489, 6.724213, -12.642973, -29.411940, -24.821707, -23.992998, -0.566891, 22.574404, 31.801762, -8.109469, -8.300289, 1.268486, 1.828162, -4.687826, 9.976644, 2.335133, -4.538285, 2.339061, -7.079181, 3.802193, -16.949772, 10.196293, -25.905762, -5.544394, -38.671471, 11.573568, 16.053810, 14.624264, -3.047248, 27.159925, 4.373485, 2.521213, -31.780680, -9.211993, -8.700058, 8.569246, -10.738739, -10.649546, 5.613060, -12.621674, -9.591280, -11.234501, 5.590773, -3.578451, -4.816828, 13.601073, -3.407594, -11.566238, 0.701492, 19.440632, -40.641590, 11.224906, 2.278223, 17.811922, 19.538595, 21.885925, -5.706879, 36.625992, -2.000000, -7.000000, 7.081514, 10.754768, 11.485417, 4.747947, -4.965734, -1.634805, 4.115975, 23.507645, 19.072443, -23.988777, 6.393785, -12.759054, -4.742849, -9.099511, 9.869234, 39.831978, 10.988258, -14.426314, -7.081445, 0.020805, -29.932365, -1.686282, 26.180809, -18.803980, 24.996130, 1.841510, 6.857337, -4.391087, -22.926512, 20.819296, -11.781922, 7.750675, 19.058804, -4.984441, -26.858185, -1.532652, 10.498143, 7.424350, -1.102254, -16.570822, 18.564194, -18.543835, 4.394023, -4.131880, -18.194105, 7.943795, 0.535706, -52.458172, 26.967777, 1.797380, -9.054066, 60.941048, 0.064077, -9.592941, 5.084642, 3.463546, 2.766801, -5.006810, 9.077312, 7.094713, 27.669853, -17.583500, 23.770363, 16.552532, -7.417204, -20.313572, 32.879181, 33.415390, 27.655357, -3.564717, 18.057095, -0.137091, -11.648455, -5.068604, -10.268806, -2.841759, -7.636061, 25.759106, -5.110614, 5.515307, 9.279254, 14.144439, -32.130257, -11.748731, -20.641331, 1.338411, -6.066973, 6.982371, 6.791955, -14.104572, 15.669457, 8.663827, -26.524149, 19.377712, -1.380289, -27.057999, -13.815514, 28.300991, -8.014494, -9.450855, 13.039891, 48.415417, -1.370108, 7.711626, -23.837589, 30.384647, 29.533937, -12.755972, 23.465544, -5.759638, 12.581762, 27.437855, -24.877668, 47.335785, 23.382019, -34.380875, 9.553640, -7.189495, -2.241066, -9.694958, -4.424084, 29.446413, 11.074640, 27.424997, 7.845849, -1.165291, -4.707107, 4.121320, 7.888013, -16.952454, 3.937343, -7.970085, -27.242455, 3.508614, -5.593227, 7.143744, -3.363115, 17.980404, -3.323717, -14.994774, -1.385641, -47.589966, -9.346849, 13.626749, 15.208145, -32.374512, 22.372334, 6.525711, -7.329649, 15.074791, 21.005917, 3.713219, 9.929501, -14.801415, -2.125643, -21.864773, 20.686218, 5.743115, -25.607756, -5.108315, -15.388357, 3.430007, 5.032212, 0.192894, -29.206804, -19.205185, -35.338669, -23.788736, -0.570679, -10.689383, -10.132526, -25.896599, 12.872835, -9.244177, 8.159772, 5.308179, 1.270624, -20.174612, -11.476772, -12.450027, 15.223518, -12.410548, -22.157724, -4.431126, -0.361061, -25.473150, 37.879845, -16.698486, 15.218900, 16.387028, 14.355904, 6.167739, 2.230049, 9.831980, -5.306286, 19.422945, -44.452538, 11.731730, -6.190598, 6.327118, 3.388226, 14.248632, -0.989607, 7.077910, -13.820879, -15.143354, 19.863382, 17.916451, -6.797981, 6.836869, -30.825392, -15.638388, 11.547447, 11.920635, -2.668600, 9.225334, 31.724865, -38.859692, 25.694592, -25.732643, 26.586941, -7.255367, -16.482269, -15.210036, 1.230034, 2.402262, -7.756817, -0.278358, 16.771828, 27.171396, 4.892245, 5.316366, 1.126106, 26.473618, -7.489452, -2.023205, -10.807770, 18.401638, 3.115601, -18.942368, -18.265228, 2.775249, 8.572876, -2.422504, 11.029152, -6.948103, -0.855873, 28.566572, 3.651028, 11.335864, -13.009262, 11.679359, 3.702942, 38.875271

freqpoint

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 18623160, 1073750016, 201337536, 1073750016, 536881864, 536881864, 169220193, 536871704, 1, 536880120, 980, 1681427419, 536881896, 60523, 176179525, 536871704, 1214905700, 93536, 536881920, 60553, 167772217, 536871704, 536881936, 18235, 536882044, 10, 536881952, 8989, 536882332, 10, 0, 536882332, 536881984, 13417, 0, 536872056, 32, 536881992, 0, 536880332, 32, 0, 0, 536880332, 536880320, 536871088, 536882032, 44287, 0, 536871088, 0, 0, 536880332, 0, 32, 0, 536882364, 92388, 536882332, 8957, 536882088, 536871088, 536882096, 71827, 0, 536870976, 536882112, 536882112, 0, 536870976, 536882128, 87669, 536871080, 536870976, 0, 0, 536882152, 0, 0, 536872056, 32, 536882168, 0, 536880332, 32, 0, 0, 536880332, 536880320, 536870976, 536882208, 44291, 0, 536870976, 0, 0, 536880332, 0, 32, 0, 536880332, 0, 536882256, 66045, 536882264, 536870976, 536882272, 66305, 0, 536870912, 536882288, 26511, 93088, 536871800, 536882320, 0, 536882312, 53895, 93088, 536871800, 93064, 93432, 536882336, 53951, 93088, 536871800

by the look it doesn't seems to be normal but maybe I'm wrong...let me know what do you think

[ddB0515]

also this one is with noise/offset removed

107, 48, 58, 44, 47, 45, 40, 48, 41, 35, 33, 27, 38, 31, 28, 27, 34, 23, 25, 25, 30, 26, 29, 36, 24, 21, 24, 23, 19, 19, 8, 24, 31, 31, 33, 30, 27, 32, 28, 29, 10, 26, 15, 23, 23, 34, 18, 32, 26, 29, 7, 19, 31, 21, 16, 30, 26, 16, 15, 32, 27, 32, 5, 24, 28, 27, 21, 9, 31, 19, 27, 26, 27, 30, 13, 21, 27, 16, 15, 19, 30, 19, 30, 23, 26, 26, 21, 23, 19, 28, 24, 25, 26, 31, 33, 21, 21, 19, 20, 18, 29, 21, 26, 16, 28, 26, 31, 18, 22, 29, 26, 26, 18, 16, 24, 27, 26, 28, 22, 27, 26, 34, 21, 26, 34, 24, 34, 30, 0, 1, 18623160, 1073750016, 201337536, 1073750016, 536881864, 536881864, 169220193, 536871704, 1, 536880120, 980, 1681427419, 536881896, 60519, 176179525, 536871704, 1214905700, 93536, 536881920, 60549, 167772217, 536871704, 536881936, 18231, 536882044, 10, 536881952, 8985, 536882332, 10, 0, 536882332, 536881984, 13413, 0, 536872056, 32, 536881992, 0, 536880332, 32, 0, 0, 536880332, 536880320, 536871088, 536882032, 44287, 0, 536871088, 0, 0, 536880332, 0, 32, 0, 536882364, 92388, 536882332, 8953, 536882088, 536871088, 536882096, 71827, 0, 536870976, 536882112, 536882112, 0, 536870976, 536882128, 87665, 536871080, 536870976, 0, 0, 536882152, 0, 0, 536872056, 32, 536882168, 0, 536880332, 32, 0, 0, 536880332, 536880320, 536870976, 536882208, 44287, 0, 536870976, 0, 0, 536880332, 0, 32, 0, 536880332, 0, 536882256, 66041, 536882264, 536870976, 536882272, 66301, 0, 536870912, 536882288, 26507, 93088, 536871800, 536882320, 0, 536882312, 53891, 93088, 536871800, 93064, 93432, 536882336, 53947, 93088, 536871800