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Hello Paul,
I need to know about the Micro SD card adaptor. I'm trying to make my own PCB for one of the project. So i'm using Teensy 3.2 as well as Micro SD card. So my design will be same like...

When im recording sound files to SD card through Teensy it will give some default create date and time. But i need to update exact date and time when creating wave files. Also currently i have access...

Ops my bad. I thought my usb power is not good

When i connect my LiPo battery to charger and when i plugged to USB Yellow and Red both lights up. Cant figure out the issue

12062

Thanks alot for the information.
One more thing when teensy is connected to usb, LiPo will charge right? So at the same time can i program teensy??? When programming teensy nothing going to affect...

If im going to connect STBC08 with Teensy 3.2,
1.Cut Vin and VUSB trace
2.Solder VIN, GND and VUSB pins of the STBC08 with Teensy 3.2.
Am i correct ???(Not sure whether VUSB pin of Teensy and...

Hello Michael
Could you please post some picture of the current way you have connected STBC08 to Teensy? I already bough STBC08 and want to see how it looks like before connecting to teensy

Paul i able achieve that. But it store as .raw file. Any idea how to convert it into .wav and store it on the SD card?

I have done the same thing with Audacity. Imported as raw audio and export it as wav. But instead of using audacity i prefer recording .wav files.
I will look at neutronned's thread

Any idea how to record mono channel using ADC ? Not from using Audio shield. Also anyone have experience recording with .wav header extension ?

Now it records something. But when i import .raw file into audacity it has lot of noise. I only need to record with mono channel. Also is that possible to add WAV header ? I couldn't find any forum...

Hello everyone

I'm using Teensy 3.2 with MicroSD adapter + AGC Microphone (Neutronned) for audio recording. I need to record .wav files instead of .raw files. Anyone have experience with...

Derek Could you please explain about the new interpolation method your doing Whittaker (cardinal) interpolation ? Is that only for report magnitude of the lines or is that for frequency...

Good points. Anyway could you please tell me how to take the magnitude of the fft bins in dB. (Bin maximum amplitude is 1)

But i read somewhere by averaging complex spectrum can avoid noises. This is going to be a DSP problem then. My approach is wrong. Are you sure about that?? :eek:

Can someone suggest better way to do this.

The main reason why i asked about how to extract complex value of a bin is because i'm trying to make a function which does FFT Averaging.
Currently doing a project to analyze environment signals...

This is not my own code. Its from Paul's "analyze_fft1024.cpp"


uint32_t tmp = *((uint32_t *)buffer + i); // real & imag

I tried to do modifications after above code. Since in library after...

MichaelMeissner
It should be like this right ???

union u_type{

uint32_t num;
uint16_t buf[2];

}tp;

Ohhh mistake
Here we go



analyze_fft1024.cpp

/* Audio Library for Teensy 3.X
* Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
*

Maybe this what your saying
Check this out

Ok check this out whether im correct or not

analyze_fft1024.cpp

for (int i=0; i < 512; i++) {
uint32_t tmp = *((uint32_t *)buffer + i); // real & imag
//uint32_t magsq =...

I tried to edit the code and print the values. But i don't understand exactly what these values are

analyze_fft1024.cpp

for (int i=0; i < 512; i++) {
uint32_t tmp = *((uint32_t *)buffer +...

I'm bit confusing how this pointers work. If I print "tmp" vatiable it should display the complex value of the particular bin right? Or else is there any proper access method? Since this is pointer...

You mean "tmp" value will return complex value of the particular bin? But it's a pointer right?
Anyway "magsq" is not return complex value for sure.

Any idea how to access the complex value of a bin???
Something like in MATLAB fft() output?? (not abs(fft))

Somebody please tell me how to access the FFT bin complex value?

In Teensy Audio library "analyze_fft1024.cpp",


for (int i=0; i < 512; i++) {
uint32_t tmp = *((uint32_t *)buffer + i); //...

Publish it soon. Anyway i have to do more experiments with species and recordings. Actually at research labs we'r capturing wing beat sound by trapping mosquito's inside a cage. By using Doppler...

I have done one of my IoT project by using ESP8266 12E node mcu module. But since i need to combine that with Teensy 3.2 i thought to use this add-on. But im not quite sure whether all the libraries...

Impressive. Keep remember all this recordings were made at noisy background.
Here i attached another sample file. Its a different species .wav file. Can check both of .wav files have the same...

Can you share the link from where I can buy 3.2 add on?

Is this board available on Tindie?
I only could find the add-on for Teensy 3.1 in the below link
https://www.tindie.com/products/onehorse/esp8266-add-on-for-teensy-31/

But not the add-on for...

Yes im using FFT1024 for further analysis of samples. But rather than that thought about other mechanisms something like PLL for real time capturing frequencies. Without high end of processing.

The main reason im using PLL is to identify the presence of a species and start to record when PLL get lock.(lock in the sense just trigger. No need to keep lock for a long time) Once I have done...

Is this board still available ???

Lol. Sure. Im searching the most efficient and correct algorithm which give correct frequencies. Otherwise results were wrong and im in a trouble :D

I'm trying to analyze the different type mosquito species wing beat tones. Trying to figure out is there any pattern.

Check out the below .wav which has the same buzz with louder sound level. It should give the correct fundamental. So some how Mid level and low level sound should compare with the Louder .wav
Also...

I have a MATLAB code which i use to analyze the .wav files. Simply it will give the peaks by analyzing the spectrogram of the .wav file. According to that MATLAB code,

FE55M.wav has fundamental...

Dave FE55M.wav fundamental is quite correct. Both of the .wav files are same buzz but with two different sound levels. So FE55LW.wav fundamental also should come around the same as FE55M.wav. I know...

This are some of the results. I can't understand the pattern. But seems like its trying to give some valuable information


32767 , 0
31586 , -3782
23760 , -3104
13998 , -2090
6238 , -1419...

Great job. Thanks alot Derek. I have gone through with all your codes and read the Analog PLL design document as well.
You have done a great effort on writing comments. It will explain well about...

I prefer brickwall filtering with Teensy 3.2. I know it cannot do something like Teensy 3.6. But suggest what would be the best filtering mechanism( brickwall filtering) can achieve using Teensy 3.2 ?

Yes. Should start to write a code. Anyway is their proper document that explain how FFT/Convolution algorithm works?

Please somebody in this thread make some FFT/Convolution block for Teensy 3.2. I know teensy 3.2 has a fixed point. But i hope by using teensy 3.2 can achieve upto some extent right? It will be much...

Is that possible to do Fast Convolution filtering with Fixed point devices something like Teensy 3.2 ?? Maybe one of you guys can modify the code for Teensy 3.2

Derek Good explanation as always.
So "uint32_t magsq" is that output value similar to MATLAB "y"(y=fft(x)) complex vector one element? I need to know from where each bin complex value can be find?...

Somebody please tell me in Teensy Audio library "analyze_fft1024.cpp", What is the output of the below lines?


for (int i=0; i < 512; i++) {
uint32_t tmp = *((uint32_t *)buffer + i); // real...

Great work.
Derek I don't understand deeply what you have explained. Some how I guess software PLL can be use with microphone input signal with good sensitivity right.
I never had used software...

Derek

Is that possible to detect certain frequencies from adc input signals(Microphone signals) ?
Something like if i want to lock frequency 450Hz and need a capture range of 400Hz-500Hz...