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There is no need for nanosecond resolution. The PPS from a GPS receiver will provide 10usec resolution for annabsolute time stamp. This is enough to triangulate the sound source with multiple mics. Any wheater proof mic with a wind ‘hat’ will do. But you will need a mic preamp and ADC and teensy...

pictures, or it didnt happen ;-)

If you put 5V on pin4 of the midi_in, does pin 6 of the opto go to 0V? If you put 0V on pin4 of the midi_in, does pin 6 of the opto go to 3.3V? If yes, then at least your opto does work. In that last photo, I still see a 10K from pin 5 to gnd. Pin5 should go directly to GND. pin7 goes , via...

If you put 5V on pin4 of the midi_in, does pin 6 of the opto go to 0V? If you put 0V on pin4 of the midi_in, does pin 6 of the opto go to 3.3V? If yes, then at least your opto does work.

The signal will be too fast. But if you put 5v DC at the opto coupler input, tell us what you see at the ouput. And if you gnd the input?

One more thing you could try, is connect the midi signals direct, no opto coupler.

Can you measure the DC voltages with the input low and also with input high?

What is the advantage of arm_rfft_fast_f32() over arm_cfft_f32()?

Yep, good catch Paul.

I just checked an old project of mine. My 6N138 opto worked fine with the default 220R as drive limiter and 470R as the receive side.

Thanks for sharing that. Will go through that code with great interest..

Lower that 220R a bit. And try various alternative to that 470R Or just use a faster optocoupler?

yes, if the noise is still present with the ADC grounded (meaning, the input of the ADC shorted to GND, so no signal can reach the ADC, no noise and no EMI), all the noise that you still get is inherent from your data aquisition system, and unrelated to your sensor of signal conditioning...

Incredible!!! A teensy controlling 4185 horsepower ��

Noise (hiss) or EMI (buzzes) ? Is it still there when you ground the input of the mixer?

I think this is were I left the project last time I worked on it. IIRC i got the sending of the data working, but was never able to verify it on a receiving PC. see attached code (it uses the Teensy audio toolbox with the queue object and uses UDP to send data) #include <Arduino.h> #include...

Following&#55357;&#56835;

Hi, Project run low for a while, but I think I got 8 channels working. Will post some code when I get home this weekend. Meanwhile, what is you project about?

Thanks for these efforts, I am following!

when trying to verify teh code I get an error message: Arduino: 1.8.13 (Windows 10), TD: 1.53, Board: "Teensy 4.1, Serial, 600 MHz, Faster, US English" bla bla ..... ^ Basic_I2S_Input_Example_for_T4:214: error: no matching...

I thought that freezing without a Ethernet cable connected is a known issue.

I bought a USB hub with power supply and now the teensy COM port is just there; problem solved. Prolly a USB power issue.

Thanks for the tip. Something like that might be the case, since the CS42448 CODEC draws some significant current and gets hot.

New info: with my CS42448 multi-channel audio CODEC sketch, and the CODEC IC breakout board attached, the COM port disappears. With the CODEC IC board disconnected, the COM port does appear. Some there is definitely some interference with the CS42448 audio breakout board I am using. Do...

I cann't open the Serial Monitor, as no COM port is available. Upon an 15sec reset, and the 2sec Blinking programs is started, I can upload a sketch via Port : " hid#vid16x....... (strange characters)... but still no Teensy port in the Device manager. The hid-port disappears after uploading...

OK, so I did reset the teensy 4.1 by pressing the button 15 sec. I could see a single red led flash, and upon release and 30sec waiting, a 2 sec Blink program runs. Upon compiling and uploading my sketch, the uploading fails as no teensy board is found. The sketch uploads directly after pushing...

OK, good to know and will try that.

Thanks for the fast replies gentlemen. Didn’t try the 15sec reset yet. Furthermore on my other computer, a laptop, a COM port 6 or 7 does appear....and I can use the serial monitor! Will report back as soon as I have some time to test more.

Upon connecting my teensy 4.1 to the USB cable, it wont show up anymore as a COM7 port, not in the win10 Device manager, and not in the Arduino > Tools > Port. My teensy 3.6 and 4.0 show up immediately in both the win10 DeviceManager and in Arduino>tools>Port, with the same cable, same USB...

Very educational, thanks for posting this.

Interesting remarks, thx

There is the Texas Instruments ADS1278, 8 ch , 144kHz, simultanious ADC and the Analog Devices AD7768, 8 ch, 256kHz, simultanious ADC both 24 bit, but not as fast as the ADS8885.

Following!

Looks like a nice DAC. How fast is it?

Maybe place the mutt on top of a mems microphone? as soon as the mutt is being moved this should cause a use contact sound. Trigger the camera from a sound level detector? PDont think you even need an MCU for this

BTW. Using UDP or Serial is almost the same in MATLAB.

Real-time means time-deterministic. You should specify ur max allowed latenctly, which is not the same as saying real-time.

Matlab has UDP data transfer functions. I have gotten beyond 80mbit with matlab.

What bitrate do you need? You can try Ethernet which will give you up to 80..90 mbit per second.

Datasheet has no noise data (except for a 100Hz quote, which is useless because 1/f is a bit high on this part). The Spice model is pretty accurate too, and it has a low source-resistance. From source-resistance and transductance you can ballpark the noise. But all this is a bit off topic don’t...

1.5nV. Got one on my bench now. Read TAOE

You mean, creating a sparse sampled array? Sorry, dont know much about that.

Ad743, AD745 are fast enough for 1kHz sounds, LT1113, LT1792 and the newer ADA4817 are low noise candidates from Analog Devices. The sub 1nV preamp in TAOE is in figure 3.3.4 page 152.

OMG, did you see that price? You can get those in SMD for 38cts/piece, or 10cts/piece per 1000. But try the opamp first, opa1642 or 1654, opa134 etc...

PS I don’t understand the unit on that Y axis. Shouldn’t that be dB re 1uPa/sqHz. ?

Some comments: For low noise you can try J309,LSK170,LSK489,INF3601. J309 is 35 cents and will be much lower capacitive load too. Look in The Art Of Electronics 3rd edition for a 1nV/sqHz preamp example and more info on low noise jfets. I use OPA1654 as my default go to piano. It has...

that is a nice website with examples... You could start with something simple as this:

Well, I would keep the signal analog and design an analog switch bank. Or were you thinking ADC to teensy routed to serveral DACs?

You can use 12 switching JFETs like J175. Use 12 GPIO to turn on and off those JFETS.

Single GPIO and a resonator tank after it. Modulate the amplitude with a LDR? Or JFET?