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  • DD4WH's Avatar
    09-16-2019, 04:30 PM
    Hi Jim, sorry, there is no wiring diagram, but there is plenty of information on the Internet for low-IF SDRs like this. There is some more information in the pdf to the Teensy SDR...
    225 replies | 54267 view(s)
  • DD4WH's Avatar
    09-16-2019, 04:26 PM
    I would recommend to resolder all of your solder joints underneath the Teensy under magnifying glasses or a stereo microscope. I can see some partly unsoldered or looking "cold", eg. pins 17, 18, 21. All the...
    13 replies | 147 view(s)
  • DD4WH's Avatar
    09-16-2019, 02:27 PM
    Hi Peter, now thats strange, did you use the latest version from my github? It has the following in line 191 which should work: extern "C" { void sincosf(float err, float *s, float *c); }
    225 replies | 54267 view(s)
  • DD4WH's Avatar
    09-11-2019, 07:15 PM
    I am not sure about the requirements of a VOX application, but I think a signal level measurement should be sufficient. You will not be that far from the mic in order to make reliable communication? So I think a simple...
    8 replies | 1389 view(s)
  • DD4WH's Avatar
    09-11-2019, 07:06 PM
    No, unfortunately not. I spent many hours on that and have not succeeded in performing reliable I2S In and Out with the Teensy 4.0. The very same hardware (Teensy Audio Shield, PCM1808 & PCM5102) with the T3.6 work...
    68 replies | 3998 view(s)
  • DD4WH's Avatar
    09-02-2019, 08:52 PM
    I have been trying to use the Teensy 4.0 with the PJCR Teensy Audio shield to get I2S audio input and output. The audio shield was soldered with very short wires (< 2cm) and 100 Ohms series resistor in MCLK. photo...
    0 replies | 77 view(s)
  • DD4WH's Avatar
    09-01-2019, 07:41 PM
    As far as I understand, it is indeed necessary in order to cancel out the opposite sideband in SSB. But if I understand it correctly, in the Convolution filter, the complex filtering of both channels already does the...
    16 replies | 461 view(s)
  • DD4WH's Avatar
    09-01-2019, 03:14 PM
    Hi Derek, thats very interesting stuff! For me as a non-engineer, there are a few points that are not easily understandable: 1.) SSB: Where is the Hilbert transform in Fast convolution filtering in the frequency...
    16 replies | 461 view(s)
  • DD4WH's Avatar
    09-01-2019, 11:18 AM
    I have to apologize, I did not read your post well: you wanted PCBs, here they can be purchased: https://aisler.net/daba/are-ssr-1/are-ssr-2 You can also contact Dante via this thread: ...
    225 replies | 54267 view(s)
  • DD4WH's Avatar
    09-01-2019, 11:02 AM
    It is all here: https://github.com/do7jbh/SSR-2 Dante DO7JBH has his own software that runs on his hardware, but the Teensy Convolution SDR also runs on his hardware.
    225 replies | 54267 view(s)
  • DD4WH's Avatar
    08-30-2019, 06:44 AM
    Unfortunately, I have to say that the crackling noise returned. I made numerous attempts to cure that by returning to sample rate 44100sps, by inserting different resistor values into the MCLK line, by changing the...
    68 replies | 3998 view(s)
  • DD4WH's Avatar
    08-29-2019, 07:45 PM
    Hi Derek, I am really impressed, that seems a really nicely structured SDR layout! I will soon make an attempt to try it out! However, when compiling, "Streaming.h" is missing. Where can I find that? All the...
    16 replies | 461 view(s)
  • DD4WH's Avatar
    08-29-2019, 06:16 PM
    @bicycleguy: looks good! My working setup is very similar! How high can you tune up the sample rate until your setup gives distorted audio?
    68 replies | 3998 view(s)
  • DD4WH's Avatar
    08-29-2019, 06:14 PM
    Just one thing to add: we have exactly the same phenomenon of I2S synch error with the following hardware combinations for our Software Defined Radio Software UHSDR: STM32F4 & WM8731 STM32F7 & WM8731 STM32H7 &...
    16 replies | 231 view(s)
  • DD4WH's Avatar
    08-29-2019, 06:06 PM
    @Blackaddr: Thanks a lot! After hours of searching for my issue, I resoldered all connections and now the T4 & audio shield combination seems to work reliably up to 120ksps sample rate. With higher sample rates, there...
    68 replies | 3998 view(s)
  • DD4WH's Avatar
    08-21-2019, 08:50 PM
    hi Brian, re: 1.) have a look at https://github.com/g0orx/wdsp/blob/master/firmin.c line 243: "k = (k + a->idxmask) & a->idxmask;" I am not sure how I should interpret that (and maybe this causes the faults...
    20 replies | 795 view(s)
  • DD4WH's Avatar
    08-21-2019, 08:21 PM
    Blackaddr, thanks a lot for your detailed explanation! OK, I now understood the difference between the I2C and the I2S problems ;-). But I am still struggling with my problems, could not cure them with the code. ...
    68 replies | 3998 view(s)
  • DD4WH's Avatar
    08-21-2019, 08:11 PM
    Brian, thats excellent news! I am far from understanding the code by Warren Pratt from his wdsp lib, so playing around until the result is what we want is exactly the right way to find the optimal solution in this case...
    20 replies | 795 view(s)
  • DD4WH's Avatar
    08-20-2019, 07:30 PM
    Hi Brian, thats indeed strange. Thanks for your measurement effort, thats not possible here at my work bench :-). As you said, one block of 128 samples is fed into the audio chain, and one block is sent out. With...
    20 replies | 795 view(s)
  • DD4WH's Avatar
    08-20-2019, 07:23 PM
    @Blackaddr: could you point me in the right direction where I could add your register settings (in which file)? I tried to add them in my sketch in the setup, but no success, it seems to make no difference. //...
    68 replies | 3998 view(s)
  • DD4WH's Avatar
    08-20-2019, 07:49 AM
    Very interesting! It would be nice to know where and how exactly you changed the files (but maybe that will soon be incorporated in the next Teensyduino version?). I would just like to report my very similar...
    68 replies | 3998 view(s)
  • DD4WH's Avatar
    08-19-2019, 08:58 PM
    You are probably right, I now soldered the T4 and the audio board with very short wires and its still quite sensitive, I use a lower sample rate (and a lower MCLK freq) for the moment in order to be able to experiment....
    20 replies | 795 view(s)
  • DD4WH's Avatar
    08-19-2019, 08:46 PM
    Pete and FrankB, you saved my evening! :-) Thanks a lot for the code, works fine for the Teensy audio board and T4!
    5 replies | 412 view(s)
  • DD4WH's Avatar
    08-19-2019, 06:22 AM
    Hi Brian! yes, first I tried your convolution object with the T4 and it worked nicely! The reason why I put up this sketch was: * it is Stereo * it divides the processor load evenly between audio blocks * it...
    20 replies | 795 view(s)
  • DD4WH's Avatar
    08-17-2019, 06:44 PM
    To test T4 performance I extracted the fast convolution filtering code from my SDR and tested it with the Teensy 4.0 and the Teensy audio board. Both were connected with flying wires (MCLK with 100ohms series resistor)....
    20 replies | 795 view(s)
  • DD4WH's Avatar
    08-17-2019, 01:39 PM
    Hi! it seems it does not work properly with the library as it is at the moment. I used the SGTL5000 audio board, connected it to the T4.0 and used the guitar example. Additionally to the original example I added...
    3 replies | 181 view(s)
  • DD4WH's Avatar
    08-16-2019, 08:04 AM
    Thanks for your input! When using the DAC alone, it works perfectly both ways: either with SCL connected to GND (PLL mode) or SCL connected to pin 23 (using MCLK from the Teensy 4.0). But when I additionally...
    68 replies | 3998 view(s)
  • DD4WH's Avatar
    08-15-2019, 06:22 PM
    Oh, did not know that. I left SCL of the DAC unconnected. When testing with the Convolution object by DerekR I experienced strange crackling noises. Could it be that this is caused by this? I will try to connect...
    68 replies | 3998 view(s)
  • DD4WH's Avatar
    08-15-2019, 03:07 PM
    Thanks again for the hints! ADC works together with DAC ! Connections for documentation: Teensy 4.0 with ADC PCM1808 module (line-in Input), running simultaneously with the DAC PCM5102 (headphone output): ADC...
    68 replies | 3998 view(s)
  • DD4WH's Avatar
    08-15-2019, 02:02 PM
    Thanks for that hint! Is working now. Just for documentation for others to try: Teensy 4.0 and DAC PCM5102 module from AliExpress Vcc = Vin GND = GND FLT = GND SCL = floating BCK = BCK = pin 21 DIN = TX = pin...
    68 replies | 3998 view(s)
  • DD4WH's Avatar
    08-15-2019, 06:55 AM
    Could you post your sketch for using the PCM5102 with the Teensy 4.0? Or did you just use an example sketch? If yes, would be nice to know which one you used. Thanks a lot! Regards, Frank DD4WH
    68 replies | 3998 view(s)
  • DD4WH's Avatar
    08-15-2019, 06:53 AM
    DD4WH replied to a thread Bat detector in Audio Projects
    Hi Edwin, thanks a lot! I will think more about that! However, adding additional hardware for features already implemented (built-in SD card) is a bit annyoing, and I think I read that the built-in SD card is much...
    462 replies | 34116 view(s)
  • DD4WH's Avatar
    08-14-2019, 07:09 PM
    DD4WH replied to a thread Bat detector in Audio Projects
    well, then we will never know or solve the problem with the noise that you have . . .
    462 replies | 34116 view(s)
  • DD4WH's Avatar
    08-14-2019, 07:06 PM
    DD4WH replied to a thread Bat detector in Audio Projects
    Hi Corbee, it could well be that the 23kHz noise is associated with the wrong connection of the central pad which must be left totally unconnected in single ended mode. But we do not know if you do not have a closer...
    462 replies | 34116 view(s)
  • DD4WH's Avatar
    08-14-2019, 06:39 PM
    DD4WH replied to a thread Bat detector in Audio Projects
    Hi Corbee, as I stated, the spectrum is from 0 to 250kHz (500ksps sample rate !), you have to multiply the frequency axis by 10 ;-). Your spectrum looks good, except for the peak at 23kHz. How did you connect...
    462 replies | 34116 view(s)
  • DD4WH's Avatar
    08-14-2019, 05:49 PM
    DD4WH replied to a thread Bat detector in Audio Projects
    strange, I updated the spectrum, can you see it now? Its visible here . . .
    462 replies | 34116 view(s)
  • DD4WH's Avatar
    08-14-2019, 04:53 PM
    DD4WH replied to a thread Bat detector in Audio Projects
    Here is a spectrum of a recording with the ICS40730 made in Audacity: As you can see, the scale is from -70 to -90dB on the y-axis, so there is no pronounced noise at a certain frequency, its all below -70dBFS,...
    462 replies | 34116 view(s)
  • DD4WH's Avatar
    08-14-2019, 04:46 PM
    DD4WH replied to a thread Bat detector in Audio Projects
    Hi Edwin, sorry for being silent so long. I have some experience with the ICS40730 and can only say its the most powerful ultrasound MEMS I have ever seen . . . it can pick up ultrasound up to 160kHz and is highly...
    462 replies | 34116 view(s)
  • DD4WH's Avatar
    08-12-2019, 08:40 AM
    Hi Valeri, well thats explainable: * there are different options to use the oscillator chip Si5351: which clock output do you use? and which Xtal frequency did you install? These six different options alone...
    225 replies | 54267 view(s)
  • DD4WH's Avatar
    08-12-2019, 08:36 AM
    Hi FrankB, thanks a lot for your simulations of the input filter! I am a little puzzled about that difference in comparison to my simulations with ELSIE . . . Will have to think about that and try to simulate a...
    225 replies | 54267 view(s)
  • DD4WH's Avatar
    08-12-2019, 08:32 AM
    It will probably take us a while to account for the changes in Teensy 4.0. At the moment I am not sure whether it will compile and/or work with the T4. I do not own a T4 yet, but the order is already on its way to my...
    225 replies | 54267 view(s)
  • DD4WH's Avatar
    08-12-2019, 08:27 AM
    There have been several people with that plan. But as far as I know, nobody has published code for that. If you are interested in an SDR transceiver code, you might have a look at UHSDR (however, developed for the...
    225 replies | 54267 view(s)
  • DD4WH's Avatar
    08-12-2019, 08:23 AM
    you seem to confuse the "Teensy SDR" with the "Teensy Convolution SDR". The former is using all 16-bit integer math and uses blocks as in the audio library. So your proposed way of using it should perfectly work! ...
    225 replies | 54267 view(s)
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About DD4WH

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About DD4WH
Location:
Central Europe
Interests:
Software Defined Radio, Digital Signal Processing, Bat detection & bioacoustics

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Teensy Convolution SDR (Software Defined Radio) 09-16-2019 04:30 PM
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10-25-2015