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Is this feasible? What would be the downside?

Has anyone implemented an SDR using the Teensy internal ADC's and internal DAC (or PWM)?

Hi Derek! Anything new to report on the transceiver project? Did you make any progress on the waterfall display? Joe W3JDR

Is there an Eagle or other CAD schematic and PCB file for this? Joe

I have my Teensy 3.2 programmed with a simple sine generator (Audio Library) connected to the Usb output. On my Windows 10 computer, I have a program called "Soundcard Scope". I have all the Input setup options set to "Digital Audio Interface Teensy" and all the Output setup options set to my PC...

Rev D Audio Board PCB Library I want to embed a RevD (Teensy 4) audio board in my pcb project. Does anyone have an Eagle library file for this board? Joe

Yes, anyone who knows the library exists will have seen these partial functionality test sketches. I was looking to see if anyone has built a complete radio system, along with their account of how the process went and how well the final result turned out. I have some questions that only someone...

I'm trying to create a simple test jig using the Audio Design Tool to generate a sine and recover it using the Teensy onboard ADC. My connection code looks like this: AudioSynthWaveformSine sine1; AudioInputAnalogStereo adc1; AudioConnection patchCord1(sine1, 0, adc1, 0)...

Frank I've been digging into Hilbert filters for IQ receivers using the Oak Hills software. One of the things I notice is that the typically used designs that have about 100 taps start to fall apart below about 800 Hz with resulting loss of sideband suppression close to carrier. Do you have any...

I read this as a suggestion to have a gain reduction mechanism before the ADC to avoid overload on strong signals. I agree. Joe

Thanks Rob, Actually, I'm looking for an example sketch using DerekR's SDR Radio Library. Anyone? Joe

Rob or anyone who cares to reply: Does anyone have a sketch that implements a. complete ssb/cw receiver using rhis library? I'd like to load it up and use it as a starting point for my own development. Regards Joe

I want to use the Teensy 4.0 board for some communications-quality audio filters (LPF, HPF, BPF, etc). It seems to me that the on-board ADC and DAC should be sufficient for this. Can someone point me to a project where someone has done this? Joe

Frank I think I localized the cause of the system crashing some 15 seconds or more after startup when there are no peripherals attached. It seems to be associated with no audio into the ADC, possibly causing a divide-by 0 in the twinpeaks correction code? If I initialize the "twinpeaks_tested"...

Frank I said my configuration is "well defined", not that it is what you anticipated. I was probing to see if you have any suspicion about what you would expect to happen in that configuration. I don't like the "shotgun" approach to trouble-shooting, ie; hook everything up and "let 'er rip". I...

Frank I think you don't understand. I have the Teensy, the PJRC audio board and ILI9341 display running together and executing your latest code. The GUI comes up just fine at a default frequency of 135.600, every time. This is with no other peripherals (encoders, Si5351, etc) connected. I...

Frank I have the code compiled, uploaded to the Teensy 4 and running with the audio board and display. One thing I notice is that the GUI runs for about 10 seconds at 135.600 MHz, then goes all white. Should I assume this means it crashed because I don't have the Si5351 I2c connected? Joe

Frank Just an FYI. I just now got the program to compile and load. It was complaining about a missing library "SPIN.h". I found those files on the 'net and created the library folder...Voila! The console shows a bunch of warnings and informational stuff, but the program seems to be working. If...

Frank I understand your position. I'll just have to work a bit harder rather than take the lazy way out. I'll get there.

Frank Perhaps there is confusion due to my nomenclature. In the old days, we spoke of the compiled code that executes on the microcontoller as "object" code, also sometimes as "hex" files or "bin" files. Today of course, the word "object" has taken on a whole additional meaning related to...

Frank I'm looking for an object file of a recent version of Teensy 4 Convolution Receiver that I can upload to my board and build on it with hardware peripherals one by one until I have a stable working hardware platform. Then I'll try to build the latest version of Teensy 4 Convolution...

Frank I got my Teensy4.0 board and new version audio board yesterday. Before I begin to do battle with the Arduino IDE and try to build the code, I'd like to try an express checkout of the Teensy/Audio/4.0 code. Is there a Teensy 4 Convolution Receiver object code file somewhere that I can load...

Frank I realized after I got home last night and re-read my posting that I was wrong....it's actually a 3.6 board. It throws the same error anyway. Yesterday I ordered a 4.0 board and its companion audio board. Hopefully I'll get the code to build for that. Joe

Months ago, I successfully loaded and built the then-current version of the convolution receiver under the Arduino IDE on my Teensy 3.2 board. Recently, I had a computer problem and had to delete and restore the Arduino IDE program. I did that and reloaded TeensyDuino. Now, when I try to compile...

That's it...thanks!

Thanks Frank What I find there are jpegs and pdfs, not CAD files. Of course, a ready-made board I can purchase would give a jump start.. Please advise if I'm missing something.

I'm trying to reproduce the hardware design for this receiver by DO7JBH, Dante. Can someone tell me how to contact him, or if boards/board files are available somewhere on the net? Joe W3JDR

Transceiver Frank Have you, or has anyone you know of, made a transceiver version of this project? Joe W3JDR

I have these boards plugged together in a stack. Without the audio board in the stack, I can get the color display to work with the example sketches using pins 9 and 10 as DC and CS. When I put the audio board in the stack, even modifying the defines to pins 20 and 21 per the web page, all I get...

Thanks I wanted to look at the schematic of the interface board to see how the I/O is mapped from the Teensy to the display, but there apparently is no such document. Guess I'll have to buzz it out with an ohmeter. Joe

ILI9341 - No Display I'm running the code below on a Teensy 3.2, and a PJRC ILI9341 color display board with the recommended Osh Park "purple board". All I get is a white (blank) screen. The main loop seems to be running, as indicated by the print. Any suggestions? #include <ILI9341_t3.h>...

Thanks for the insights.

Aha! In looking through one of the Hilbert coefficients listings, I see why they're not scaled against a larger value. Some of the coefficients in the file I'm looking at go up to 0.87, so scaling against any larger value than 32768 would possibly overrun a signed 16-bit integer. Any idea why...

In looking at the coefficients, it appears that, not only will some values cast to zero, many of the others will be severely limited in resolution. Do you know if there was a reason why the code not written to scale the coefficients with a larger number than 32768 and then cast into Longs?

I'm curious how/why this works. It seems that the result of the multiply is a larger number than can be cast into a Short, unless: 1) A Short in this compiler is 4 bytes 2) Some precision is lost when the result is cast into a Short Educate me please Postscript: I failed to see the E-18...

That seems to have fixed it...thanks!!! Joe

I've also been having difficulty compiling the code at https://github.com/rheslip/Teensy_SDR. I'm running Arduino 1.8 with the latest Teensyduino installed w/no problems. When I attempt to compile, I get about 100 warnings and errors which I'd gladly post here if everyone is OK with such a long...