Simple SDR with Arduino Audio Tools

[@AndreasSpiess]

Excellent video! I could not have done it better! Thank you!

[@na5y]

Thank you Andreas. Kind words indeed!

[@jeroldponko7168]

Hi Ian, Another fine video. I bought several of the ESP32-A1S modules and had some breakouts made for 2.54 mm pin headers. I'll give your code a try with my QSD based on the SDR-1000 schematic. Your receiver sounded good with the 22kHz sampling rate. With the limited voice range, I'm sure even 16kHz would be adequate. Someone concluded the noise from the ESP32 was due to not connecting all the ground pins to ground. I think this noise problem was mentioned in a video on a ESP32 Walkie-Talkie project.

[@na5y]

Thank you Jerry. If you have a close look I even have a wire soldered to the grounding pad in the middle of the ESP module. I would definitely like to get the number of taps increased - I will probably trying playing around to see if I can use the ESP-DSP library for the FIR instead of the one in the arduino audio tools. Thanks again for the comment!

[@johnwest7993]

Thank you. A clear and complete explanation and implementation. You do good work. Noise problems are almost always a headache to solve, but they seem to be where I learn the most.

[@na5y]

Thank you John. I have to get this done on a proper PCB. Breadboarding is convenient but generates all sorts of problems for RF

[@SixWildKids]

I love how quiet these sort of radios are.

[@na5y]

There's some audio bandpass in the Hilbert filter that might be responsible. Compared to an analog SSB receiver there's also a lot less components involved. Thank you for your comment!

[@TheEmbeddedHobbyist]

looks like a little board i could add to my wish list. Must get my finger out and build one of your radio's. great video

[@na5y]

Thank you TEH - they are a fun little module!

[@TheGmr140]

nice project and great work!!

[@na5y]

Thank you!

[@KennethScharf]

IIRC you don't have to issue the PLL reset UNLESS you have changed the multiplier frequency. So for small frequency changes, that should not be necessary.

[@na5y]

Thats correct Kenneth - I have that specific test in my Radio code which you'll be seeing shortly. Issuing the PLL reset causes a nasty click in the output

[@na5y]

Sorry - got this mixed up with a different video. Check out this code in Radio.ino if ( mult != lastMult ) { si5351->set_phase(SI5351_CLK0, 0); si5351->set_phase(SI5351_CLK2, mult); si5351->pll_reset(SI5351_PLLA); si5351->update_status(); lastMult = mult; }

[@nil7208]

Looks like the output buffers are weak, even at 12MHz. What is your load capacitance like? EDIT : Oh wait, I forgot about the scope bandwidth.

[@phillipneal8194]

Excellent ! Thank you very much.

[@na5y]

Thank you Phillip!

[@pjmccracken]

Good old Lou calling CQ... CQ DX... from Barcelona Spain.... What is your name... YOUR NAME.... lol... He sounded a bit rough a while back but appears to have gotten a second wind. Great video, really enjoyed this as have been playing around with something similar on the teensy recently.

[@na5y]

Thank you Peter for the kind comment.

[@TheArtofEngineering]

The accent and callsign were not coherent? Went to QRZ ....all is clear now mate! Great content, I have been wanting to build some small SOTA type rigs....this is exciting stuff. Thanks for sharing - 73 de VK2AOE.

[@arduinoguru7233]

Very well don man, thanks for sharing it.

[@na5y]

Thank you!

[@theoryandapplication7197]

thank you very much

[@robyounce4636]

In your code 'run thru' you keep referring to "TAPS". What are "TAPS"???

[@na5y]

Thank you for the question Rob. In digital signal processing a "tap" is a single co-efficient in a digital filter. The process of combining a digitized signal with a digital filter is called convolution. The more taps or coefficients the better the filter - but at the expense of more computations. Balancing number of taps with available compute power is often a challenge in DSP. The article below has more infomratiion: www.quantum-machines.co/blog/introduction-to-digital-filters-01-first-things-first/

[@DXPedro]

Portuguese Hams 🫶🏼