DSP Radio version 3.0 is ready for sale at tindie

A project log for Radio, yes AM-SW-FM radio by DSP radio chip

Just a decade ago, shortwave radio should be made of bunch of coil and resonators. Nowadays, nothing needed!

kodera2tkodera2t 09/07/2016 at 13:3714 Comments

The initial one surely receives from lower frequency to FM broadcast, but some points are pointed-out by great customer.

(1) Necessity for 3.3 V regulator circuit.

Rating voltage of KT0915 is 3.3 V but full-charged Lipo approaches 4.0 V. In my experience, KT0915 can work around that voltage but I surely need to use low voltage drop regulator. Actually I ignored existence of excellent low voltage drop (around 0.1 V) regulator and using it radio (KT0915) can work even less than 3.7 V. (Rating voltage of KT0915 is 3.3 V). So I added regulator circuit

(2) Digital volume control utilising KT0915 function

Actually KT0915 has "digital volume control", which function can be activated by certain internal register through I2C. Indeed it is surely much more straightforward way than putting ohmic variable resistor for volume control, so I put the function init.

And this is version 3, including improvement along the comment from great customer!!

Basically the circuit is same but as we see, some parts are added. Along this modification, I've uploaded new firmware for volume activation for github! As same as previous version, "semi-kit" will be available at my tindie store (after admin of tindie admission).

In addition, I've received some comment for difficulty of small SMT chip soldering especially LED so..

I've populated two tact switches, LED, in addition to firmware-written Mega328, KT0915, TP4057 (Lipo charger) and 3.3 V regulator. The semi-kit will be available in the following form.... Stay tune on my tindie store! (not DSP radio version 2 but VERSION 3!)

Actual operation can be found in the following movie... Have fun!


loparic.slavko wrote 12/27/2018 at 18:56 point

wrote 12/08/2018 at 21:45

I have bought at a complete DSP Radio Version 3.

However, for each frequency change I have to increase volume which I found very inconvenient.

Therefore, I would like to kindly ask you for a firmware without "Digital Volume Control Function" but with preserved high quality AM signal reception.

Finally, I would be grateful for instructions about how to upgrade the firmware in the receiver. Thank you in advance!

Looking forward to your feedback

Best regards

Slavko Loparic

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Joel wrote 02/22/2020 at 22:28 point

Hi, I have noticed this same thing, it would be nice if the author would fix this.

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Jabí wrote 01/08/2018 at 06:23 point

Not is possible demodulate LSB and USB modes?

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kodera2t wrote 01/08/2018 at 06:39 point

Internal signal (IQ-demod) is not obtained to external, so reception is AM or FM only... unfortunately..

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Joel wrote 06/05/2017 at 14:51 point

What is the LiPo chip controller on board of the DSP radio? I can't read it on the the schematic, too low resolution. It has 3B3 on it?

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kodera2t wrote 06/07/2017 at 19:42 point

Hello, it is TP4057. 3B3 is a 3.3V Toshiba's regulator.

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Steve Smith wrote 05/24/2017 at 10:53 point

Could you let me know the frequency range in full and is there any chance of CW/SSB reception? - Cheers.

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kodera2t wrote 05/24/2017 at 13:25 point

Hello and thank you for interest. The radio surely covers several amateur (and professional) band but unfortunately reception is limited to general AM demodulation or FM wide mode demodulation. Before I searched several internal register of the DSP radio chip whether some "hidden" setting permits SSB demodulation or not but it seems not... Thank you and sorry for that..

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Joel wrote 05/15/2017 at 17:07 point

I modified FM startup frequency and uploaded to DSP Radio. Radio is working on right frequency, but display not working anymore. I only changed startup frequency, why no display?

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kodera2t wrote 05/16/2017 at 03:13 point

Hello ! Please use driver in

The key is in Adafruit1306.h line 60 to 62

   #define SSD1306_128_64 

//   #define SSD1306_128_32

//   #define SSD1306_96_16

this part defines  128_64 or 128_32. Please try switching this part.

Thank you!

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Joel wrote 05/16/2017 at 03:32 point

I have the Adafruit 1306 Library installed and the sketch version 4 compiles fine just no display. I will check lines 60-62. Thank You

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Joel wrote 05/16/2017 at 15:22 point

That worked fine, thank You.

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Joel wrote 04/24/2017 at 23:18 point

Hi, Is that a  SPI display?

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kodera2t wrote 04/24/2017 at 23:38 point

No, it's I2C connection.

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