rtvdxro/tef6686-am_fm_rds-radio

HIgh performance AM/FM RDS software-defined radio signal processing tuner with NXP TEF668X and I2C Arduino Controller for XDR/NXP/TEF GTK user interface

HIgh performance AM/FM RDS software-defined radio signal processing tuner with NXP TEF668X and I2C Arduino Controller for XDR/NXP/TEF GTK user interface ( for old "historical" versions visit rdi.boards.net ! )

Antenna Switch option:

Ant A = Normal

Ant B = iMS enabled ( FM multipath suppression when the receiver is in a moving vehicle )

Ant C = EQ enabled ( FM channel equalizer for improved field performance )

Ant D = Both enabled

Audio output level is fixed -> 0dB or +3dB or variable in new " Beta pack "

For AM the following four bandwidth settings are supported:

3 / 4 / 6 / 8 kHz

For FM the following sixteen bandwidth settings are supported:

56 / 64 / 72 / 84 / 97 / 114 / 133 / 151 / 168 / 184 / 200 / 217 / 236 / 254 / 287 / 311 kHz

On modified NXP/TEF-GTK user interfaces the bandwidth parameter values now fits well.

In some third party XDR-GTK altered interface versions available on internet the word "Ant" has been replaced by others such also the funny "DX" which, apart from the word itself on a button, doesn't bring a real "DX", a plus of performance on weak fringe RF signals, being only just linked to some variations of tone corrections through DSP that modify the audio signal after demodulation ... just to impress the fools :) Likewise the option to adjust the gain in the GTK interface also for the "IF" , which on TEF668X is missing being only available for the "RF", not also for the "IF"! The command is the same for both value options, but the naives don't know that! :)

Great special thanks to Konrad Kosmatka, author of the original & brilliant version for Sony XDR-F1HD

https://fmdx.pl/xdr-i2c/

https://fmdx.pl/xdr-gtk/

and also to ( in alphabetical order ):

• ace919
• Brian Beezley
• dxhdtv
• eggplant886
• fmdxbp
• Jan Kolar
• Marcin Woloszczuk
• Mihai Popa https://github.com/stailus/tef6686_rds
• makserge https://github.com/makserge/tef6686_radio
• Nicu Florica http://nicuflorica.blogspot.com/2020/02/radio-cu-tef6686.html
• ODJeetje
• Olivier Guillaume
• Przemyslaw Korpas
• Sjef Verhoeven https://github.com/PE5PVB
• VoXiTPro https://github.com/voxit1512/Tef6686

and many other enthusiasts ...

Tested on Arduino Nano V3.0 at 5V

Feel free to add your own contribution to this nice project !

tef6686-am_fm_rds-radio's Issues

Volume control is not working

Hi,
I got a TEF6686 module from aliexpress, hooked it up and it is working.
The module is with TEF6686 v102 (F8602) and looks exactly the same as the photo in this github repository.
There are three versions of NXP-GTK here and I am not sure why and what's the difference between them. However, when I used TEF6686GTK102mp.ino with any version of NXP-GTK, volume slider did nothing (at least nothing audible).
When I used the .ino file from marsel90's repository, volume slider worked OK.
Another question - squelch does not work with either .ino file, is this supported at all by the TEF chip?

RF noise from arduino

Hi,
this "issue" is not an issue with your sketch... just a place to discuss.
I built the following circuit on a 2-sided board where the top side is GND.

Now the problem is that, without antenna connected, a strong local station sounds distorted and with noise (like when it has a weak signal), but when I push the Reset button on the arduino, noise disappears and audio is very crisp. It also happens when the arduino is being programmed from arduino IDE - which holds the atmega in reset as well.
I would very much like to have this reception quality always, not only when pressing the reset button. But everything I tried, failed:

• ferrite bead or 220uH choke on Arduino +5V with 220uF and 100n capacitors on both sides of the choke
• various sleep modes in arduino code
• disabling any I2C/serial communication after tuning to a station (I am trying to make this a standalone tuner, not requiring a PC for basic tuning)
  I don't know what to do next. Maybe shielding the arduino module with sheets of metal?
  I didn't connect the antenna on purpose, to test this. You can try it as well if you wish. I'm not able to find anything on arduino making RF noise (I encountered this problem also in my other circuits with bare atmega, where I wasn't able to solve it either).
  Any suggestions, please?

Steps AM

Is it possible to change the steps in 1 khz? Now it is 9 or 10 khz.
But here in the Netherlands there are stations off channel, so that would be nice if possible

Quality of signal is low, no RDS

Hello !
I just received module with TEF6686 from aliexpress and created test board using schematic and scripts from this project.
What i got: soft works ! But quality of signal is low (~30 dBf), all options are default.
I use simple wire as antenna - just as on the drawing. Maybe wire is not enough ?
here are pictures of the test board :

Here is program screenshot :

Thanks for help !

V205 User Manual

Please add this to the repository for completeness:

UM_Radio_TEF668XA_V205.pdf

Thanks.