Multiband Receiver

Multi-band radio based on NXP TEF6686

Demo video:

Introduction to multi-band radio based on TEF6686-Bilibili

QQ communication group: 616786582

If you have any questions, you can join the group and ask~

Receiving Range

System introduction

• • RF reception: NXP TEF6686 DSP single-chip reception, supports antenna feed, with S meter indication, supports RDS.
  • Power supply: TYPE-C fast charging input, built-in charging power management, 8000mAH lithium battery.
  • Audio: Maxim DirectPath 50mW headphone amplifier, dual Class AB 3W amplifiers, audio VU indicator.

More

• • Backlight brightness is adjustable and can be turned off, backlight time is adjustable, and contrast is adjustable.
  • The threshold and speed can be set for automatic station search, and stations can be saved manually. Number of stations saved: 100*FM, 100*SW, 50*MW, 20*LW.
  • Power-off memory settings and saved stations.

Button function

The FM band effect is excellent, and the AM reception effect is also good. You can increase the reception effect through an external LNA.

The accessories for the 3D printed shell have been uploaded. The screws are self-tapping with M2*(6,10) and M3*8.

4 buttons need to be printed in the 3D print.

2022.4.14

The production guide has been uploaded as an attachment~

2022.4.29

Everyone's enthusiasm is a bit high, so I plan to update a cost-reduced version in the future. If you want to make it, you can wait.

The main control is planned to be replaced by the domestic GD32F103RCT6, but since I am not very familiar with GD32, plus I am a bit busy with studies and don’t have much living expenses, the development time should be relatively long.

Of course, this version can also be used now (the STM32 version has been dismantled and cannot be maintained anymore. Please make a GD32 version).

2022.5.25

The GD32 version has been successfully verified and the UI has been optimized. However, during the process of making the GD32 version, I dismantled the STM32 version machine, so the STM32 version can no longer be maintained. In the future, only the GD32 version will be maintained and updated.

The production process is similar to the STM32 version, but the firmware download is changed to USB-to-serial port download. No downloader is needed, only a USB data cable and the official download software are needed.

Keil project files, BOM, 3D printing files, download instructions have included project attachments, PCB is still open by clicking the editor in the upper right corner, Board3 and Board4 are the GD32 version , please don’t enter the wrong board.

V2.0    (2022.5.25)
--GD32 version 6686 radio first version program.
--Use the GD32F10x_Firmware_Library_V2.2.2 standard library to transplant the STM32F4 HAL library program.
--Adjusted the UI style of the main interface.
--Remove BIAS settings from EEPROM.

V2.1    (2022.5.30)
--Fixed the bug that the AM station could not be saved after power off.
--Fixed the bug of quick station search in shortwave band.
--Added a very cute startup animation (bushi.

V2.2    (2022.7.6)
--Added this README.TXT documentation.
--Voltage display changed from rounding down to rounding.
--Eliminate some possible timing conflicts.
--Added screen brightness DC offset adjustment.
--Optimized the speed of S table.

V2.3    (2022.7.21)
--Increased system response speed.
--Should have eliminated most of the timing conflicts.
--Adjust IIC waveform to increase communication rate.
--Slightly optimized the accuracy of FM station search.
--Fixed the bug where the data stopped updating after the homepage search reached the end.
--Added animations for searching channels on the home page and searching channels in the full frequency band. Now it doesn’t look like it crashes when searching for channels.

V2.4    (2022.7.27)
--Modify the DAC dimming formula.
--Modify boot animation.
--Reset menu.
----LCD related setting items (bias voltage, scan rate, reverse display)
----Audio gain adjustment.
----FM enhancement is divided into channel equalizer and multipath interference suppression.
----Support MPX output.
----The channel search threshold is adjustable.
----The upper and lower limits of FM search station are adjustable.
----Medium wave stepper 9K/10K.
----Added attribute viewing (DSP identification, system version, MCU unique ID, MCU information, temperature (offset reference), internal reference)
----Added IRC40K calibration function.

V2.5    (2022.8.6)
--Added support for V205 (F8?05)
--Added support for FMSI (TEF6687/6689 only)
--Greatly improve the accuracy of station search.
--Fix the bug that the backlight will not turn off after booting.

V2.6    (2022.8.26)
--Automatically identify the radio chip version number.
--Automatically adjust to the last station that was played continuously for more than 10 minutes when the computer is turned on.
--Adapt to the new screen driver board (adjust nBLBaseline to 0)

V2.6.1    (2022.8.27)
--Greatly speed up booting.

V2.7    (2022.9.4)
--Added the function of deleting radio stations.
--Modify the noise output algorithm.

V2.8    (2022.9.11)
--Reduce the mute time of FM switching channel.
--Modify the search algorithm
ATS Mode slow speed is the algorithm used in previous versions and has a higher recognition rate.
ATS Mode is a new algorithm that greatly improves the speed of channel search while ensuring the basic recognition rate.
--Increase maximum volume from 31 to 39
--Entering the Memory menu will automatically tune to the first channel.

V2.9    (2022.9.23)
--Add an FM station search algorithm.
ATS Mode -> AF enables the new channel search algorithm, which allows you to search for channels while listening.
* The station search speed, accuracy and recognition rate of this mode are relatively low.
--Adjustable sine wave generator.
--Fine-tuning the effects of different levels of FMSI.
--Fixed the bug that FM cannot be restored after forcing mono.

V2.10    (2022.10.5)
--New Advance menu, adjustable radio processing system as follows:
---Noise Blanker（AM/FM）
---Softmute（AM/FM）
---Highcut（AM/FM）
---Dynamic Stereo（FM）
---Dynamic Stereo Hiblend（FM）
* STL0-2 will turn off the last two stereo processing systems and enable the more advanced FMSI stereo processing algorithm.
--Added support for RDS.
---Currently supported RDS information: PI, PS, PTY, RT, CT * Only PI, PS, PTY are currently displayed.
--Modify the maximum volume to 32. The first 31 levels of volume are not modified. Volume 32 will bring a 6dB gain.

V2.11    (2022.10.17)
--Fixed the bug that the Memory interface cannot adjust the channel in AM mode.
--Fix ADC clock configuration error.
--Restore system response speed.
--Added storage of Advance menu.
--Remove RDS PTY display.

V2.12    (2022.11.26)
--Improve LCD communication speed.
--Optimize encoder experience.
--Slightly speed up booting.
--Reduce interruptions.
--Add illegal character judgment.
--Add scheduled sleep function.

* Due to hardware limitations, there is a certain amount of sleep power consumption