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RDS coder board USB RS232 using ATmega32
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Summary

 

Board diagram and overview

Usage : RS232 USB

Limits, knowns problems and versions

Download

 

 

 

 

Board diagram and overview

This board is a RDS coder using an ATMEL AVR ATmega32.
This board can be controled by a RS232 link, USB interface or SPI.
TA data is displayed wiyth a LED and can be controled by :
- Hardware input
- RS232
- USB
- SPI (not yet implemented)

An activity LED toggle state on each RDS group generated.

For a stereo mode using, this board require an external 57KHz clock in phase with the tone pilot 19KHz.

Click on reactive zone from following picture for more information(connectors, Led, adjust,...)

 

 

 

 

 

 

 

 

 

 

 

 

 

Diagram and board are available in a zip file format KiCAD in Download section:


Diagram
Board
cliquer pour agrandir

ATmega32 microcontroler configuration with PonyProg :

 

Board Usage

RDS parameters ares stored in EEPROM for board initialise at power on.

This parameters can be dynamicaly modified in RAM by using interfaces (RS232,USB).

RS232 Interface :

19200 Bds, 8bits données, 2 bits stop, sans parité

SPB490 standard "RDS Universal Encoder Communication Protocol"is not supported by present software version.

At power on, a menu include command available list is displayed, as well as parameters stored in EEPROM :

USB Interface:

During first connect to PC, select board driver : file :
USB_RDS_Coder_PC_soft_and_driver/DriverWindows RDS coder/RDS_coder.inf from zip file: USB_RDS_Coder_PC_soft_and_driver.zip

The RdsUsb.exe program allow to modify all RDS parameters in EEPROM or RAM.

Complete description of these parameters is available in file : RdsUsbUserManual.pdf

Result with a PC tuner FM RDS displaying radiotext message :

 

 

Limits, knowns problems and versions

Hardware:

.

A ~2.2 MOhms resistor is necessary with TDA7330 crystal.

This resistor is missing in shematic, so you must adding it in bottom side as show in the picture

 

The 1.2 software version manage biphase coder with software process. It is necessary to replace U1(4013) and U3(74HC86) by a strap between pin 2 and 6 of U3 (74HC86) as show in the picture

 

Software:

SPI interface is not yet implemented in present version.

Only 0A and 2A groups are implemented in present version.

1.0 version use a material biphase coder and require U1(4013) and U3(74HC86).
The RDS_SOFT_BIPHASE constant should not be define in "RDS.h" file
RS232 and USB are implemented in this version

1.1 version is an intermediate version, replace by 1.2 version

1.2 version use a software biphase coder and require a strap between pin 2 and 6 of U3 (74HC86) in subtitution of U1(4013) and U3(74HC86).
RDS_SOFT_BIPHASE constant should be define to 1 in "RDS.h" file
RS232 and USB interface are implemented in this version

This board can be used for a RDS decoder, but at this time there is no available software, (perhaps in few month, time necessary for me to write code ...)

Development tools :

ATmega32 software was developped with WinAVR and PSPad editor.

RdsUsb windows software was developped with DevCpp, windows was edited with : RadASM

 

 

DOWNLOAD

Software:

USB RDS coder ATmega32 :

sources and binaries files
Version 1.0 AND 1.2

USB_RDS_Coder_ATmega32.zip

USB RDS coder PC windows

sources and binary file
driver windows
compatible with 1.0 and 1.2 version

USB_RDS_Coder_PC_soft_and_driver.zip
Hardware:
KiCAD files for RDS_ATmega32 board :

RDS_ATmega32_Kicad.zip

Complete folder (diagram + PCB ) RDS_ATmega32 in PDF format : RDS_ATmega32_Diagram_pcb.pdf

 

 

 

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