Thread: HU Quality AM/FM RDS/RBDS Radio with Features

I received the tuner modules today. These are the vertical mount parts since they were available for quicker delivery. They are electrically equivalent to the horizontal parts and we'll probably just modify the shield and bend the pins for our quick and ugly prototype. If everything works out, we can easily switch to the horizontal mount units for a production kit batch or fully assembled boards.

I've confirmed that these modules use the Philips TEA6848 tuner. There should be no problem getting these to play nice with our Philips TEF signal processor. The two are optimally tuned to work with each other. Microtune's own evaluation kit even uses uses the TEF!

Things are looking good. Check the Design C status section of the FAQ for the latest pictures and schematics.

rando,

My project does not meet some of the project goals. I'm going for a home or portable use receiver. Mine will be controlled with buttons and an OLED display. I've talked to a sales rep today from Microtune and plan on buying the design kit or the evaluation kit (or both if I could afford 1k, just to play around). I chose the TDA7433 from ST Micro because it has two stereo inputs, which is what I want. One for the C-QUAM decoder and one for the MPX decoder. One of the main points in using the Philips DSP is the high quality MPX decoder with multipath detection and high perforemance in weak signal conditions. But no AM stereo. :P While most stations don't broadcast AM stereo and most people don't listen to AM, I still listen to my oldies station which broadcasts in AM stereo. Also, in your design you chose to have the PIC to the processing of the RDS data. Since My programming skills are nil, I'm going to use the SAA6588 which places processed RDS data right on the i2c bus. I'm doing a much simpler design, but I'll do my best to get good performance with the tuning. I just have to find a good MPX decoder and I'm set. I also need a place to find an MC13020 or MC13022 C-QUAM decoders too. I'm also thinking of putting op amp buffers on the audio outputs, but the TDA7433 seems to be able to handle most input impedances well.

With so many projects going on, money is really the only issue. I have already $130 in digikey parts and more are going to be added once I get all the hard to find parts like the tuner, eval or design kit board, and the OLED. Philips is pathetic with the lack of info in their datasheets, so before long I might just go with an MPX decoder from ST.

Sounds cool. Perhaps we can coordinate our firmware (PC side) interfaces such that a single driver, or at least a single API can be used to control any of the designs.

It's true, Design C will, for now, do the RDS decoding in the PIC. However the TEF6982 is a drop in replacement for the 6980 and it includes the RDS decoding functionality. We had a problem sourcing the 82. From the PC side though, this will be transparent since the firmware must deliver a decoded stream either way. To ease our development burden, we might do the decoding on the PC to begin with. Even in that case, it will be transparent at the API level. Once it's working we can port it over to the PIC.

Design A uses a seperate RDS decoder similar to yours.

Design B may be using the 6982. We'll have to wait for racemier to tell us more to be sure.

How will you go about implementing your firmware to control the radio without any software skills? Maybe I missed something about your intended design.

As for the button control and integrated display, that's something we've considered too. I believe our design should have enough free I/O and cycles to easily accomodate such a solution. The ability to extend the design to do extra things is definitely one of our design goals -- even if it's not explicitly stated in the FAQ.

Correct ,design B uses TEF6982. I received some samples from Philips a week ago.

Originally Posted by racemier

Correct ,design B uses TEF6982. I received some samples from Philips a week ago.

Cool great choice! Any chance you can spare a sample or two?

Originally Posted by rando

Cool great choice! Any chance you can spare a sample or two?

I only received 2 myself, they were not very generous with the number of them still it makes me happy they sent two

Since I'm waiting on parts to arrive I decided to to take a first stab at a simple firmware to support initial testing. It's not tested yet beyond the MPLAB simulator but appears to work fine there. It just implements a very simple PC->I2C bridge via a PC serial port using the target PIC18F2455. It should run on just about any 18F chip with USART and I2C peripherals.

This will need quite a bit of enhancement for production use but it's a starting point if anyone wants to iron out a PC side interface and subsequent API implementation. For the API itself, I'm thinking of something that is Radiator compatible PLUS extensions to support AM, RDS and the other functions provided by the hardware (fader, balance, volume, bass, treble, inputs, ...).

I received the TEF signal processors today. I plan to have something ugly hacked up soon. A pretty implementation will take a bit longer. Stay tuned!

Originally Posted by rando

Stay tuned!

I've been watching this thread for 5 straight days. Can I take a break? I need to eat something...