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

racemier,

I thought it was French, but wasn't sure. She is definately beautiful though. Anyway, I'm quite pleased with your progress. When you finally get the software done and ready to sell these I'm definately buying one. My project (if I actually get it from paper to a proto board) will be using a different audio processor (TDA7433) and the same RDS/RBDS IC (so I won't have to bother with RDS functions in the firmware). The audio processor is a basic one, not one designed for car audio. So I'm using the TDA7040 MPX decoder for FM and an MC13020 C-QUAM decoder for AM. Both ICs will accept a mono audio signal, so all I'll need is two stereo inputs on the processor. The audio outputs will be buffered, and an amplifier will be required. Also a headphone amp will be included. My project will be more of a portable or home receiver than for a car, but that's where your's comes in.

Also, the 74LS05 i2c interface is really simple. I found a schematic here. What software are you using?

Seth,

Philips told me the TEA6849 is obselete! No samples available. But since Microtune did the hard work, I won't need one. But thanks anmyway though. Now I just need a supplier for the MC13020.

Originally Posted by emumanXM

Seth,

Philips told me the TEA6849 is obselete! No samples available. But since Microtune did the hard work, I won't need one. But thanks anmyway though. Now I just need a supplier for the MC13020.

Really?....hmmm...well screw Philips...

Microtune has updated the module structure with a new revision and I no longer know what they use instead but it doesn't really matter because :

1) Reception quality as you noticed is top notch
2) If you still want to go with Philips's audio processors (like the TEF689x series) you can because the tuner module supplies the 75.4KHz Fref signal required.

Cheers

Seth,

I've pretty much had it with Philips. I'm going to use the level output with a D/A converter on the PIC16F747 for a level meter function. These audio processors, in my opinion, really don't help in weak signal conditions, they just cover it up from what the datasheets say. And the tuner module is of performance that it's really not important. Seems like the only thing I'm giving up by not choosing a Philips car audio processor is the weak signal processing. I only need two stereo inputs anyway, one for the MPX decoder output and one for the C-QUAM demodulator output. It seems to be that I'll acheive professional and "audiophool" quality from these simple components anyway. As for the RDS demodulator, I'll have to use a crystal. Granted, 4.332MHz is very hard to find, but there isn't much else I could do. Granted, this project will have a super simple hardware design, but all I'm looking for is good perfomance, digital tuning, all bands, and professional audio quality. I'm sure I can acheive it with a TDA7040 MPX decoder and a MC13020 C-QUAM demodulator, don't you think?

FAQ updated...

I updated the FAQ to properly reflect the status of the 3 different solutions being considered. It's grown so large it had to be split into two posts. EmumanXM, if you want a section in the FAQ (design D), let me know.

Seth and I are initiating design C to maximize the chance that all of our project goals are met. This is not meant to reflect negatively in any way on the existing design(s) that you've already seen and heard. In fact we stand behind and will continue to support those solutions fully.

Design C will be based on the Philips TEF6890 signal processor modules that Seth obtained last year. Initially we believed these tuners to be incompatible with the 1384 tuner module. The latest data sheet for the 1384 tuner has changed our minds on that and we now believe the two to be a perfect match.

We will implement a prototype using a standard prototyping through hole board. To facilitate this, a small adapter will be created to convert the TEF QFP44 package to a through hole device. Only the minimum components required to demonstrate the proper functioning of the solution will be implemented in the prototype. This should substantially ease assembly and facilitate rapid development of a kit.

I hope to have some tuner modules in hand by this coming Tuesday and the TEFs by later in the week. The adapter will take about 3 weeks to have fabricated by Sparkfun. I already have several suitable microcontrollers and the passives and linear regulators are all easily obtained.

We want to get workable radios in the hands of developers and the rest of the community as soon as possible. In parallel, Seth is working to provide a familiar distirbutor for assembled radios.

You'll hear and see more about this effort as it starts to take shape.

Here's a layout teaser of the TEF adapter to give you an idea of what I mean.

rando,

Excellent work. I like your board layout. Seems like everyone is contributing their own project, I like that. I'm waiting for Microtune to contact me. Will Microtune sell me one or two modulaes for sampling and evaluation? As for the rest, I'm sticking with the TDA7433, but still not sure what MPX decoder do use. I want to use one from Philips, the TDA1592, but no useful documentation is provided. This is very frustrating. I want to use an MPX decoder with a level indicator output to use with the SAA6588 RDS decoder, but the datasheet isn't really clear on much. The TA7343 from Toshiba seems like a good choice, but no level indicator. The TDA7040 from Philips made for low component FM receivers has no level indicator either, and also no documentation is provided. And I have no idea where to even get an AM stereo IC other than to pull one out of an old car radio. I'm still waiting on the OLED too, but the tuner and the OLED are what I want to have in my hands as soon as I can. Once I get a working prototype, please put it in the FAQ.

Also, what was that i2c software racemier was using?

Thanks.

Originally Posted by emumanXM

I like your board layout.

Thanks

Seems like everyone is contributing their own project, I like that.

No, that's not the intent. We prefer that everyone work together as one team to assure that we meet all of the project goals. Still, each contributor is entitled to control the information about his/her contributions in his/her own way. At times that may mean that the entire project team is not fully briefed on the status of each individual project.

The contact listed in the FAQ indicates who 'primarily' controls the information about each particular design. Still, there's no need to PM anyone. If the info you want isn't in the FAQ, it either isn't known yet or hasn't yet been made public.

I'm waiting for Microtune to contact me. Will Microtune sell me one or two modulaes for sampling and evaluation?

I believe they do; though potentially at a significantly higher price. I also believe they prefer to avoid numerous small orders. If lots of people start contacting them for sample quantities, I wouldn't be surprised if they close that down. That's just my opinion.

Once I get a working prototype, please put it in the FAQ.

Your project sounds interesting. I'm happy to include you in the FAQ as long as you're planning an open effort and have goals consistent with this project. If not, another thread might be more appropriate. Read our goals over again and let me know.

Also, what was that i2c software racemier was using?

I have no idea. A while back he mentioned his father was working on some I2C software for him. I assumed that is what it was.