TheRadioBoard

Some sources seem to indicate it is 192 kHz:
http://www.arrl.org/news/surfin-what-a- ... til-monday
http://processors.wiki.ti.com/index.php ... edirect=no

The TI page has conflicting information, stating both 48kbps and 192kbps on the same page for for codec in question (tlv320aic3204):
http://www.ti.com/product/tlv320aic3204 ... 553x-pr-pf

Could be, I am not familiar with this family of codecs.

At audio sample rates you will have very decent processing power per sample so the answer is pretty much yes to all questions on your list.

There are plenty of commercial libraries but also many free code examples. Don't expect free stuff to be plug and play toolbox so you are in for some learning both mathematically (designing filters, dealing with finite precision fixed point arithmetic) and progarammatically (learning DSP architecture and assembler programming). Proceed slowly, one thing at a time, from completion to perfection and full understanding Have fun.

I went ahead and ordered one as well. If it really is stand-alone, low-power, and 192 kHz, then this should be a lot of fun. With a built-in LCD display and two buttons, this opens up a lot of possibilities for a portable, easy-to-build, high-performance radio.

Has anyone else tried out TI's TMS320C5535 eZdsp development platform ? I've barely gotten past the setup procedure and run the
Audio Demo they included. I'm in a state of total confusion and don't have a clue as to what I've done so far, or what I should do next.

Most of the documentation centers around the "Code Composer Studio" program and technical details of the hardware components. It may presuppose an expert knowledge of machine-level programming, for all I can tell. Nothing I've found so far approaches a "TMS320C5535 eZdsp for Dummies" which clearly I need.

Maybe "TMS320C5535 eZdsp" and "Dummies" are mutually and permanently exclusive domains.

Or, maybe I've misunderstood what DSP is about. I'm looking for ways of filtering (high, low, bandpass, notch), noise suppression and other 'conditioning" of the audio signals out of my radios.

Can anyone set me straight ? Or even set me out in the direction for solving this problem ? I realize it will be a challenge, which is fine -- but is it even possible in my case ?

Many thanks, -Mike-

Mine arrived today. I haven't tried the software yet (it's bed time here) but I skimmed the quick start guide. If you're in total confusion about the audio demo, my understanding from reading the manual is that they just want to prove to you that the unit can receive digital data from the PC via USB port 1 and can convert that to analog audio output at the headphones. Similarly, the recording demo is to prove that the unit can also change analog data to digital, and pass that digital data back to the PC.

Presumably there must be a way to cause the unit to operate without a PC, by doing A/D conversion from the microphone, doing DSP on the chip, and converting the digital data back to analog at the headphone port, all without a PC.

The next steps in the manual appear to be aimed at making the development software (on the PC) able to transfer and cause execution of software (your DSP or user-interface code) from the PC development environment to the eZdsp hardware unit. The blinking LEDs indicate that the software (which probably is specifically written to do nothing other than blink the LEDs) was successfully compiled, transfered to the eZdsp, and executed on the eZdsp.

There is a TI wiki that I linked to earlier which may have more tutorials and samples.

By the way, I think this is a good deal at $55 USD. That price includes shipping, even to international locations. Mine was sent via FedEx from Texas to Japan.

Did anyone else receive yours yet?

Okay. I've exercised through the Quick Start Guide up through Section 7.0 "Running the C5535 eZdsp LED Blink Demostration." Everything acts/checks out as described. So, now what ?

I'm looking forward to "Adding DSP To Your High-Performance Crystal Set"!

73,

_________________

http://kr1s.kearman.com/
http://qrp.kearman.com/

My recommendation would be first to modify the blinking LED example in some way. Make the LEDs blink faster, or slower, or in a different sequence, or something. Then transfer your code to the eZdsp to make sure your changes are actually taking effect.

Next would be either to try writing a project from scratch (which will probably require a lot of study; for example, the application software and/or code build process apparently needs to worry about low-level issues like physical memory mapping), or to find a project similar to your needs (audio filtering) and try modifying that.

This directory contains a standalone demo that can be compiled, copied to the SD card, and booted and executed on the eZdsp without a PC.

C:\Program Files\Texas Instruments\ccsv4\emulation\boards\ezdsp5535_v1\boot_post_SDcard

Import the project into CCS and compile it. Then follow the instructions in this text file to create a bootable .bin file and copy that file to the SD card:

C:\Program Files\Texas Instruments\ccsv4\emulation\boards\ezdsp5535_v1\boot_post_SDcard\Creating_Bootable_Demo.txt

After copying the bootimg1.bin file to the SD card (and removing other .bin files), the device can be powered with an external USB power supply and will load and execute the code on the SD card.

One of the demos is an audio loopback that reads data from the microphone and plays it back to the headphones. This is probably a good starting point for writing filters. Read the data, do something to it, then write it out to the headphones.

Unfortunately the audio loopback demo isn't working quite right for me yet. I can hear the headphones pop as the DAC is unmuted, but I don't hear the microphone input on the headphones.

EDIT: The stand alone audio loopback demo is working now. It requires a line-level input at the stereo in jack, not a microphone-level input. (The corresponding source code file is named aic3204_loop_linein.c.) It's not clear to me yet how the sample rate is set, but anyway, the code is clearly reading data from the line in and writing data to the headphone out - which should be enough to stick a filter in-between.

EDIT 2: Looks like DSPLIB has a lot of filter-related functions. Combining the stand alone loopback demo and some functions from DSPLIB can probably go a long way towards making a software-enhanced/-defined radio. http://processors.wiki.ti.com/index.php/DSPLIB

Not that I'm in any way against discussing this gadget here, but you might draw in more users by starting a Yahoo group. Many users won't be into radio applications. Over time you could build a code library. But I would like to hear about your progress!

73,

_________________

http://kr1s.kearman.com/
http://qrp.kearman.com/

Done. For those interested, please join Yahoo group "eZsdr", accessible here:
http://groups.yahoo.com/group/eZsdr/

Let's see if we can start a community of interested users.