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Transmitter beginnings

A project log for HQ Wireless Audio

I don't want to pay $200, when i can pay $250 and learn something. Wireless audio by someone who doesn't know anything about it.

zacnoteszacnotes 01/01/2015 at 04:450 Comments

First draft of the schematic and board (just to get an idea of how small I can go, and to attempt to work out the details regarding the PCB antenna.

Schematic first run:

PCB first run:

All done in Diptrace. The DRC error circles are all related to the antenna, it is a part created of shapes on the signal plane, using the dimensions for the TI inverted F antenna. I couldn't figure out how to make it see all the shapes as one piece, either in the part creator or the PCB layout, so if anyone has any tips regarding that, I would happily utilize them. I know that it is missing some passive components yet and a couple of the parts on there are just placeholders for the moment, so the next step is fine tuning the schematic, adding all the passives and replacing parts with the ones I intend on using. I will probably completely re-do the PCB layout as well, I think it can be smaller. Currently it comes in at about 43.5mm x 29.5mm. I will likely make it the width of the antenna, and drop everything under that. They aren't labeled on this layout, but U1 is the CC8502 wireless chip, and U2 is the codec.

Diptrace Schematic

Diptrace PCB

I have also gone through all options for the programming of the unit, the PurePath Wireless Programmer software from TI is really easy to use, it limits all options based on which chip you select, and what role you want it to play. Many of the options in the software affect what pins you use, so it was a good thing I was thorough.

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