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Electronics => Projects, Designs, and Technical Stuff => Topic started by: RoGeorge on November 16, 2024, 09:15:07 am

Title: CX20562-12Z Conexant USB CODEC from Plantronics .Audio 622 headset
Post by: RoGeorge on November 16, 2024, 09:15:07 am
Want to turn this Plantronics .Audio 622 headset into a USB soundcard for the lab.  The headset's USB connector was broken (in the picture it was on the left, already desoldered), but the board is still OK.  Works fine with a (long) USB cable attached instead of the PCB connector.

Main destination would be as an audio input, to monitor DIY audio circuits and experiments.  Couldn't find any datasheet or pinout for the CX20562-12Z chipset, only advertising flyers and block schematics.
https://www.electronicsdatasheets.com/download/120530.pdf?format=pdf (https://www.electronicsdatasheets.com/download/120530.pdf?format=pdf)

The PCB has additional unused pads near the pads used to solder the headset speaker and mic (on the right hand side in the picture), which I guess might be line-input.

The headset is recognized in Linux, but the soundcard control panel (in alsamixer) has no line-in volume and no other controls than volume.  Either it might need specific Linux drivers, or it might need specific jumpers/bytes in the configuration flash (on the PCB there is a ST 24C32 - 32kbit (4kB) - I2C EEPROM which I assume might contain configuration bytes).

I would like to reverse engineer the little PCB.  Anybody knows where I can get more info about the PCB, if not a schematic (found a schematic on electrotanya, but it's for CX20561-12Z, not for CX20562-12Z (not sure what the difference is), maybe the datasheet of the Conexant chipset, or at least the pinout for CX20562-12Z, please?