X109 CM109 breadboard

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USB4IO home

A simple breadboard with some LED connected to the GPIO has been made in a weekend project (20100116). The USB CSOUNDU adapter audio adapter board has been used. It uses a C-Media CM109 codec. A general purpose PCB board has been cut to house and extend the original USB adapter board.

The audio connector has been removed from the original board and the board has been fitted into the extension board.

USB adapter board


cutted breadboard

desoldered audio jack

usb adpter fitted


8 LED have been connected via a 1k resistor to the GPIO1-8 pin of CM109 codec. Please notice that the PCB is very delicate and good SMD mounting skills are required.

The USB PCB board used has the pin 16 (GPIO5) connected to GND. It has been necessary to disconnect the pin from the PCB pad and to solder a wire directly to the IC pin. Pin 22 (GPIO8) pad has also required to be disconnect from ground.

The audio out jack return is originally connect to pin 31 (LOBS) DC 2.25V Output for Line Out Bias. We connected the jack return to ground and we inserted two 100uF-10V capacitors in series to audio left end right output.

Very thin wire from surplus relays coil has been used in wiring the board. Be very carefull in soldering the wires to the chip. Good SMD soldering skills are required here.



The breadboard fits into a plastic case and it can be used for software application development. Notice the free space left for future modification.