This is a USB audio/GPIO interface board based on the common CM108 audio device. It is ideal for software modems (direwolf, QtSoundModem, Echolink, SvxLink, and more).

Having both audio in and out with breakout pads allows for easy construction of adaptor cables for most transceivers and doesn't require further modification.

Features:

• Dupont / Header cable compatible breakout pads for easy adaptor cable manufacture.
• Audio In / Out
• PTT trigger cable GPIO output
• SQL input detectable by software (as VOLDOWN USB event)
• Native drivers for most OS (recognised by Raspian, Windows, Linux, MacOS)
• MicroUSB interface

This is based on a previous design by Robin Olejnik, PCB redesigned by me to be easier to assemble and to build adaptor cables for.

I designed this as the existing method of modifying prebuilt cheap soundcards was awkward and relied on being able to patch SMD components into a commercial product.