Revision 2.1 Finalized

I’m officially finished with my university exams so its full steam ahead on my projects. I’ve just spent some time revising the PCB and I’ve added a new feature (which I desired from the beginning).

One of the biggest issues for me with the first version I made was the inability for the clock to register as a mass storage device to another device. This would allow users to view and edit the files on the clock such as configuration files and songs. Without this, the microSD card would need to be removed or custom software written, which I wanted to avoid.

To implement this, I added a CH334R USB C hub IC to expand the amount of USB devices the single USB C port could interact with, and also a MAX3421 to enable the microSD card to be communicated with via USB C as a mass storage device.

You might ask why I didn’t just use an ESP model that has this functionality, as there are editions that have mass storage capability, but I avoided them for the primary reason of them only supporting BLE (Bluetooth Low Energy) which does not allow for the device to be used as a speaker (an important feature for me).

The new schematic is attached, and an image of the new design is shown below.