Mega-mini USB module

To make the serial ports on the Mega mini MPI more useful.  I plan on designing several modules that will connect to the UART header on the side for connection to other devices.

The first of these is a dual USB serial bridge module that will allow direct connection via a USB cable to a modern Mac or PC for a hi-speed serial connection.

They use an FT232 serial USB to UART bridge IC, which I chose because of it’s capabilities, ease of use, and it’s good driver support for modern OSes.

IMG_20190117_165940Mega mini USB module, assembled prototype

Connection speeds of up to 921600 baud are supported, with some initial tests showing sustained transfer rates on the CoCo of 52KB per second at .89MHz on a CoCo2, and 78KB per second on a CoCo3 at 1.79MHz.

IMG_20190118_143827IMG_20190118_174741.89MHz transfer test at top, 1.79MHz at bottom

You can see the prototype module connected to the Mega mini in this next picture.  I need to design a 3d printed case for the module soon to bring it all together.

IMG_20190117_170300.jpgModule in Mega mini UART port

REV02.pngREV02, likely the final design

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