EA uniTFT Series

USB

The Universal Serial Bus is a serial bus system for interfacing a PC with other peripherals. It's based on differential data transfer. The bus topology is a strict master-slave communication (Exception: On the Go devices). In the case of EA uniTFT-Serie the PC/Master needs to coordinate the communication. The module has a CDC (Communications Device Class) and is found by Windows PC's as a virtual COM-Port:

To program the module, adjust settings or to perform initial tests, we recommend using the USB interface. It's easy to connect, the transfer rate is fast and no interface parameters need to be specified. The driver for Windows can be downloaded on our web-page: http://www.lcd-module.de/fileadmin/downloads/EA_CDCdriver_V5_2.zip

Besides the CDC mode, a Mass Storage Class implementation is also available (since V 1.2). If the module is started in this mode, the data on the SD Card can be edited directly.  In this mode, the module automatically connects to Windows as mass storage, like a normal USB storage device:

If the USB connection is not to be made via the mini-USB connector but via the primary connector, two solder bridges must be closed:

Attention:

A protocol has to be used in USB CDC mode. It's impossible to use the USB interface without a protocol, which means pin 22 (primary connector)  must not be set to GND. The high-speed connection of USB leads to buffer overflow, which are prevented by the protocol.