Description

YKUSH boards allow the user to selectively switch ON and OFF the power of each of the USB devices connected to the Hub downstream ports. The control is done using an application in the host system (e.g., PC to which the YKUSH board is connected). Switching ON/OFF a YKUSH downstream port with a device connected to it has the same effect than physically Connecting/Disconnecting a Device to a port of a typical USB hub.

The switching control is performed by sending commands to the on-board microcontroller (YKUSH board control unit), which is seen by host as a HID USB device not requiring the installation of specific drivers. The communication between the host and the board control unit is based on a simple message protocol. The communication protocol is documented and detailed in the Product Manual available for download bellow, in the Documents and Resources section.

A control application is also available for download bellow, in the Documents and Resources section. This application implements all commands and functionality currently supported by YKUSH boards. It's a fully functional command line console application that can be used as-is or as a base for user development of own applications.

The control application is made available for Linux and Windows operating systems. Nonetheless it uses cross-platform libraries which facilitates porting the application source code to be built in other operating systems. The software is distributed as open source. For Windows a pre-built executable is also available for download.

The board performs the power switching of the downstream ports by switching the VBUS lines. For some self-powered USB devices (USB devices that use an external power supply to draw power) the additional switching of the data-lines may be required to fully disconnect the device. For these cases please check the YKUSH 3 board.

Application Example

Consider the scenario of a home server DIY implementation. One of the functions of this system is to perform daily backups of the household computers.

With YKUSH the home server is able to switch ON and OFF the USB external HDD drives, effectively powering them ON/OFF. This way it is ensured that the drives are only powered when they are being used to backup data enabling a higher longevity of the drives and lower power consumption.

Technical Specifications

Applications

Target applications include enhanced high speed USB Hubs, power/activity controllers for Network Area Storage systems (NAS's), enhanced USB Hub with individual port switching for Home Servers, power switching for USB powered devices.