The Digispark Programming Tool is a USB switch with a female USB connector on one end, a proper male connector on the other, and a switch on the USB 5v power connection.
Being able to switch the Digispark on and off when plugged into USB (using USB power) allows you to quickly disconnect and reconnect the Digispark when programming, debugging, etc without having to physically disconnect it. In addition to being quicker, this reduces wear on the connectors, and the real connectors present on the programming tool provide a solid connection between the PC and Digispark.
We've also added a red LED that turns on when the USB line is switched off. This reminds your that your device is currently disconnected - saving you from wondering why it isn't working!

The LED can be left off the board for those who do not want the indicator.
This can be used for any USB powered device - we've tested it with many, though it may not be technically compliant with all devices and standards.
Note:

This is an unassembled kit and requires basic soldering. This is designed for use with the Digispark development board, which is not included.
Schematics, source files, software, and datasheets are provided rovided "as is", without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and noninfringement. in no event shall the authors or copyright holders be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with the product or the use or other dealings in these products.

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