title: Control of a program by use of Serial to-USB switch
body: <p>We want to control a program (written in VB) by pressing a switch attached to a serial to USB adapter. When pressed a certain function in the program will be activated. In order to achieve this we need to poll the relevant com port, continuously in the comm_event of the serial port and call the said function.  We tried by connecting a push button switch between the transmit and ground pins of the adapter, to change the state of the input buffer. It works sometimes, but misses most of the time. So it seems we need to create a long pulse train to keep the input buffer state last long enough to detect any change. Is there any gadget available for something like this? What kind of simple electronics can achieve this task.</p>
  
  <p>Any help will be highly appreciated.   </p>