( SerialSend provides an easy alternative method of sending strings to whatever the highest numbered available COM port is, which can be very useful.) If you’re using a USB-to-serial converter, this number may change over time, especially if you plug the device into different USB sockets. You need to know the number of the COM port you want to send to.There are a couple of potential snags though: So the string “hello” gets sent to the serial port rather than to the screen. Here however, its output is redirected (using the “>” character) to the special filename “COM1”, which is actually a serial port rather than a file on disk. The echo command is typically used to display a string in the console. You can just type this command into a normal Windows console: The simplest case is something like the following which sends the string “hello” to COM1 (the first serial port). Instead you can just use Windows’ built-in echo, set and mode commands. I actually developed a small command line utility called SerialSend for doing exactly this, but in many cases you can get away without using any special programs at all. The sort of thing I might use this for is sending a command to a robot or other microcontroller-based device that I’m building using a USB-to-serial converter. I often need to send short character strings to a serial port in Windows.