View source for Control an LED via USB/RS232 adapter

Today I connected my [http://www.linuxintro.org/wiki/Usb-rs232-adapter USB to serial adapter] to my computer. Then I looked up which pin is TXD and which is GND. Then I used python's serial library to switch on TXD, connected TXD to GND and the result can be seen here:

[[File:Led-on-rs232.png]]

Why does this work? Because there is a limiter that limits the power so the LED does not break.