Added a part about USB-UART interfaces that support 3.3V and 5V

content/docs/wiki/cc3200/debug-port.md

@@ -53,6 +53,9 @@ SOP2 (pin 9) high will activate the UART load mode to flash the system during de
 # Extract Firmware
 ## Introduction
 Grab your favourite USB-UART **3.3V** interface, recommending those with DTR or RTS port to automate board reset. You may also use a CC3200 Launchpad, but then you will need to reset it by hand. SOP2 need to be pulled high while reset to set the cc3200 into UART-Mode.
+You may have a UART to USB adapter that supports both 3.3V and 5V. In this case you should find a jumper on the board to select the correct mode. You can see examples of such jumpers here (but there are others.) **In any case, make absolutely sure that 3.3V (often labelled 3v3) is set!**
+
+![/img/uart_3v3-5V_jumper_black.jpg](/img/uart_3v3-5V_jumper_black.jpg) ![/img/uart_3v3-5V_jumper_switch.jpg](/img/uart_3v3-5V_jumper_switch.jpg) ![/img/uart_3v3-5V_jumper_yellow.jpg](/img/uart_3v3-5V_jumper_yellow.jpg)
 
 ## Toolset
 Use [cc3200tool](https://github.com/toniebox-reverse-engineering/cc3200tool) to extract the firmware. Just download it to your favorite location.