The circled IC in all the three Arduino Megas is the one which is responsible for USB Serial communication and Program Uploading Before you choose an Arduino Mega, you need to understand there are 3 different types of Mega versions related to USB interface and here they are
a) ATMega16U2 – Original Mega Compatible No additional Driver is needed.
b) CH340 – Additional Driver ch340 is needed.
c) CP2120 – Additional Driver Cp2102 is needed.
These additional drivers are needed to be installed only for one-time then there is no additional effort needed to use it.
TheCH340 driver chip is a USB converter chip, which converts USB to serial UART interface or to printer interface. In UART mode, CH340 provides common MODEM interface signals, to expand UART interface of computer or upgrade common serial communication devices to USB directly. The CH340 chip is used by a number of Arduino compatible boards NodeMCU and Some USB to TLL Converters to provide USB connectivity, you may need to install a driver to be able to detect your device to your PC. But don’t worry, it’s not that complicated as it sounds. Other Alternative to CH340 are CP2102 and FTDI. But the cost for these are more making your device costly. All three, Arduino UNO SMD, NodeMCU and USB to TTL converter, nearly get your work done.
Now here is the step by step illustration to install CH340 drivers on the Windows and Linux system.
Run the installer from the folder that you unzipped.
In the Arduino IDE when the CH340 is connected you will see a COM Port in the Tools > Serial Port menu, the COM number for your device may vary depending on your system.
Linux
Drivers are almost certainly built into your Linux kernel already and it will probably just work as soon as you plug it in. If not you can download the Linux CH340 Driver (but we’d recommend just upgrading your Linux install so that you get the “built in” one).
