CH340 USB to TTL Serial Cable

CH340 is the new popular USB to UART converter/bridge for maker. It is being widely used in many development boards which includes:

• NodeMCU with CH340
• Maker UNO

This is a cable that embeds CH340 in it and extended the useful pins out to female headers.

The cable is the easiest way ever to connect to your microcontroller/WiFi router serial console port. Inside the big USB plug is the CH340 USB <-> Serial conversion chip and at the end of the 1-meter cable are four-wire:

• Red is power, or VCC, 5VDC
• Black is ground or 0V
• White is RXI input to USB's UART port, Receive input of USB's UART
• Green is TXO output of USB's UART port, Transmit output of USB's UART

The power pins provide 5V @ 500mA direct from the USB port and the RX/TX pins are 5.0V logic for interfacing with the most common 5V logic level chipsets.

Because of the separated pin headers, this cable is ideal for powering and connecting up to the debug/login console on the ESP32-CAM as ESP32's IO pins are 5V tolerant. We have tested this USB to UART converter with ESP32-CAM and it works fine.

This is easier to use than an FTDI cable in many cases because the wires are separated. Note that we call this a "TTL cable" (since that's what they're called) but technically it's CMOS logic.

It will appear as COM port after being plugged into the computer/laptop's USB port and after driver installation (1st and one time only).