USB UART 6 Click

How does it work?

USB UART 6 Click is based on the CP2102C, a USB-to-UART bridge from Silicon Labs and provides a simple way to convert USB signals to UART serial communication. By integrating a USB 2.0 full-speed function controller, USB transceiver, oscillator, and a Universal Asynchronous Receiver/Transmitter in a single package, the CP2102C eliminates firmware complexity and the need for external components, allowing engineers to add USB functionality to their applications with minimal development time. These features make USB UART 6 Click an ideal choice for upgrading RS-232 designs to USB and for use in a wide range of applications such as POS terminals, USB dongles, gaming controllers, medical equipment, and data loggers where high-speed USB-to-UART communication is essential.

Its integrated USB transceiver requires no external resistors and includes 512-byte transmit and receive buffers, while the internal 48MHz oscillator removes the need for an external crystal. The device supports USB 2.0 full-speed operation at 12Mbps, and standard CDC drivers are supported, eliminating the requirement for custom drivers and simplifying integration across multiple operating systems.

This Click board™ is designed in a unique format supporting the newly introduced MIKROE feature called "Click Snap." Unlike the standardized version of Click boards, this feature allows the main sensor/IC/module area to become movable by breaking the PCB, opening up many new possibilities for implementation. Thanks to the Snap feature, the CP2102C can operate autonomously by accessing its signals directly on the pins marked 1-8. Additionally, the Snap part includes a specified and fixed screw hole position, enabling users to secure the Snap board in their desired location.

This Click board™ establishes communication between the CP2102C module and the host MCU through a UART interface, using standard UART RX and TX pins and hardware flow control via CTS and RTS pins. The default communication speed is set at 115200bps, ensuring efficient data exchange. The board also has SUS yellow LED indicator that indicates when he CP2102C enters Suspend mode - when suspend signaling is detected on the bus. On entering Suspend mode, the CP2102C asserts the USB Suspend and Resume signals, for power management of both the CP2102C as well as external circuitry. Suspend signals are also asserted after a CP2102C reset until device configuration during USB Enumeration is complete.

Due to the limited space on the board, specifically within the Snap area, and in order to provide complete functionality and full access to the CP2102C signals, certain pins from the IC have been routed to an unpopulated 1x8 header. This allows designers to tap into additional features such as the reset signal, the USB suspend (SUS) signals, as well as the RI, DCD, DTR, and DSR modem control signals (ring indicator, data carrier detect, data terminal ready, and data set ready), ensuring that all critical control and status lines remain available for advanced configurations, debugging, and custom application requirements. To manage the operation of the CP2102C IC, USB UART 6 Click integrates the MAX40200 from Analog Devices that enables or disables the sensor through the EN pin.

This Click board™ can operate only with a 3.3V logic voltage level. In addition, selecting the logic voltage source is also available via the VIO SEL jumper located in the Snap section. Using this jumper, the user can choose between the 3.3V mikroBUS power rail or an externally supplied voltage fed through the VDD header within the 3V to 3.6V range, ensuring flexibility with various system power configurations. The Snap section also features a VRG SEL jumper that allows selecting the power source for the IC’s internal 5V voltage regulator.

When the internal regulator is used and the USB connection is active (self-powered mode), the VDD pin provides an output voltage of 3.3V, enabling access to the regulated supply for external use or monitoring. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. It also comes equipped with a library containing functions and example code that can be used as a reference for further development.

Click Snap

Click Snap is an innovative feature of our standardized Click add-on boards, designed to bring greater flexibility and optimize your prototypes. By simply snapping the PCB along predefined lines, you can easily detach the main sensor/IC/module area, reducing the overall size, weight, and power consumption - ideal for the final phase of prototyping. For more details about Click Snap, visit the official page dedicated to this feature.

Specifications

Pinout diagram

This table shows how the pinout on USB UART 6 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	NC
Device Enable / ID SEL	EN	2	RST	INT	15	RTS	UART RTS
UART CTS / ID COMM	CTS	3	CS	RX	14	TX	UART TX
	NC	4	SCK	TX	13	RX	UART RX
	NC	5	MISO	SCL	12	NC
	NC	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

USB UART 6 Click electrical specifications

Software Support

USB UART 6 Click demo application is developed using the NECTO Studio, ensuring compatibility with mikroSDK's open-source libraries and tools. Designed for plug-and-play implementation and testing, the demo is fully compatible with all development, starter, and mikromedia boards featuring a mikroBUS™ socket.

Example Description

This example demonstrates the USB UART 6 Click board's ability to act as a USB-to-UART bridge. It enables bidirectional communication between a USB host and a UART device by forwarding received data between the USB and UART interfaces.

Key Functions

• usbuart6_cfg_setup This function initializes Click configuration structure to initial values.
• usbuart6_init This function initializes all necessary pins and peripherals used for this Click board.
• usbuart6_generic_write This function writes a desired number of data bytes by using UART serial interface.
• usbuart6_generic_read This function reads a desired number of data bytes by using UART serial interface.
• usbuart6_enable_device This function enables the device by setting the EN pin to high logic state.

Application Init

Initializes the logger and the Click board and enables the device.

Application Task

Continuously reads the data from one UART interface and forwards it to the other, enabling seamless USB to UART data transfer and vice versa.

Application Output

This Click board can be interfaced and monitored in two ways:

• Application Output - Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.
• UART Terminal - Monitor data via the UART Terminal using a USB to UART converter. For detailed instructions, check out this tutorial.

Additional Notes and Information

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.