Simplify data transfer between USB and UART devices with CP2110 and STM32F103RB
From USB to UART in a blink!
Published Oct 08, 2024
Click board™
USB UART 5 Click
Dev. board
Nucleo 64 with STM32F103RB MCU
Compiler
NECTO Studio
MCU
STM32F103RB
Revolutionize your data communication projects with the USB to UART magic – a compact and efficient solution that connects your devices swiftly and flawlessly.
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Hardware Overview
How does it work?
USB UART 5 Click is based on the CP2110, a single-chip HID USB to UART bridge controller from Silicon Labs. A USB function controller in the CP2110 is a USB 2.0-compliant, full-speed device with an integrated USB transceiver, one-time programmable ROM, and an asynchronous serial data bus (UART) in one compact package. The UART capabilities of the CP2110 include baud rate support from 300 to 1Mbps, hardware flow control, RS-485 support, and GPIO signals that are user-defined for status and control information. The USB function controller manages all data transfers between USB and UART, command requests generated by the USB host controller, and commands for controlling the function of the UARTs and GPIO pins. The CP2110 uses the standard USB HID device class, natively supported by most operating systems. A custom driver does
not need to be installed for this device. In addition, the CP2110 also supports USB Suspend and Resume modes for power management purposes. The CP2110 enters Suspend mode when Suspend signaling is detected on the bus using the SPD pin of the mikroBUS™ socket. Upon entering Suspend mode, the SPD signal is asserted, but it can also be asserted after a reset condition (RST pin) until device configuration during USB Enumeration is complete. SPD pin detects logic high level when the device is in the Suspend state and logic low when the device is in Normal mode, which is also visually indicated via red LED labeled as CONNECTED. This Click board™ also features 8 GPIO signals, located on unpopulated headers, that are user-defined for status and control information. Four GPIO signals support alternate features, including a configurable clock output
(CLK) from 24MHz to 47kHz, RS-485 transceiver control, and TX and RX LED toggle features. Also, the USB UART 5 Click can work in a USB-powered configuration thanks to the ability of the CP2110 to provide adequate power to all its parts with the help of an internal regulator using the USB bus voltage. To select this mode of operation, it is necessary to switch the jumper PWR SEL to the position marked with VBUS. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.
Features overview
Development board
Nucleo-64 with STM32F103RB MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M3
MCU Memory (KB)
128
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
20480
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo 64 with STM32F103RB MCU as your development board.
Track your results in real time
Application Output
1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.
2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.
3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.
Software Support
Library Description
This library contains API for USB UART 5 Click driver.
Key functions:
usbuart5_generic_write- USB UART 5 data writing function.usbuart5_generic_read- USB UART 5 data reading function.usbuart5_reset_device- USB UART 5 reset the device function.
Open Source
Code example
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.
/*!
* @file main.c
* @brief USB UART 5 Click Example.
*
* # Description
* This example reads and processes data from USB UART 5 Click board™.
* The library initializes and defines the UART bus drivers
* to transmit or receive data.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes driver, wake-up module, and performs the default configuration.
*
* ## Application Task
* Any data which the host PC sends via HidUartExample
* will be sent over USB to the click board and then it will be read and
* echoed back by the MCU to the PC where the terminal program will display it.
* Results are being sent to the UART Terminal, where you can track their changes.
*
* @note
* Make sure to download and install
* CP2110/4 Software package for Windows/Mac/Linux on the host PC.
*
* @author Nenad Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "usbuart5.h"
static usbuart5_t usbuart5;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
usbuart5_cfg_t usbuart5_cfg; /**< Click config object. */
/**
* Logger initialization.
* Default baud rate: 115200
* Default log level: LOG_LEVEL_DEBUG
* @note If USB_UART_RX and USB_UART_TX
* are defined as HAL_PIN_NC, you will
* need to define them manually for log to work.
* See @b LOG_MAP_USB_UART macro definition for detailed explanation.
*/
LOG_MAP_USB_UART( log_cfg );
log_init( &logger, &log_cfg );
log_info( &logger, " Application Init " );
// Click initialization.
usbuart5_cfg_setup( &usbuart5_cfg );
USBUART5_MAP_MIKROBUS( usbuart5_cfg, MIKROBUS_1 );
if ( UART_ERROR == usbuart5_init( &usbuart5, &usbuart5_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
usbuart5_default_cfg ( &usbuart5 );
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
char rx_data = 0;
if ( usbuart5_generic_read ( &usbuart5, &rx_data, 1 ) )
{
if ( usbuart5_generic_write ( &usbuart5, &rx_data, 1 ) )
{
log_printf( &logger, "%c", rx_data );
}
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
