Create fast and reliable signal conversions with AD3541R and STM32F091RC
Convert digital data into an analog signal
Published Feb 26, 2024
Click board™
DAC 13 Click
Dev. board
Nucleo-64 with STM32F091RC MCU
Compiler
NECTO Studio
MCU
STM32F091RC
Highly accurate digital-to-analog conversion
A
A
Hardware Overview
How does it work?
DAC 13 Click is based on the AD3541R, a single channel, 16-bit, 16-MUPS voltage output DAC from Analog Devices, with programmable output ranges. It uses a current-steering DAC architecture with a reference voltage of 2.5V (internal but also with the possibility of an external reference voltage supplied on the VREF header), where DAC current is converted to a voltage through an internal transimpedance amplifier (TIA). The AD3541R also features multiple error-checkers in analog and digital domains to guarantee safe operation in various applications such as data acquisition systems, process control equipment, and many more.The AD3541R has five pre-configured output voltage ranges: 0V to 2.5V; 0V to 5V; 0V to 10V; -5V to +5V; and -2.5V to +7.5V. The selection of the output range requires a combination of register configurations and a given transimpedance gain (x1 or x2 Output Gain jumper position). These drift-compensating feedback resistors, or transimpedance gain, for the internal TIA, scale the output voltage.
The supply for the TIA, integrated into AD3542R, must be adjusted depending on the selected output span. In addition to the internal TIA supply, the user is provided with the possibility of an external trans-impedance amplifier supply on the connector marked with VEXT. Selection can be performed by an onboard SMD jumper labeled as Output Amp Voltage by placing it in an appropriate position marked as INT or EXT. This Click board™ communicates with MCU through a versatile SPI interface capable of operating in classic and dual SPI modes with a single or double data rate. The AD3541R has two update modes offering maximum speed and maximum accuracy, synchronously or asynchronously. A synchronous update occurs when the change of the DAC output is triggered by an external LDC signal routed to the AN pin of the mikroBUS™ socket, which with its low state, causes the DAC register to update if the input register has new data, Otherwise, the DAC automatically updates when new data is written to the input register
(LDC high). An asynchronous update occurs when the change of the DAC output follows an operation on the register set. The AD3541R also possesses an additional interrupt alert signal, routed on the INT pin of the mikroBUS™ socket labeled as ALT, indicating abnormal conditions both in the analog and digital domains, and general reset function routed on the RST pin of the mikroBUS™ socket. The ALT pin is also set after reset and in case of initialization failure. This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. A logic voltage level conversion is performed by an appropriate voltage level translator, while an onboard LDO, the AP2112, ensures recommended supply voltage level to power the AD3541R. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.
Features overview
Development board
Nucleo-64 with STM32F091RC 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-M0
MCU Memory (KB)
256
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
32768
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 STM32F091RC 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 DAC 13 Click driver.
Key functions:
dac13_set_output_rangeThis function sets the output voltage range and the @b ctx->v_zero_scale and @b ctx->v_full_scale variables for the selected range.dac13_set_dac_valueThis function sets the raw DAC value.dac13_set_output_voltageThis function sets the DAC output voltage.
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 DAC 13 Click example
*
* # Description
* This example demonstrates the use of DAC 13 click board by changing
* the outputs voltage level every 2 seconds.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs the click default configuration.
*
* ## Application Task
* Changes the output voltage every 2 seconds and logs the voltage value on the USB UART.
* It will go through the entire voltage range taking into account the number of steps
* which is defined below.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "dac13.h"
#define NUMBER_OF_STEPS 20 // A number of steps by which the entire voltage range will be divided, must be >= 1.
static dac13_t dac13;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
dac13_cfg_t dac13_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.
dac13_cfg_setup( &dac13_cfg );
DAC13_MAP_MIKROBUS( dac13_cfg, MIKROBUS_1 );
if ( SPI_MASTER_ERROR == dac13_init( &dac13, &dac13_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( DAC13_ERROR == dac13_default_cfg ( &dac13 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float step = ( dac13.v_full_scale - dac13.v_zero_scale ) / ( NUMBER_OF_STEPS - 1 );
float out_voltage = dac13.v_zero_scale;
for ( uint8_t cnt = 0; cnt < NUMBER_OF_STEPS; cnt++ )
{
if ( DAC13_OK == dac13_set_output_voltage ( &dac13, out_voltage ) )
{
log_printf ( &logger, " Output voltage : %.2f V\r\n\n", out_voltage );
out_voltage += step;
Delay_ms ( 2000 );
}
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
