Convert the countless reams of digital information into analog signals using DAC104S085 and STM32G474RE
From digits to signals
Published Nov 08, 2024
Click board™
DAC 6 Click
Dev Board
Nucleo 64 with STM32G474RE MCU
Compiler
NECTO Studio
MCU
STM32G474RE
As digital information converges into analog clarity, our solution fosters connectivity by enabling effective communication between systems, unlocking a realm of data transformation possibilities
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Hardware Overview
How does it work?
DAC 6 Click is based on the DAC104S085, 10-bit resolution micro-power QUAD digital-to-analog converter with rail-to-rail output from Texas Instruments. The DAC104S085 is manufactured on a CMOS process with an architecture consisting of switches and resistor strings followed by an output buffer. The reference voltage is applied at the VREFIN pin and is shared by all four DAC outputs (A, B, C, and D). This string consists of 1024 equal-valued resistors with a switch at each junction of two resistors, plus a switch to the ground. The code loaded into the DAC register determines which switch is closed, connecting the proper node to the amplifier. The voltage reference pin of the DAC104S085 is not buffered, and because of that, it is recommended to drive the VREFIN pin by a voltage source with a low output impedance.
This is accomplished using the MCP1501, a low drift bandgap-based voltage reference from a Microchip capable of sinking and sourcing 20mA of current. The bandgap uses chopper-based amplifiers, effectively reducing the drift to zero. The reference voltage range which can be applied to the VREFIN pin is 1V to VCC (in this case, 2.048V), providing the widest possible output dynamic range with a maximum output current of 11mA per channel. The DAC 6 Click communicates with MCU using the 3-Wire SPI serial interface compatible with standard SPI, QSPI™, and MICROWIRE™ and operates at clock rates up to 40 MHz. To use the full dynamic range of the DAC104S085, it is possible to connect the VREFIN pin to the supply voltage VCC. Because of its low power consumption, a reference source may be
used as the reference input or the supply voltage, which results in accuracy and stability. The reference voltage level can be selected by positioning the SMD jumper labeled as VREF SEL to an appropriate position, selecting between a value of 2.048V and the supply voltage VCC. This Click Board™ uses the SPI communication interface with both 3.3V and 5V. The onboard SMD jumper labeled VCC SEL allows voltage selection for interfacing with 3.3V and 5V MCUs. More information about the DAC104S085’s functionality, electrical specifications, and typical performance can be found in the attached datasheet. However, the Click board™ comes equipped with a library that contains easy-to-use functions and a usage example that may be used as a reference for the development.
Features overview
Development board
Nucleo-64 with STM32G474R 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-M4
MCU Memory (KB)
512
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
128k
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
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo 64 with STM32G474RE MCU as your development board.
Track your results in real time
Application Output via Debug Mode
1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.
2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.
Software Support
Library Description
This library contains API for DAC 6 Click driver.
Key functions:
dac6_set_output- Function is used to set operation mode output channel and leveldac6_write_data- Sends 16-bit data to the device's input shift register.
Open Source
Code example
This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.
/*!
* \file
* \brief Dac6 Click example
*
* # Description
* DAC 6 click carries 12-bit buffered Digital-to-Analog Converter. It converts digital value
* to the corresponding voltage level using external voltage reference.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initalizes SPI driver.
*
* ## Application Task
* This example shows capabilities of DAC 6 click by changeing
* output values from 0 to the maximum output range on all four channels.
* Output voltage is calculated by using the equation :
* Vout = Vrefin * (set_out / 4095).
*
*
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "dac6.h"
// ------------------------------------------------------------------ VARIABLES
static dac6_t dac6;
static log_t logger;
static uint16_t n_cnt;
static float v_out;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
dac6_cfg_t cfg;
/**
* 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.
dac6_cfg_setup( &cfg );
DAC6_MAP_MIKROBUS( cfg, MIKROBUS_1 );
dac6_init( &dac6, &cfg );
}
void application_task ( void )
{
for ( n_cnt = 0; n_cnt < 4096; n_cnt += 315 )
{
dac6.chan = DAC6_CHANNEL_A;
dac6.op_mod = DAC6_WRITE_SPEC_UPDATE_OUTPUT;
dac6.v_ref = DAC6_V_REF_2048;
dac6.set_out = n_cnt;
v_out = dac6_set_output( &dac6 );
log_printf( &logger, " Channel A : VOUT ~ %.2f mV\r\n", v_out );
log_printf( &logger, "--------------------\r\n" );
Delay_ms( 5000 );
}
for ( n_cnt = 0; n_cnt < 4096; n_cnt += 315 )
{
dac6.chan = DAC6_CHANNEL_B;
dac6.op_mod = DAC6_WRITE_SPEC_UPDATE_OUTPUT;
dac6.v_ref = DAC6_V_REF_2048;
dac6.set_out = n_cnt;
v_out = dac6_set_output( &dac6 );
log_printf( &logger, " Channel B : VOUT ~ %.2f mV\r\n", v_out );
log_printf( &logger, "--------------------\r\n" );
Delay_ms( 5000 );
}
for ( n_cnt = 0; n_cnt < 4096; n_cnt += 315 )
{
dac6.chan = DAC6_CHANNEL_C;
dac6.op_mod = DAC6_WRITE_SPEC_UPDATE_OUTPUT;
dac6.v_ref = DAC6_V_REF_2048;
dac6.set_out = n_cnt;
v_out = dac6_set_output( &dac6 );
log_printf( &logger, " Channel C : VOUT ~ %.2f mV\r\n", v_out );
log_printf( &logger, "--------------------\r\n" );
Delay_ms( 5000 );
}
for ( n_cnt = 0; n_cnt < 4096; n_cnt += 315 )
{
dac6.chan = DAC6_CHANNEL_D;
dac6.op_mod = DAC6_WRITE_SPEC_UPDATE_OUTPUT;
dac6.v_ref = DAC6_V_REF_2048;
dac6.set_out = n_cnt;
v_out = dac6_set_output( &dac6 );
log_printf( &logger, " Channel D : VOUT ~ %.2f mV\r\n", v_out );
log_printf( &logger, "--------------------\r\n" );
Delay_ms( 5000 );
}
Delay_ms( 1000 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
