Intermediate
30 min

Empower your systems with DAC128S085 and STM32L073RZ

Where bits find their voice in the form of analog voltage

DAC 11 Click with Nucleo-64 with STM32L073RZ MCU

Published Feb 26, 2024

Click board™

DAC 11 Click

Dev. board

Nucleo-64 with STM32L073RZ MCU

Compiler

NECTO Studio

MCU

STM32L073RZ

From sensors to control circuits, this solution bridges the gap between digital data and analog actions, enhancing your ability to drive insights

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Hardware Overview

How does it work?

DAC 11 Click is based on the DAC128S085, a general-purpose 12-bit 8-channel digital-to-analog converter (DAC) from Texas Instruments. The DAC128S085 is fabricated on a CMOS process with an architecture that consists of switches and resistor strings followed by an output buffer. It ensures monotonicity, low power consumption of 4.85mW at 5V, individual channel power-down capability, and has high precision output amplifier that allows rail-to-rail output swing over a wide supply voltage range. DAC architecture consists of 4096 equal-valued resistors with a switch at each junction of two resistors, plus a switch to ground. The code loaded into the DAC register determines

which switch is closed, connecting the right node to the amplifier. Because all eight channels of the DAC128S085 can be controlled independently, each consists of a DAC register and a 12-bit DAC. Depending on the mode of operation, data written into a DAC register causes the 12-bit DAC output to be updated, or an additional command is required to update the DAC output. Also, a Power-On reset circuit ensures that the DAC outputs power up to zero volts and remains there until there is a valid write to the device. The DAC 11 Click communicates with MCU using the SPI serial interface compatible with standard QSPI, MICROWIRE, and DSP interfaces, with a maximum

frequency of 50 MHz. Also, this Click board™ is designed to utilize the entire dynamic range of DAC128S085 by having all power supply pins (and reference voltage pins) connected, sharing the same supply voltage. In addition, the user can further use the RC filter at the output to roll off output noise. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this 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.

DAC 11 Click top side image
DAC 11 Click bottom side image

Features overview

Development board

Nucleo-64 with STM32L073RZ 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.

Nucleo 64 with STM32L073RZ MCU double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M0

MCU Memory (KB)

192

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.

Click Shield for Nucleo-64 accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
SPI Chip Select
PB12
CS
SPI Clock
PB3
SCK
SPI Data OUT
PB4
MISO
SPI Data IN
PB5
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

DAC 11 Click Schematic schematic

Step by step

Project assembly

Click Shield for Nucleo-64 accessories 1 image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo-64 with STM32L073RZ MCU as your development board.

Click Shield for Nucleo-64 accessories 1 image hardware assembly
Nucleo 64 with STM32F401RE MCU front image hardware assembly
LTE IoT 5 Click front image hardware assembly
Prog-cut hardware assembly
LTE IoT 5 Click complete accessories setup image hardware assembly
Nucleo-64 with STM32XXX MCU Access MB 1 Mini B Conn - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Clicker 4 for STM32F4 HA MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

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 11 Click driver.

Key functions:

  • dac11_write_control_reg - This function writes data to a single control register by using SPI serial interface

  • dac11_set_all_ch_voltage - This function sets the output voltage of all channels depending on the vref value

  • dac11_set_specific_ch_voltage - This function sets the output voltage of the specific channels depending on the vref value

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 DAC11 Click example
 *
 * # Description
 * This example demonstrates the use of DAC 11 click board.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and executes the click default configuration which sets the WRM mode and
 * disables all outputs.
 *
 * ## Application Task
 * Changes the output voltage of all channels 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.
 *
 * @note
 * Measure the voltage at VCC_SEL jumper and adjust the reference voltage value below for better accuracy.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "dac11.h"

#define REFERENCE_VOLTAGE  3.3 // The reference voltage defined by the VCC_SEL on-board jumper. 
#define NUMBER_OF_STEPS    20  // The number of steps by which we will divide the entire voltage range. 

static dac11_t dac11;
static log_t logger;

void application_init ( void )
{
    log_cfg_t log_cfg;      /**< Logger config object. */
    dac11_cfg_t dac11_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 );
    Delay_ms( 100 );
    log_info( &logger, " Application Init " );

    // Click initialization.

    dac11_cfg_setup( &dac11_cfg );
    DAC11_MAP_MIKROBUS( dac11_cfg, MIKROBUS_1 );
    err_t init_flag  = dac11_init( &dac11, &dac11_cfg );
    if ( SPI_MASTER_ERROR == init_flag )
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    dac11_default_cfg ( &dac11 );
    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
    float step = REFERENCE_VOLTAGE / NUMBER_OF_STEPS;
    float output_voltage = step;
    uint8_t cnt = 0;
    while ( cnt < NUMBER_OF_STEPS )
    {
        dac11_set_all_ch_voltage ( &dac11, REFERENCE_VOLTAGE, output_voltage );
        log_printf( &logger, " All channels output voltage set to %.2f V\r\n", output_voltage );
        
        output_voltage += step;
        cnt++;
        Delay_ms( 2000 );
    }
}

void main ( void )
{
    application_init( );

    for ( ; ; )
    {
        application_task( );
    }
}

// ------------------------------------------------------------------------ END

Additional Support

Resources

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