Intermediate
30 min
0

Convert digital data streams into analog signals with DAC8554 and ATmega3250

Where data shapes analog potential

DAC 8 Click with UNI-DS v8

Published Aug 19, 2023

Click board™

DAC 8 Click

Development board

UNI-DS v8

Compiler

NECTO Studio

MCU

ATmega3250

Experience the synergy of precision and transformation with our DAC solution

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Hardware Overview

How does it work?

DAC 8 Click is based on the DAC8554, a 16-bit QUAD channel, ultra-low glitch, voltage-output digital to analog converter from Texas Instruments. It offers good linearity, exceptionally low glitch, and high precision output amplifier, allowing rail-to-rail output swing over a wide supply voltage range. This component additionally has a Power-On reset function, which ensures that DAC outputs power-up at zero-scale and remains there until a proper write operation occurs. Also, it provides a power-down feature that reduces the current consumption to 175nA per channel. An external voltage reference is made user-programmable to achieve a fully flexible range of the DAC8554. For this purpose, the Click board™ uses another DAC, DAC60501, a 12-bit DAC from Texas Instruments, whose output is brought to the

VREF pin of the DAC8554. That way, the reference voltage of the DAC8554 can be set at any value between 0V and 5V, providing high precision and low power consumption as well. That makes the DAC 8 Click a fully customizable solution, well suited for applications where the maximum precision from the output 16-bit DAC is needed. DAC60501 uses the I2C serial interface to communicate with the MCU and operates at a clock rate of up to 100kHz. 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 50 MHz. Additional functionality, such as software simultaneous update capability, is implemented and routed at the PWM pin of the mikroBUS™, which allows when new data enter

the device, all DAC outputs can be updated simultaneously and synchronously with the clock. It also possesses enable function routed at the CS pin of the mikroBUS™ that is used to connect the SPI interface to the serial port. This Click Board™ is designed to be operated with both 3.3V and 5V logic levels. The onboard SMD jumper labeled VCC SEL allows voltage selection for interfacing with 3.3V and 5V MCUs. More information about the DAC8554’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 can be used as a reference for the development.

DAC 8 Click top side image
DAC 8 Click bottom side image

Features overview

Development board

UNI-DS v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different STM32, Kinetis, TIVA, CEC, MSP, PIC, dsPIC, PIC32, and AVR MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, UNI-DS v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the UNI-DS v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART, USB

HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. UNI-DS v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

UNI-DS v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

AVR

MCU Memory (KB)

32

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

2048

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
SPI Enable
PG0
RST
SPI Chip Select
PG1
CS
SPI Clock
PB1
SCK
SPI Data OUT
PB3
MISO
SPI Data IN
PB2
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Software Update
PB4
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PE4
SCL
I2C Data
PE5
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

DAC 8 Click Schematic schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI-DS v8 as your development board.

Fusion for PIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
v8 SiBRAIN Access MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

Track your results in real time

Application Output

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

UART Application Output Step 1

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

UART Application Output Step 2

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

UART Application Output Step 3

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART Application Output Step 4

Software Support

Library Description

This library contains API for DAC 8 Click driver.

Key functions:

  • dac8_device_config - This function set configuration of the DAC8554

  • dac8_load_dac - This function simultaneously update DAC with the contents of the corresponding data buffers

  • dac8_set_vref - This function set voltage reference

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 Dac8 Click example
 * 
 * # Description
 * This 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 
 * Initialization driver enables - I2C.
 * Configure DAC60501: executes call software reset, disable sync and internal reference and 
 * disable Power-down mode, the set reference voltage is internally divided by a factor of 2,
 * amplifier for corresponding DAC has a gain of 2.
 * Initialization driver enables - SPI, enable DAC8554, also write log.
 * 
 * ## Application Task  
 * This is an example that demonstrates the use of the DAC 8 Click board.
 * DAC 8 board changeing output values:
 * Channel A ~ 2500 mV, Channel B ~ 1250 mV,
 * Channel C ~  625 mV, Channel D ~  312 mV.
 * All data logs write on USB uart changes every 5 sec.
 * 
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "dac8.h"

// ------------------------------------------------------------------ VARIABLES

static dac8_t dac8;
static log_t logger;

dac8_cfg_data_t cfg_dac;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    dac8_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.

    dac8_cfg_setup( &cfg );
    DAC8_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    
    dac8_init( &dac8, &cfg, DAC8_MASTER_I2C );

    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, "  I2C driver init.   \r\n" );
    Delay_ms( 100 );

    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, "      DAC60501       \r\n" );
    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, "     Soft reset      \r\n" );
    dac8_soft_reset( &dac8 );
    Delay_ms( 100 );

    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, "  Disable sync. mode \r\n" );
    dac8_enable_sync( &dac8, DAC8_SYNC_DISABLE );
    Delay_ms( 100 );

    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, "    Set config.:     \r\n" );
    log_printf( &logger, " Enable:             \r\n" );
    log_printf( &logger, " Internal reference  \r\n" );
    log_printf( &logger, " Disable:            \r\n" );
    log_printf( &logger, " Power-down mode     \r\n" );
    dac8_set_config( &dac8, DAC8_CONFIG_REF_PWDWN_ENABLE, DAC8_CONFIG_DAC_PWDWN_DISABLE );
    Delay_ms( 100 );
    
    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, "  Vref divided by 2  \r\n" );
    log_printf( &logger, "  Set DAC gain of 2  \r\n" );
    dac8_set_gain( &dac8, DAC8_GAIN_REF_DIV_2, DAC8_GAIN_BUFF_GAIN_1 );
    Delay_ms( 100 );

    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, " Set Vref ~ 2500 mV  \r\n" );
    dac8_set_vref( &dac8, 2500 );
    Delay_ms( 1000 );

    dac8_init( &dac8, &cfg, DAC8_MASTER_SPI );
    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, "  SPI driver init.   \r\n" );
    Delay_ms( 1000 );
    
    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, "       DAC8554       \r\n" );
    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, "    Enable DAC8554   \r\n" );
    dac8_device_enable( &dac8, DAC8_DAC8554_ENABLE );
    Delay_ms( 100 );
}

void application_task ( void )
{
    log_printf( &logger, "---------------------\r\n" );
    
    cfg_dac.addr = DAC8_ADDR_DEFAULT;
    cfg_dac.ctrl_upd_an_out = DAC8_CTRL_UPD_AN_OUT_SINGLE_CH_STORE;
    cfg_dac.dac_sel = DAC8_DAC_SEL_CH_A;
    cfg_dac.pwr_mode = DAC8_PWR_MODE_POWER_UP;
    cfg_dac.dac_val = 0xFFFF;
    
    log_printf( &logger, " Channel A ~ 2500 mV \r\n" );
    dac8_device_config( &dac8, cfg_dac );
    dac8_load_dac(  &dac8 );
    Delay_ms( 5000 );
    
    log_printf( &logger, "---------------------\r\n" );

    cfg_dac.addr = DAC8_ADDR_DEFAULT;
    cfg_dac.ctrl_upd_an_out = DAC8_CTRL_UPD_AN_OUT_SINGLE_CH_STORE;
    cfg_dac.dac_sel = DAC8_DAC_SEL_CH_B;
    cfg_dac.pwr_mode = DAC8_PWR_MODE_POWER_UP;
    cfg_dac.dac_val = 0x7FFF;

    log_printf( &logger, " Channel B ~ 1250 mV \r\n" );
    dac8_device_config(  &dac8, cfg_dac );
    dac8_load_dac( &dac8 );
    Delay_ms( 5000 );
    
    log_printf( &logger, "---------------------\r\n" );
    
    cfg_dac.addr = DAC8_ADDR_DEFAULT;
    cfg_dac.ctrl_upd_an_out = DAC8_CTRL_UPD_AN_OUT_SINGLE_CH_STORE;
    cfg_dac.dac_sel = DAC8_DAC_SEL_CH_C;
    cfg_dac.pwr_mode = DAC8_PWR_MODE_POWER_UP;
    cfg_dac.dac_val = 0x3FFF;

    log_printf( &logger, " Channel C ~  625 mV \r\n" );
    dac8_device_config(  &dac8, cfg_dac );
    dac8_load_dac( &dac8 );
    Delay_ms( 5000 );
    
    log_printf( &logger, "---------------------\r\n" );

    cfg_dac.addr = DAC8_ADDR_DEFAULT;
    cfg_dac.ctrl_upd_an_out = DAC8_CTRL_UPD_AN_OUT_SINGLE_CH_STORE;
    cfg_dac.dac_sel = DAC8_DAC_SEL_CH_D;
    cfg_dac.pwr_mode = DAC8_PWR_MODE_POWER_UP;
    cfg_dac.dac_val = 0x1FFF;

    log_printf( &logger, " Channel D ~  312 mV\r\n" );
    dac8_device_config(  &dac8, cfg_dac );
    dac8_load_dac(  &dac8 );
    Delay_ms( 5000 );
}

void main ( void )
{
    application_init( );

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

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

Additional Support

Resources