Unleash the beauty of analog side of a signal with DAC60508 and PIC18LF47K40

Bridging the binary abyss

Published Aug 21, 2023

Click board™

DAC 12 Click

Dev. board

EasyPIC v8

Compiler

NECTO Studio

MCU

PIC18LF47K40

Convert discrete digital values into continuous analog voltages, and enable accurate audio or visual signal representation

Hardware Overview

How does it work?

DAC 12 Click is based on the DAC60508, a low-power voltage-output 8-channel 12-bit digital-to-analog converter (DAC) from Texas Instruments. Each output channel in the DAC60508 consists of an R-2R ladder architecture, followed by an output buffer amplifier. It also includes a 2.5V, 5ppm/°C internal reference, eliminating the need for an external precision reference in most applications, and a user interface-selectable gain configuration that provides full-scale output voltages of 1.25V, 2.5V, or 5V. This Click board™ communicates with MCU through a flexible serial interface compatible

with SPI-type interfaces used on many microcontrollers and DSP controllers, with a maximum frequency of 50 MHz. The input data are written to the individual DAC data registers in straight binary format, where after a Power-On or a reset event, all DAC registers are set to a mid-scale code. Data written to the DAC data registers are initially stored in the DAC buffer registers. Data transfer from the DAC buffer registers to the active DAC registers can be configured immediately using the asynchronous mode or initiated by an LDAC trigger in synchronous mode. Once the DAC

active registers are updated, the DAC outputs change to new values. When the host reads from a DAC data register, the value held in the DAC buffer register is returned (not stored in the DAC active register). 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.

Features overview

Development board

EasyPIC v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports many high pin count 8-bit PIC microcontrollers from Microchip, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer. 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, EasyPIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the EasyPIC v8 development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board 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 DEVICE, and CAN are also included, including the well-established mikroBUS™ standard, two display options (graphical and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from the smallest PIC MCU devices with only eight up to forty pins. EasyPIC 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.

Microcontroller Overview

MCU Card / MCU

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

3728

Used MCU Pins

mikroBUS™ mapper

RST

SPI Chip Select

RE0

SPI Clock

RC3

SCK

SPI Data OUT

RC4

MISO

SPI Data IN

RC5

MOSI

Power Supply

3.3V

Ground

GND

PWM

INT

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

EasyPIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v8 as your development board.

NECTO Output Selection Step Image hardware assembly

In the advanced settings, pay special attention to the Redirect standard output field. By default, it is set to Application output as the method of displaying final results. To show results via a UART terminal, select the “UART” option in that field and click the “SAVE” button. You will be returned to the Compiler field, and now you can move on to the next step by pressing the “NEXT” button.

GNSS2 Click front image hardware assembly

GNSS2 Click complete accessories setup image hardware assembly

EasyPIC v8 Access DIPMB 1 - upright/background hardware assembly

NECTO Compiler Selection Step Image hardware assembly

Necto DIP image step 7 hardware assembly

Software Support

Library Description

This library contains API for DAC 12 Click driver.

Key functions:

dac12_soft_reset - This function executes the software reset command
dac12_set_channel_value - This function sets the raw DAC value to the specific channels output
dac12_set_channel_voltage - This function sets the output voltage of the specific channels

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 DAC12 Click example
 *
 * # Description
 * This example demonstrates the use of DAC 12 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 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.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "dac12.h"

#define NUMBER_OF_STEPS    20  // The number of steps by which the entire voltage range will be divided. 

static dac12_t dac12;
static log_t logger;

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    dac12_cfg_t dac12_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.
    dac12_cfg_setup( &dac12_cfg );
    DAC12_MAP_MIKROBUS( dac12_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == dac12_init( &dac12, &dac12_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    DAC12_SET_DATA_SAMPLE_EDGE;
    
    if ( DAC12_ERROR == dac12_default_cfg ( &dac12 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
    float step = DAC12_INTERNAL_VREF / NUMBER_OF_STEPS;
    float output_voltage = step;
    for ( uint8_t cnt = 0; cnt < NUMBER_OF_STEPS; cnt++ )
    {
        if ( DAC12_OK == dac12_set_channel_voltage ( &dac12, DAC12_SELECT_CHANNEL_ALL, output_voltage ) )
        {
            log_printf( &logger, " All channels output voltage set to %.3f V\r\n", output_voltage );
            output_voltage += step;
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
        }
    }
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

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