Intermediate
30 min

The best available custom ADC solution with ADS131M02 and PIC18F57Q43

Go digital with ADC!

ADC 15 Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

ADC 15 Click

Dev Board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

Discover what our advanced ADC can do for your engineering solutions – check it out now!

A

A

Hardware Overview

How does it work?

ADC 15 Click is based on the ADS131M02, a low-power, two-channel, simultaneously sampling, 24-bit, delta-sigma (ΔΣ) analog-to-digital converter (ADC) with a low-drift internal reference voltage from Texas Instruments. The dynamic range, size, feature set, and power consumption are optimized for cost-sensitive applications requiring simultaneous sampling. An integrated negative charge pump allows absolute input voltages as low as -1.3V, enabling input signal measurements varying around the ground with a single-ended power supply. The ADS131M02 features a programmable gain amplifier (PGA) with gains up to 128. An integrated input pre-charge buffer enabled at gains greater than 4 ensures high input impedance at high PGA gain settings. The ADC receives its reference voltage from an integrated 1.2V reference, allowing differential input voltages as large as the reference. Each channel on the ADS131M02 contains a digital

decimation filter that demodulates the output of the ΔΣ modulators. The filter enables data rates as high as 32kSPS per channel in high-resolution mode. The relative phase of the samples can be configured between channels, thus allowing an accurate compensation for the sensor phase response. Offset and gain calibration registers can be programmed to automatically adjust output samples for measured offset and gain errors. The ADC 15 Click communicates with MCU through a standard SPI interface to read the conversion data and configure and control the ADS131M02, supporting the most common SPI mode - SPI Mode 1. To normally run the ADS131M02, an LVCMOS clock must be continuously provided at the CLKIN pin, which is achieved with the LTC6903 programmable oscillator activated via the CS2 pin routed to the PWM pin on the mikroBUS™ socket. The frequency of the clock can be scaled in conjunction

with the power mode to provide a trade-off between power consumption and dynamic range. Selection of the bits in the CLOCK register allows the device to be configured in one of three power modes: high-resolution (HR) mode, low-power (LP) mode, and very low-power (VLP) mode. In addition, this Click board™ also uses features such as data-ready/interrupt routed to the INT pin on the mikroBUS™ socket, which serves as a flag to the host to indicate that new conversion data are available and Reset routed to the RST pin that allows for a hardware device reset. This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used as a reference for further development.

ADC 15 Click top side image
ADC 15 Click lateral side image
ADC 15 Click bottom side image

Features overview

Development board

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.

PIC18F57Q43 Curiosity Nano double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

48

RAM (Bytes)

8196

You complete me!

Accessories

Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.

Curiosity Nano Base for Click boards accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Reset
PA7
RST
SPI Chip Select
PD4
CS
SPI Clock
PC6
SCK
SPI Data OUT
PC5
MISO
SPI Data IN
PC4
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
LTC6903 Enable
PB0
PWM
Data-Ready / Interrupt
PA6
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

ADC 15 Click Schematic schematic

Step by step

Project assembly

Curiosity Nano Base for Click boards front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F57Q43 as your development board.

Curiosity Nano Base for Click boards front image hardware assembly
Charger 27 Click front image hardware assembly
PIC18F47Q10 Curiosity Nano front image hardware assembly
Prog-cut hardware assembly
Charger 27 Click complete accessories setup image hardware assembly
Curiosity Nano with PICXXX 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 image step 5 hardware assembly
Necto image step 6 hardware assembly
PIC18F57Q43 Curiosity 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 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.

DEBUG_Application_Output

Software Support

Library Description

This library contains API for ADC 15 Click driver.

Key functions:

  • adc15_read_voltage Get voltage value.

  • adc15_set_gain Set gain for channel.

  • adc15_set_word_len Set word len.

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 main.c
 * @brief ADC15 Click example
 *
 * # Description
 * This example showcases ability of the click board to 
 * read adc data from 2 different channels. It's also configuratable
 * to read data in different output rate, resolutions( word/data len ),
 * and gain.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization of communication modules (SPI, UART) and additional
 * pins for control of the device. Sets default configuration, that 
 * sets gain of 1 for both channels(+/-1.2V range) and word/data length
 * of 24bit. In the end reads device ID.
 *
 * ## Application Task
 * Waits for data ready signal and reads voltage value of both channels,
 * and logs read status and channel voltage level.
 *
 * @author Luka Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "adc15.h"
#include "math.h"

static adc15_t adc15;
static log_t logger;

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    adc15_cfg_t adc15_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.
    adc15_cfg_setup( &adc15_cfg );
    ADC15_MAP_MIKROBUS( adc15_cfg, MIKROBUS_1 );
    err_t init_flag  = adc15_init( &adc15, &adc15_cfg );
    if ( SPI_MASTER_ERROR == init_flag )
    {
        log_error( &logger, " Communication Init. " );
        log_info( &logger, " Please, run program again... " );
        for ( ; ; );
    } 

    if ( adc15_default_cfg ( &adc15 ) )
    {
        log_error( &logger, " Default configuration. " );
        for( ; ; );
    }
    
    uint16_t reg_val;
    adc15_reg_read( &adc15, ADC15_REG_ID, &reg_val );
    log_printf( &logger, " > ID: 0x%.4X\r\n", reg_val );
    
    log_info( &logger, " Application Task " );
    Delay_ms ( 1000 );
}

void application_task ( void )
{
    while ( adc15_data_ready( &adc15 ) );
    float channel1 = 0;
    float channel2 = 0;
    uint16_t status = 0;
    if ( !adc15_read_voltage( &adc15, &status, &channel1, &channel2 ) )
    {
        log_printf( &logger, " > Status: 0x%.4X\r\n", status );
        log_printf( &logger, " > V ch1: %.3f\r\n", channel1 );
        log_printf( &logger, " > V ch2: %.3f\r\n", channel2 );    
        log_printf( &logger, "************************\r\n" );
        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;
}

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

Additional Support

Resources

Love this project?

'Buy This Kit' button takes you directly to the shopping cart where you can easily add or remove products.