Beginner
10 min

Step into the world of digital data with MCP3551 and PIC32MZ1024EFH064

Where analog meets digital

ADC 2 Click with PIC32MZ clicker

Published May 31, 2023

Click board™

ADC 2 Click

Dev Board

PIC32MZ clicker

Compiler

NECTO Studio

MCU

PIC32MZ1024EFH064

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Hardware Overview

How does it work?

ADC 2 Click is based on the MCP3551, a 22-bit precise single-channel ΔΣ analog-to-digital converter from Microchip. The MCP3551 includes fully differential analog input on a VIN terminal, a third-order delta-sigma modulator, a fourth-order modified SINC decimation filter (allows superior averaging performance), an on-chip, low-noise internal oscillator, a power supply monitoring circuit, and an SPI digital interface. It can be easily used to measure low-frequency, low-level signals such as those found in pressure transducers, temperature, strain gauges, industrial control, or process control applications. This Click board™ communicates with MCU through a 3-Wire SPI interface (read-only) with a maximum frequency of 5MHz. The interface offers two conversion modes: A single Conversion mode for multiplexed

applications and a Continuous Conversion mode for multiple conversions in series, where every conversion is independent of each other (all internal registers are flushed between conversions). When the MCP3551 is not converting, it automatically goes into Shutdown mode, characterized by low power consumption. The MCP3551 provides single-cycle conversions with no digital filter settling time. Every conversion includes an internal offset and gain auto-calibration to reduce device error, which is transparent to the user and done in real-time during the conversion, allowing multiplexed applications. Like any ADC, the MCP3551 uses a reference voltage as the differential voltage range. The reference voltage level selection is performed by positioning the SMD jumper labeled as VREF

SEL to an appropriate position choosing between 3.3V or 5V provided by the mikroBUS™ power rails or 4.096V provided by MCP1541. These voltages may be used as the reference input that results in accuracy and stability. Besides, the ADC 2 Click supports an external power supply for the MCP3551, which can be connected to the input terminal labeled as VCC OUT and should be within the range of 2.7V to 5.5V. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the PWR SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. However, the 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.

ADC 2 Click hardware overview image

Features overview

Development board

PIC32MZ Clicker is a compact starter development board that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit PIC32MZ microcontroller with FPU from Microchip, a USB connector, LED indicators, buttons, a mikroProg connector, and a header for interfacing with external electronics. Thanks to its compact design with clear and easy-recognizable silkscreen markings, it provides a fluid and immersive working experience, allowing access anywhere and under

any circumstances. Each part of the PIC32MZ Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the PIC32MZ Clicker programming method, using USB HID mikroBootloader, or through an external mikroProg connector for PIC, dsPIC, or PIC32 programmer, the Clicker board also includes a clean and regulated power supply module for the development kit. The USB Micro-B connection can provide up to 500mA of current, which is more than enough to operate all onboard

and additional modules. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several buttons and LED indicators. PIC32MZ Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

PIC32MZ clicker double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC32

MCU Memory (KB)

1024

Silicon Vendor

Microchip

Pin count

64

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
SPI Chip Select
RG9
CS
SPI Clock
RG6
SCK
SPI Data OUT
RG7
MISO
NC
NC
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

Schematic

ADC 2 Click Schematic schematic

Step by step

Project assembly

PIC32MZ clicker front image hardware assembly

Start by selecting your development board and Click board™. Begin with the PIC32MZ clicker as your development board.

PIC32MZ clicker front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
Micro B Connector Clicker Access - 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
Flip&Click PIC32MZ 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 2 Click driver.

Key functions:

  • adc2_adc_Value_Read - Function is used to read specific data from ADC convertor.

  • adc2_check_Over_Low - Function is used to check overflow low state.

  • adc2_check_Over_High - Function is used to check overflow high state.

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 Adc2 Click example
 * 
 * # Description
 * This application enables usage of the 22bit ADC.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initalizes SPI driver and makes an initial log.
 * 
 * ## Application Task  
 * This is an example that shows the capabilities of the ADC 2 click
 * 
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "adc2.h"

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

static adc2_t adc2;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    adc2_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.

    adc2_cfg_setup( &cfg );
    ADC2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    adc2_init( &adc2, &cfg );

    Delay_ms( 100 );
    
    adc2_set_vref( &adc2, ADC2_VCC_3v3 );

    log_printf( &logger, "------------------\r\n" );
    log_printf( &logger, "    ADC 2 Click   \r\n" );
    log_printf( &logger, "------------------\r\n" );
}

void application_task ( void )
{
    float adc_val;

    //  Task implementation.

    adc_val = adc2_read_adc_data( &adc2 );

    log_printf( &logger, "Value : %.2f mV\r\n", adc_val );
    
    if ( adc2.ovf_h )
        log_printf( &logger, "HIGH OVERFLOW DETECTED\r\n" );
    else if ( adc2.ovf_l )
        log_printf( &logger, "LOW OVERFLOW DETECTED\r\n" );
    
    log_printf( &logger, "------------------\r\n" );
    Delay_ms( 500 );
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources

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