Beginner
10 min

Experience the power of efficient signal conversion with ADS8665 and PIC32MZ2048EFM100

From analog to awesome

ADC 22 Click with Curiosity PIC32 MZ EF

Published Nov 13, 2023

Click board™

ADC 22 Click

Dev. board

Curiosity PIC32 MZ EF

Compiler

NECTO Studio

MCU

PIC32MZ2048EFM100

Our analog-to-digital converter seamlessly transforms complex analog signals into precise digital data, ensuring unparalleled accuracy in every conversion.

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Hardware Overview

How does it work?

ADC 22 Click is based on the ADS8665, a 12-bit high-speed single-supply SAR ADC data acquisition system with programmable bipolar input ranges from Texas Instruments. This ADC operates on a single 5V supply used from the mikroBUS™ power rail and supports true bipolar input ranges of ±12.288V, ±6.144V, ±10.24V, ±5.12V, and ±2.56V, as well as unipolar input ranges of 0 to 12.288V, or 10.24V, 6.144V, and 5.12V. The gain and offset errors are accurately trimmed within specified values to ensure a high DC precision for each input range. The input range selection is made by software. The ADC features an overvoltage protection circuit of up to ±20V and an on-chip 4.096V reference with extremely low-temperature drift. In addition, ADC 22 Click is equipped with an external voltage reference REF header, which allows you to apply voltages to

ADS8665 ADC from 4.046 up to 4.146V. You can separate the grounds for external voltage reference usage by desoldering the NET TIE R2 resistor. The ADC 22 Click features alarm functions that consist of an input alarm and an AVDD supply alarm. The alarm function should be enabled over the software, thus enabling both alarm functions by default. You can later separately disable one of them. Another neat feature of this Click board™ is the RVS multi-function output pin, which, regarding the CS pin status, can reflect the status of the internal ADCST signal or the status of the RVS depending on the output protocol selection. The device allows the output clock on the RVS pin to be synchronous to either the external clock provided on the SCLK pin or to the device's internal clock. In all SRC modes of operation, the RVS pin provides the output clock, synchronous to

the device data output. The RVS pin can be monitored for timing benefits. ADC 22 Click uses a standard 4-Wire SPI serial interface to communicate with the host MCU supporting high serial clock frequency. It also supports an enhanced SPI interface (multiSPI) that maximizes the sampling rate even with lower-speed host controllers. The alarm interrupt is available on the INT pin, and you can reset the device over the RST pin. The RVS pin is a multi-function pin for the serial interface. 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.

ADC 22 Click hardware overview image

Features overview

Development board

Curiosity PIC32 MZ EF development board is a fully integrated 32-bit development platform featuring the high-performance PIC32MZ EF Series (PIC32MZ2048EFM) that has a 2MB Flash, 512KB RAM, integrated FPU, Crypto accelerator, and excellent connectivity options. It includes an integrated programmer and debugger, requiring no additional hardware. Users can expand

functionality through MIKROE mikroBUS™ Click™ adapter boards, add Ethernet connectivity with the Microchip PHY daughter board, add WiFi connectivity capability using the Microchip expansions boards, and add audio input and output capability with Microchip audio daughter boards. These boards are fully integrated into PIC32’s powerful software framework, MPLAB Harmony,

which provides a flexible and modular interface to application development a rich set of inter-operable software stacks (TCP-IP, USB), and easy-to-use features. The Curiosity PIC32 MZ EF development board offers expansion capabilities making it an excellent choice for a rapid prototyping board in Connectivity, IOT, and general-purpose applications.

Curiosity PIC32MZ EF double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC32

MCU Memory (KB)

2048

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

Multifunction Output
RPB4
AN
Reset
RA9
RST
SPI Chip Select
RPD4
CS
SPI Clock
RPD1
SCK
SPI Data OUT
RPD14
MISO
SPI Data IN
RPD3
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Alarm Interrupt
RF13
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

ADC 22 Click Schematic schematic

Step by step

Project assembly

Curiosity PIC32MZ EF front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity PIC32 MZ EF as your development board.

Curiosity PIC32MZ EF front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
Curiosity PIC32 MZ EF MB 1 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
Curiosity PIC32 MZ EF 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 ADC 22 Click driver.

Key functions:

  • adc22_get_voltage - ADC 22 get voltage level function.

  • adc22_get_adc_raw_data - ADC 22 get ADC raw data function.

  • adc22_set_range - ADC 22 set range function.

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 ADC 22 Click example
 *
 * # Description
 * This example demonstrates the use of the ADC 22 Click board™ 
 * by reading and writing data by using SPI serial interface and reading results of AD conversion.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization of SPI module and log UART.
 * After driver initialization, the app executes a default configuration.
 *
 * ## Application Task
 * The demo application reads the voltage levels from analog input and displays the results.
 * By default, the operating input range sets from 0V to 12.288V [3×Vref;Vref=4.096V].
 * Results are being sent to the UART Terminal, where you can track their changes.
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "adc22.h"

static adc22_t adc22;
static log_t logger;

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    adc22_cfg_t adc22_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.
    adc22_cfg_setup( &adc22_cfg );
    ADC22_MAP_MIKROBUS( adc22_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == adc22_init( &adc22, &adc22_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    Delay_ms( 100 );
    
    if ( ADC22_ERROR == adc22_default_cfg ( &adc22 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    Delay_ms( 100 );
    
    log_info( &logger, " Application Task " );
    log_printf( &logger, " ----------------\r\n" );
    Delay_ms( 100 );
}

void application_task ( void )
{   
    static float voltage = 0.0;
    if ( ADC22_OK == adc22_get_voltage ( &adc22, &voltage ) )
    {
        log_printf( &logger, " Voltage : %.2f V\r\n", voltage );
        log_printf( &logger, " ----------------\r\n" );
        Delay_ms( 1000 );
    }
}

void main ( void )
{
    application_init( );

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

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

Additional Support

Resources

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