Convert real-world physical quantities into digital data with AD7124-8 and PIC32MZ2048EFM100
Eight-channel isolated sigma-delta ADC with PGA
Published Feb 01, 2024
Click board™
ISO ADC 6 Click
Dev.Board
Curiosity PIC32 MZ EF
Compiler
NECTO Studio
MCU
PIC32MZ2048EFM100
High-precision analog-to-digital conversion with isolation capabilities suitable for various industrial and measurement applications
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Hardware Overview
How does it work?
ISO ADC 6 Click is based on the AD7124-8, an 8-channel, low noise, low power, 24-bit, sigma-delta ADC, and the ADuM341E, a 5kVrms quad digital isolator, both from Analog Devices. The ADC incorporates a sigma-delta modulator, buffer, reference, gain stage, and on-chip digital filtering. It is intended to measure wide dynamic ranges, weigh scales, temperature measurement applications, and low-frequency signals. The ADC allows up to 16 configurations or channels consisting of analog inputs, reference inputs, or power supplies. All ADC channels are available over the A0-15 header, with a common GND, power supply, and a bridge power switch (PSW). You can add an external reference over the REF+ and REF-
pins. The internal reference has its output available over the REFOUT pin. The synchronization input is also available over the SNC pin. It allows synchronization of the digital filters and analog modulators when using several AD7124-8 devices. For this purpose, the internal clock is available over the CLK pin. Alternatively, the internal clock can be turned off, and this pin can provide an external clock, allowing simultaneous conversions. The isolator isolates the ADC communication lines to the host MCU. It features low propagation delay, low dynamic power consumption, 100Mbps maximum guaranteed data rate, and more. The isolator is based on CMOS, a monolithic air core transformer technology, and iCoupler technology.
ISO ADC 6 Click uses a standard 4-wire SPI serial interface of the ADC to communicate with the host MCU over the isolator barrier. The isolator uses a high-frequency carrier to transmit data across the isolation barrier using iCoupler chip scale transformer coils separated by layers of polyimide isolation. The ADC can work in three power modes, which allows sampling in a range of 1.17sps up to 19200sps. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.
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.
Microcontroller Overview
MCU Card / MCU
Architecture
PIC32
MCU Memory (KB)
2048
Silicon Vendor
Microchip
Pin count
100
RAM (Bytes)
524288
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Curiosity PIC32 MZ EF as your development board.
Track your results in real time
Application Output
After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.
After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.
Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.
Software Support
Library Description
This library contains API for ISO ADC 6 Click driver.
Key functions:
isoadc6_get_voltage- ISO ADC 6 get voltage level functionisoadc6_get_adc_data- ISO ADC 6 get ADC data functionisoadc6_set_adc_control- ISO ADC 6 set ADC control function
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 ISO ADC 6 Click example
*
* # Description
* This example demonstrates the use of the ISO ADC 6 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 which enables channel 0,
* puts A0 on positive analog input and A1 on negative analog input,
* enables internal reference voltage (approximately 2.65V (AVDD = 3.3V)),
* and also enables bipolar operation mode and puts device on full power mode.
*
* ## Application Task
* The demo application reads the voltage levels from analog input (A0-A1) and displays the results.
* Results are being sent to the UART Terminal, where you can track their changes.
*
* @author Mikroe Team
*
*/
#include "board.h"
#include "log.h"
#include "isoadc6.h"
static isoadc6_t isoadc6;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
isoadc6_cfg_t isoadc6_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.
isoadc6_cfg_setup( &isoadc6_cfg );
ISOADC6_MAP_MIKROBUS( isoadc6_cfg, MIKROBUS_1 );
if ( SPI_MASTER_ERROR == isoadc6_init( &isoadc6, &isoadc6_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( ISOADC6_ERROR == isoadc6_default_cfg ( &isoadc6 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float voltage = 0;
if ( ISOADC6_OK == isoadc6_get_voltage( &isoadc6, &voltage ) )
{
log_printf( &logger, " Voltage: %.3f [V]\r\n", voltage );
Delay_ms( 1000 );
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
