Digitizes the input voltage with MAX22530 and PIC18F57Q43 and transmits the data across the isolation barrier
Step into the future of data conversion
Published Feb 13, 2024
Click board™
ISO ADC 5 Click
Dev. board
Curiosity Nano with PIC18F57Q43
Compiler
NECTO Studio
MCU
PIC18F57Q43
Harness the power of isolation for accurate signal conversion with our A/D converter
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Hardware Overview
How does it work?
ISO ADC 5 Click is based on the MAX22530, a 12-bit, 4-channel ADC with a 5kVRMS isolated SPI interface from Analog Devices. The ADC and all field-side circuits are powered by an integrated, isolated DC-DC converter that can verify field-side functionality even when there is no input signal or other field-side supply. It continually digitizes the input voltage on the field side of an isolation barrier and transmits the data across the isolation barrier to the logic side of the devices, where the magnitude of the input voltage is compared to programmable thresholds. The MAX22530 ADC employs a 12-bit SAR architecture with a nominal sampling rate of 20ksps per channel and has an
input voltage of up to 1.8V. Placed voltage dividers make the proper ADC input voltage on the analog input channels, which, based on the input in the range from 0 to 48V, gives the required input to the ADC in its range from 0 to 1.8V. After Power-Up, the ADC runs continually at the nominal sampling rate. The MAX22530 also features a precision internal voltage reference of 1.8V with a maximum error of ±2% over the entire operating temperature range. The MAX22530 communicates with MCU using the standard SPI serial interface with a maximum frequency 10MHz. Besides, it continuously monitors multiple possible fault conditions such as ADC functionality error, SPI framing
error, CRC errors from SPI communications, and internal isolated data stream loss. This hardware alert feature is provided through the interrupt pin, routed on the CS pin of the mikroBUS™ socket, which asserts low when an enabled fault is detected. 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. 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.
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.
Microcontroller Overview
MCU Card / MCU
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.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F57Q43 as your development board.
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 ISO ADC 5 Click driver.
Key functions:
isoadc5_cfg_setup- Config Object Initialization function.isoadc5_init- Initialization 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 ISOADC5 Click example
*
* # Description
* This example demonstrates the use of ISO ADC 5 click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and makes an initial log.
*
* ## Application Task
* Reads the voltage from all input channels and displays the values of
* each channel on the USB UART approximately every second.
*
* @note
* The voltage input range is from 0 to 48V.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "isoadc5.h"
static isoadc5_t isoadc5;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
isoadc5_cfg_t isoadc5_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 );
Delay_ms ( 100 );
log_info( &logger, " Application Init " );
// Click initialization.
isoadc5_cfg_setup( &isoadc5_cfg );
ISOADC5_MAP_MIKROBUS( isoadc5_cfg, MIKROBUS_1 );
err_t init_flag = isoadc5_init( &isoadc5, &isoadc5_cfg );
if ( SPI_MASTER_ERROR == init_flag )
{
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float v_ain1 = 0, v_ain2 = 0, v_ain3 = 0, v_ain4 = 0;
err_t error_flag = isoadc5_read_voltage( &isoadc5, ISOADC5_ADC_FILTERED, ISOADC5_ADC_CHANNEL_1, &v_ain1 );
error_flag |= isoadc5_read_voltage( &isoadc5, ISOADC5_ADC_FILTERED, ISOADC5_ADC_CHANNEL_2, &v_ain2 );
error_flag |= isoadc5_read_voltage( &isoadc5, ISOADC5_ADC_FILTERED, ISOADC5_ADC_CHANNEL_3, &v_ain3 );
error_flag |= isoadc5_read_voltage( &isoadc5, ISOADC5_ADC_FILTERED, ISOADC5_ADC_CHANNEL_4, &v_ain4 );
if ( ISOADC5_OK == error_flag )
{
log_printf( &logger, " AIN 1 voltage: %.3f V\r\n", v_ain1 );
log_printf( &logger, " AIN 2 voltage: %.3f V\r\n", v_ain2 );
log_printf( &logger, " AIN 3 voltage: %.3f V\r\n", v_ain3 );
log_printf( &logger, " AIN 4 voltage: %.3f V\r\n\r\n", v_ain4 );
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
