Provide accurate detection of lightning activity with AS3935 and PIC18F47K42TQFP

Experience the power of ThunderSense!

Thunder Click with Curiosity Nano with PIC18F47K42

Published Feb 13, 2024

Click board™

Thunder Click

Dev. board

Curiosity Nano with PIC18F47K42

Compiler

NECTO Studio

MCU

PIC18F47K42TQFP

Detect the presence and proximity of potentially dangerous lightning activity in the surrounding area

Hardware Overview

How does it work?

Thunder Click is based on the AS3935, a programmable fully integrated lightning sensor from ams AG that detects the approach of potentially hazardous lightning activity with a sensitive coil antenna, and the MA5532 from Coilcraft. The embedded lightning algorithm checks the incoming signal pattern to reject the potential manufactured disturbers, provides information on the noise level, and informs the host MCU in case of high noise conditions. If the signal is classified as a manufactured disturber, the event is rejected, and the sensor automatically returns to listening mode. Still, if the event is classified as a lightning strike, the statistical distance estimation block evaluates the distance to the head of the storm. The MA5532 external antenna is directly connected to the AS3935's Analog Front-end (AFE), which amplifies

and demodulates the received signal. The watchdog continuously monitors the output of the AFE and alerts the integrated lightning algorithm block in the event of an incoming signal. The embedded hardwired distance estimation algorithm of the AS3935 issues an interrupt on the IRQ pin, routed to the INT pin of the mikroBUS™ socket, every time lightning is detected. The estimated distance, displayed in the distance estimation register, does not represent the distance to the single lightning but the estimated distance to the storm's leading edge. Besides detecting potentially hazardous lightning activity, this Click board™ also provides information on the estimated distance to the storm's center on the noise level. The AS3935 can detect lightning up to 40km away with an accuracy of 1km to the storm front with a sensitive

antenna tuned to pick up lightning events in the 500kHz band. The AS3935 lightning sensor communicates with MCU using the SPI serial interface with a maximum SPI frequency of 2MHz. Note that the clock operation frequency of the SPI should not be identical to the resonance frequency of the antenna (500kHz) to minimize the onboard noise. 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.

Features overview

Development board

PIC18F47K42 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate the PIC18F47K42 microcontroller (MCU). Central to its design is the inclusion of the powerful PIC18F47K42 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 2.3V to 5.1V (limited by USB input voltage), with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.

PIC18F47K42 Curiosity Nano double side image

Microcontroller Overview

MCU Card / MCU

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

8192

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

RST

SPI Chip Select

PD4

SPI Clock

PC6

SCK

SPI Data OUT

PC5

MISO

SPI Data IN

PC4

MOSI

Power Supply

3.3V

Ground

GND

PWM

Interrupt

PA6

INT

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ 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 PIC18F47K42 as your development board.

Barometer 13 Click front image hardware assembly

PIC18F47K42 Curiosity Nano front image hardware assembly

Curiosity Nano with PIC18F47XXX MB 1 - upright/background hardware assembly

PIC18F57Q43 Curiosity MCU Step hardware assembly

Necto No Display image step 8 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 Thunder Click driver.

Key functions:

thunder_check_interr - This function checks and returns the interrupt value
thunder_get_storm_info - This function gets energy of the single lightning and distance estimation for the head of the storm
thunder_read_reg - This function reads the desired number of bytes from the registers

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 
 * \brief Thunder Click example
 * 
 * # Description
 * This application detects the presence and proximity of potentially 
 * lightning activity and provides estimated distance to the center of the storm. 
 * It can also provide information on the noise level.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes SPI driver and performs the reset command and RCO calibrate command.
 * Also configures the device for working properly.
 * 
 * ## Application Task  
 * Always checks is interrupt event happend (Listening mode) and 
 * after that gets the informations about storm. Results logs on UART.
 * 
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "thunder.h"

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

static thunder_t thunder;
static log_t logger;

uint8_t storm_mode;
uint32_t storm_energy;
uint8_t storm_distance;


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

void application_init ( void )
{
    log_cfg_t log_cfg;
    thunder_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.

    thunder_cfg_setup( &cfg );
    THUNDER_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    thunder_init( &thunder, &cfg );

    thunder_default_cfg( &thunder );
    Delay_ms( 300 );
}

void application_task ( void )
{
    storm_mode = thunder_check_interr( &thunder );

    if ( storm_mode == THUNDER_NOISE_LEVEL_INTERR )
    {
        log_printf( &logger, "Noise level too high\r\n" );
    }
    else if ( storm_mode == THUNDER_DISTURBER_INTERR )
    {
        log_printf( &logger, "Disturber detected\r\n" );
    }
    else if ( storm_mode ==  THUNDER_LIGHTNING_INTERR )
    {
        thunder_get_storm_info( &thunder, &storm_energy, &storm_distance );

        log_printf( &logger, "Energy of the single lightning : %ld\r\n", storm_energy );
        log_printf( &logger, "Distance estimation :  %d km\r\n", storm_distance );
    }

    Delay_ms( 1000 );
}

void main ( void )
{
    application_init( );

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


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