Provide accurate detection of lightning activity with AS3935 and PIC32MX764F128L

Experience the power of ThunderSense!

Published Jun 19, 2023

Click board™

Thunder Click

Dev Board

UNI-DS v8

Compiler

NECTO Studio

MCU

PIC32MX764F128L

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

UNI-DS v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different STM32, Kinetis, TIVA, CEC, MSP, PIC, dsPIC, PIC32, and AVR MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, UNI-DS v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the UNI-DS v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART, USB

HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. UNI-DS v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

Microcontroller Overview

MCU Card / MCU

Type

8th Generation

Architecture

PIC32

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

32768

Used MCU Pins

mikroBUS™ mapper

RST

SPI Chip Select

PD7

SPI Clock

PD10

SCK

SPI Data OUT

PC4

MISO

SPI Data IN

PD0

MOSI

Power Supply

3.3V

Ground

GND

PWM

Interrupt

PE8

INT

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI-DS v8 as your development board.

NECTO Output Selection Step Image hardware assembly

In the advanced settings, pay special attention to the Redirect standard output field. By default, it is set to Application output as the method of displaying final results. To show results via a UART terminal, select the “UART” option in that field and click the “SAVE” button. You will be returned to the Compiler field, and now you can move on to the next step by pressing the “NEXT” button.

GNSS2 Click front image hardware assembly

SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly

v8 SiBRAIN Access MB 1 - upright/background hardware assembly

NECTO Compiler Selection Step Image hardware assembly

Track your results in real time

Application Output

This Click board can be interfaced and monitored in two ways:

Application Output - Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.

UART Terminal - Monitor data via the UART Terminal using a USB to UART converter. For detailed instructions, check out this tutorial.

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