Experience the future of smart agriculture with MIC1557 and PIC32MZ1024EFH064

Unearth growth secrets through capacitive moisture mastery!

Published Aug 24, 2023

Click board™

Hydro Probe Click

Dev. board

PIC32MZ clicker

Compiler

NECTO Studio

MCU

PIC32MZ1024EFH064

From sustainable gardening to precision farming, our capacitive soil moisture sensing solution offers unparalleled accuracy, helping you make informed decisions by monitoring volumetric water content in the soil

Hardware Overview

How does it work?

Hydro Probe Click uses the capacitive soil moisture sensor based on capacitive changes that are used to detect the volumetric water content of the soil. It based its operation on capacitive measurement, which has a great advantage over resistive measurement. Compared with resistive soil moisture sensors, capacitive sensors do not require direct exposure to the metal electrodes, which can significantly reduce the erosion of the electrodes. This Click board™ can only qualitatively test the humidity of the soil and can’t measure quantitatively. When the humidity of the soil rises, the output value decreases; conversely, when the humidity decreases, the output value becomes higher. It operates with a flexible power

supply voltage range, making it suitable for 3.3V and 5V MCUs. Hydro Probe Click functions as a capacitive soil moisture sensor using two main components, CMOS RC oscillator MIC1557 and 12-bit A/D converter MCP3221 with I2C serial interface. The oscillator frequency is set to 600kHz. From the oscillator, a signal goes to the soil moisture probe through a 10k resistor; these two elements act as a low-pass filter for the oscillator signal. The output analog signal from the capacitive probe goes through a diode to the MCP3221, A/D converter with 12-bit resolution, which converts that data and sends it to MCU. Communication to the MCP3221 is performed using a 2-wire I2C serial interface with available standard (100 kHz) or fast

(400 kHz) modes. To ensure you received the correct data, the Hydro Probe Click must be calibrated. The final output value is affected by probe insertion depth and how tight the soil packed around it is. It‘s recommended that the probe should not be placed on the depth which crosses the limit line on the Click board. 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.

Features overview

Development board

PIC32MZ Clicker is a compact starter development board that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit PIC32MZ microcontroller with FPU from Microchip, a USB connector, LED indicators, buttons, a mikroProg connector, and a header for interfacing with external electronics. Thanks to its compact design with clear and easy-recognizable silkscreen markings, it provides a fluid and immersive working experience, allowing access anywhere and under

any circumstances. Each part of the PIC32MZ Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the PIC32MZ Clicker programming method, using USB HID mikroBootloader, or through an external mikroProg connector for PIC, dsPIC, or PIC32 programmer, the Clicker board also includes a clean and regulated power supply module for the development kit. The USB Micro-B connection can provide up to 500mA of current, which is more than enough to operate all onboard

and additional modules. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several buttons and LED indicators. PIC32MZ Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping 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

Architecture

PIC32

MCU Memory (KB)

1024

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

524288

You complete me!

Accessories

mikroBUS Shuttle Bundle is designed to significantly expand development systems by providing additional mikroBUS™ slots for integrating multiple Click boards™. It is based on the Shuttle click, which enables connection of mikroBUS Shuttle add-on boards via ICD BOX headers. The key feature of this board is its near-unlimited stacking capacity, allowing numerous mikroBUS™ connections while maintaining mirrored pin functionality across all ICD BOX headers. However, caution is advised with signal line length and power distribution, especially when using high-frequency communication protocols or power-hungry Click boards™. I2C and 1-Wire protocols are especially suitable due to built-in collision avoidance and address configuration options. This makes the Shuttle click an ideal solution for complex prototyping setups that require simultaneous use of various Click boards™, including sensors, communication modules, and control interfaces.

Used MCU Pins

mikroBUS™ mapper

RST

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

PWM

INT

I2C Clock

RD10

SCL

I2C Data

RD9

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

PIC32MZ clicker front image hardware assembly

Start by selecting your development board and Click board™. Begin with the PIC32MZ clicker as your development board.

GNSS2 Click front image hardware assembly

GNSS2 Click complete accessories setup image hardware assembly

Board mapper by product7 hardware assembly

Flip&Click PIC32MZ MCU step hardware assembly

Necto No Display image step 8 hardware assembly

Debug Image Necto Step hardware assembly

Software Support

Library Description

This library contains API for Hydro Probe Click driver.

Key functions:

hydroprobe_avg_val - Get average value function
hydroprobe_min_val - Get minimum value function
hydroprobe_rel_env_hum - Get Relative humidity of the environment 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 
 * \brief HydroProbe Click example
 * 
 * # Description
 * This demo application measures moisture.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initalizes I2C driver, prerforms calibration and makes an initial log.
 * 
 * ## Application Task  
 * This example shows the capabilities of the Hydro Probe Click by measuring 
 * environment moisture content and displaying it in percent via USB UART.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "hydroprobe.h"

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

static hydroprobe_t hydroprobe;
static log_t logger;

static uint8_t humy_val = 0;
static uint16_t dry_val = 0;
static uint16_t wet_val = 0;

// ------------------------------------------------------- ADDITIONAL FUNCTIONS

void hydroprobe_calib ( )
{
    uint8_t cnt;

    log_printf( &logger, " Keep the Probe dry \r\n" );
    dry_val = hydroprobe_max_val( &hydroprobe );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    log_printf( &logger, " Submerge the Probe in liquid \r\n" );
    for ( cnt = 5; cnt > 0; cnt-- )
    {
        log_printf( &logger, " %d \r\n ", ( uint16_t ) cnt );
        Delay_ms ( 1000 );
    }
    log_printf( &logger, " Keep the Probe submerged \r\n" );
    Delay_ms ( 100 );
    wet_val = hydroprobe_min_val( &hydroprobe );
    log_printf( &logger, "--------------------\r\n" );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
}

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    hydroprobe_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.

    hydroprobe_cfg_setup( &cfg );
    HYDROPROBE_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    hydroprobe_init( &hydroprobe, &cfg );
    
    Delay_ms ( 100 );

    log_printf( &logger, "---------------------\r\n" );
    log_printf( &logger, "  Hydro Probe Click  \r\n" );
    log_printf( &logger, "---------------------\r\n" );
    hydroprobe_calib( );
    log_printf( &logger, "     Calibrated      \r\n" );
    log_printf( &logger, "---------------------\r\n" );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
}

void application_task ( void )
{
    humy_val = hydroprobe_rel_env_hum( &hydroprobe, dry_val, wet_val );
    log_printf( &logger, "Environment moisture content: %d %% \r\n ", ( uint16_t ) humy_val );
    log_printf( &logger, "------------------------------\r\n" );
    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