Our solution is designed to provide real-time, visual confirmation of liquid flow within clear tubes, ensuring precision and accuracy in fluid management.
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Hardware Overview
How does it work?
Water Detect 2 Click is based on the OPB350L250, a tube liquid sensor from TT Electronics. It consists of an LED and a phototransistor, where the phototransistor reads the light of an LED that passes through a clear tube. Depending on the liquid that passes through, you can distinguish light from dark liquid, no liquid presence, bubbles in the liquid that passes through the tube, or even no tube presence at all. You will have to identify the typical current values for each situation, where the ratio between the different states allows the acknowledgment of different conditions. In addition, the sensor itself comes in an opaque
plastic housing that enhances ambient light rejection. The housing „clicks“ around the tube, allowing a secure and tight connection. Water Detect 2 Click uses the MCP6022, a rail-to-rail input/output operational amplifier from Microchip, to amplify the output of the liquid sensor. For a visual presentation of the fluid sensor status, this Click board™ has an RGB LED that uses all three colors to indicate water detection, no water detection, and the LED ON. The onboard VREF potentiometer is used for the calibration of the liquid sensor. This way, you can set the threshold for what you want to detect. Water Detect
2 Click uses an interrupt DET pin (liquid detection) to communicate with the host MCU. In addition, you can turn the LED ON/OFF over the ON pin of the mikroBUS™ socket. 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
Nucleo-144 with STM32F413ZH MCU board offers an accessible and adaptable avenue for users to explore new ideas and construct prototypes. It allows users to tailor their experience by selecting from a range of performance and power consumption features offered by the STM32 microcontroller. With compatible boards, the
internal or external SMPS dramatically decreases power usage in Run mode. Including the ST Zio connector, expanding ARDUINO Uno V3 connectivity, and ST morpho headers facilitate easy expansion of the Nucleo open development platform. The integrated ST-LINK debugger/programmer enhances convenience by
eliminating the need for a separate probe. Moreover, the board is accompanied by comprehensive free software libraries and examples within the STM32Cube MCU Package, further enhancing its utility and value.
Microcontroller Overview
MCU Card / MCU

Architecture
ARM Cortex-M4
MCU Memory (KB)
1536
Silicon Vendor
STMicroelectronics
Pin count
144
RAM (Bytes)
327680
You complete me!
Accessories
Click Shield for Nucleo-144 comes equipped with four mikroBUS™ sockets, with one in the form of a Shuttle connector, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-144 board with no effort. This way, MIKROE allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. Featuring an ARM Cortex-M microcontroller, 144 pins, and Arduino™ compatibility, the STM32 Nucleo-144 board offers limitless possibilities for prototyping and creating diverse applications. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-144 board out of the box, with an additional USB cable connected to the USB mini port on the board. Simplify your project development with the integrated ST-Link debugger and unleash creativity using the extensive I/O options and expansion capabilities. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-144 board with our Click Shield for Nucleo-144, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic

Step by step
Project 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 Water Detect 2 Click driver.
Key functions:
waterdetect2_get_fluid_status
- Water Detect 2 get fluid status function.waterdetect2_enable
- Water Detect 2 enable function.waterdetect2_disable
- Water Detect 2 disable 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 Water Detect 2 Click Example.
*
* # Description
* This library contains API for Water Detect 2 Click driver.
* Water Detect 2 Click is used for detecting water and other electroconductive liquids.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes driver and performs the default configuration.
*
* ## Application Task
* Reads fluid presence status and determines if there is fluid presence or not.
*
* @author Nenad Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "waterdetect2.h"
static waterdetect2_t waterdetect2; /**< Water Detect 2 Click driver object. */
static log_t logger; /**< Logger object. */
static uint8_t fluid_status_old = 2;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
waterdetect2_cfg_t waterdetect2_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.
waterdetect2_cfg_setup( &waterdetect2_cfg );
WATERDETECT2_MAP_MIKROBUS( waterdetect2_cfg, MIKROBUS_1 );
if ( DIGITAL_OUT_UNSUPPORTED_PIN == waterdetect2_init( &waterdetect2, &waterdetect2_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
waterdetect2_default_cfg( &waterdetect2 );
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
uint8_t fluid_status = waterdetect2_get_fluid_status( &waterdetect2 );
if ( fluid_status != fluid_status_old )
{
if ( WATERDETECT2_FLUID_DETECTED == fluid_status )
{
log_printf( &logger, " Fluid present! \r\n" );
}
else
{
log_printf( &logger, " No fluid present. \r\n" );
}
log_printf( &logger, "------------------- \r\n" );
fluid_status_old = fluid_status;
}
}
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