30 min

Create a load-switching solution with L9026 and PIC18F86J50

Save your energy when a load isn't needed

SolidSwitch 2 Click with Fusion for PIC v8

Published Mar 06, 2023

Click board™

SolidSwitch 2 Click

Development board

Fusion for PIC v8


NECTO Studio



Provide power across different loads with individual control of each one



Hardware Overview

How does it work?

SolidSwitch 2 Click is based on the L9026, an automotive multi-channel relay driver optimized for automotive relay and LED applications from STMicroelectronics. Eight channels of the L9026 represent two high-side and six configurable high-side/low-side drivers, which can be driven by an SPI interface or by two dedicated parallel inputs (IN0 and IN1 pins routed to the PWM and INT pins of the mikroBUS™ socket). Operating from an external power supply from 3V up to 18V, it provides a maximum current of 1A on its output terminals. This board is an excellent choice for automotive, resistive, and inductive applications (LEDs and relays) and capacitive loads.

As mentioned, this Click board™ communicates with MCU through a standard SPI interface to control and configure the loads and the device. The L9026 also offers advanced diagnostic and protection features such as short-to-ground, open load, overcurrent, and overtemperature detections, with status feedback of all diagnostic functions provided via the SPI interface. Besides, the L9026 also features Idle mode for reduced current consumption, controlled via IDL pin routed to the AN pin of the mikroBUS™ socket and the “Limp home” mode. This mode allows using two selected drivers in particularly faulty conditions, such as SPI fault, micro fault, or supply undervoltage.

The device can guarantee operations under a cranking scenario with a supply voltage down to 3V, ensuring a low quiescent current under reset conditions. 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

Fusion for PIC 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 PIC, dsPIC, PIC24, and PIC32 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, Fusion for PIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the Fusion for PIC v8 development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board 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 are also included, including the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options (graphical and character-based LCD). Fusion for PIC 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.

Fusion for PIC v8 horizontal image

Microcontroller Overview

MCU Card / MCU



8th Generation



MCU Memory (KB)


Silicon Vendor


Pin count


RAM (Bytes)


Used MCU Pins

mikroBUS™ mapper

Idle Mode
SPI Chip Select
SPI Clock
Power Supply
Parallel Command 0
Parallel Command 1
Power Supply

Take a closer look


SolidSwitch 2 Click Schematic 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 Fusion for PIC v8 as your development board.

Fusion for PIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
v8 SiBRAIN Access MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

Track your results in real time

Application Output

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

UART Application Output Step 1

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

UART Application Output Step 2

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

UART Application Output Step 3

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART Application Output Step 4

Software Support

Library Description

This library contains API for SolidSwitch 2 Click driver.

Key functions:

  • solidswitch2_write_register This function writes a desired data to the selected register by using SPI serial interface.

  • solidswitch2_toggle_in0_pin This function toggles the IN0 pin logic state.

  • solidswitch2_toggle_in1_pin This function toggles the IN1 pin logic state.

Open Source

Code example

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

 * @file main.c
 * @brief SolidSwitch 2 Click example
 * # Description
 * This example demonstrates the use of SolidSwitch 2 click board by controlling the output state.
 * The demo application is composed of two sections :
 * ## Application Init
 * Initializes the driver and performs the click default configuration which maps outputs as follows:
 * OUT2   - IN0,
 * OUT3   - IN1,
 * OUT4-5 - PWM GEN,
 * OUT6-7 - PWM LED.
 * ## Application Task
 * Changes the PWM GEN (max to min) and PWM LED (min to max) duty cycle and toggles the IN0 and IN1
 * pins every 250ms. The duty cycle values and INx toggle messages will be displayed on the USB UART.
 * @author Stefan Filipovic

#include "board.h"
#include "log.h"
#include "solidswitch2.h"

static solidswitch2_t solidswitch2;
static log_t logger;

void application_init ( void )
    log_cfg_t log_cfg;  /**< Logger config object. */
    solidswitch2_cfg_t solidswitch2_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.
    solidswitch2_cfg_setup( &solidswitch2_cfg );
    SOLIDSWITCH2_MAP_MIKROBUS( solidswitch2_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == solidswitch2_init( &solidswitch2, &solidswitch2_cfg ) )
        log_error( &logger, " Communication init." );
        for ( ; ; );
    if ( SOLIDSWITCH2_ERROR == solidswitch2_default_cfg ( &solidswitch2 ) )
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    log_info( &logger, " Application Task " );

void application_task ( void )
    for ( uint16_t duty_cycle = SOLIDSWITCH2_MIN_DUTY_CYCLE; duty_cycle <= SOLIDSWITCH2_MAX_DUTY_CYCLE; duty_cycle += 5 )
        if ( SOLIDSWITCH2_OK == solidswitch2_write_register ( &solidswitch2, SOLIDSWITCH2_REG_PWM_GEN_DC, 
                                                              ( uint8_t ) ( SOLIDSWITCH2_MAX_DUTY_CYCLE - duty_cycle ) ) )
            log_printf ( &logger, " PWM GEN DC: %u\r\n", ( SOLIDSWITCH2_MAX_DUTY_CYCLE - duty_cycle ) );
        if ( SOLIDSWITCH2_OK == solidswitch2_write_register ( &solidswitch2, SOLIDSWITCH2_REG_PWM_LED_DC, ( uint8_t ) duty_cycle ) )
            log_printf ( &logger, " PWM LED DC: %u\r\n", duty_cycle );
        solidswitch2_toggle_in0_pin ( &solidswitch2 );
        log_printf ( &logger, " Toggle IN0 pin\r\n" );
        solidswitch2_toggle_in1_pin ( &solidswitch2 );
        log_printf ( &logger, " Toggle IN1 pin\r\n\n" );
        Delay_ms ( 250 );

void main ( void )
    application_init( );

    for ( ; ; )
        application_task( );

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

Additional Support