Intermediate
30 min
0

Achieve precise RF signal management with MASWSS0115 and PIC18LF45K22

Transforming the RF landscape

RF Switch Click with EasyPIC v7a

Published Sep 23, 2023

Click board™

RF Switch Click

Development board

EasyPIC v7a

Compiler

NECTO Studio

MCU

PIC18LF45K22

Our RF switch solution empowers engineers with a versatile tool for selecting and routing RF signals, enhancing system flexibility and signal quality

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Hardware Overview

How does it work?

RF Switch Click is based on the MASWSS0115, a GaAs PHEMT MMIC single-pole, double-throw (SPDT) switch from Macom in a low cost, lead-free SC-70 (SOT-363) surface mount plastic package. The MASWSS0115 is ideally suited for applications where a very small size and low cost are required. Typical applications are dual-band systems that require switching between small signal components such as filter banks, single-band LNAs, converters, etc. This part can be used for low power, low loss requirements in all systems operating up to 3 GHz, including PCS, GSM, DCS, Bluetooth, and other receive chain applications.

The MASWSS0115 is fabricated using a 0.5 micron gate length GaAs PHEMT process. The process features full passivation for performance and reliability. Featured chip MASWSS0115 provides signal switching of 50MHz to up to 3GHz with an insertion loss of 0.3 dB at 2.4 GHz and power consumption of 5 µA at +2.3V. Ultra High-Speed CMOS inverter labeled as NC7WZ14 is used for driving and controlling an RF switch with the typical switching time of 3,2 ns. Additionally, a load switch TPS22943 can enable or disable the RF switch by electrically detaching the power supply. RF Switch click uses the 5V to supply the

switch driver while 3.3V microcontroller can be used to communicate with the control circuitry. Two LEDs (RF1 and RF2) indicate the current active RF port as a visual representation of a state of the switch. Since RF1 is complementary to RF2, the switching can be achieved with only one GPIO pin. The RFC is an input of the switch with the possibility of redirecting the RF signal to RF1 or RF2 port. Besides switching SEL pin, the pin labeled as ON is used for power control. All of the switch ports are accessible on the connectors located on top of the click board with the addition of miniature coaxial connectors for both RF ports.

RF Switch Click top side image
RF Switch Click bottom side image

Features overview

Development board

EasyPIC v7a is the seventh generation of PIC development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has a broad set of unique functions, such as the first-ever embedded debugger/programmer over USB-C. The development board is well organized and designed so that the end-user has all the necessary elements in one place, such as switches, buttons, indicators, connectors, and others. With four different connectors for each port, EasyPIC v7a allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of the EasyPIC v7a 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 various external power sources, including an external 12V power supply, 7-23V AC or 9-32V DC via DC connector/screw terminals, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART and RS-232 are also included, alongside the well-

established mikroBUS™ standard, three display options (7-segment, graphical, and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from PIC10F, PIC12F, PIC16F, PIC16Enh, PIC18F, PIC18FJ, and PIC18FK families. EasyPIC v7a 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.

EasyPIC v7a double side image

Microcontroller Overview

MCU Card / MCU

PIC18LF45K22

Architecture

PIC

MCU Memory (KB)

32

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

1536

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
Power On
RE0
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
NC
NC
3.3V
Ground
GND
GND
Port Selection
RC0
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

RF Switch Click Schematic schematic

Step by step

Project assembly

EasyPIC v7a front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v7a as your development board.

EasyPIC v7a front image hardware assembly
GNSS2 Click front image hardware assembly
MCU DIP 40 hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
EasyPIC v7a 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 DIP image step 7 hardware assembly
EasyPIC PRO v7a Display Selection Necto Step 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 RF Switch Click driver.

Key functions:

  • rfswitch_power_on - RF Switch power on function

  • rfswitch_switch_channel - RF Switch switch channel function

  • rfswitch_select_channel - RF Switch select channel function.

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 RF Switch Click Example.
 *
 * # Description
 * This is an example that demonstrates the use of the RF Switch Click board.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization driver enable's - GPIO, also write log and powers on device.
 *
 * ## Application Task
 * Waiting for valid user input and executes functions based on set of valid commands.
 * Results are being sent to the Usart Terminal where you can track their changes.
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "rfswitch.h"

static rfswitch_t rfswitch;   /**< RF Switch Click driver object. */
static log_t logger;    /**< Logger object. */

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    rfswitch_cfg_t rfswitch_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.
    rfswitch_cfg_setup( &rfswitch_cfg );
    RFSWITCH_MAP_MIKROBUS( rfswitch_cfg, MIKROBUS_1 );
    if ( DIGITAL_OUT_UNSUPPORTED_PIN == rfswitch_init( &rfswitch, &rfswitch_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    log_printf( &logger, "------------------------\r\n" );
    log_printf( &logger, "   Powering device on   \r\n" );
    rfswitch_power_on( &rfswitch );
    Delay_ms( 100 );
    log_printf( &logger, "------------------------\r\n" );
    log_printf( &logger, "   Select option to     \r\n" );
    log_printf( &logger, "    select channel      \r\n" );
    log_printf( &logger, "------------------------\r\n" );
    log_printf( &logger, " 1. Channel 1 selected  \r\n" );
    log_printf( &logger, " 2. Channel 2 selected  \r\n" );
    log_printf( &logger, " 3. Switching channel   \r\n" );
    log_printf( &logger, "------------------------\r\n" );
}

void application_task ( void ) 
{
    uint8_t tx_buf;
    if ( log_read( &logger, &tx_buf, 1 ) ) {
        switch ( tx_buf ) {
            case '1' : {
                rfswitch_select_channel( &rfswitch, RFSWITCH_SELECT_CHANNEL_1 );
                log_printf( &logger, " Switching to RF port 1 \r\n" );
                log_printf( &logger, "------------------------\r\n" );
                break;
            }
            case '2' : {
                rfswitch_select_channel( &rfswitch, RFSWITCH_SELECT_CHANNEL_2 );
                log_printf( &logger, " Switching to RF port 2 \r\n" );
                log_printf( &logger, "------------------------\r\n" );
                break;
            }
            case '3' : {
                rfswitch_switch_channel( &rfswitch );
                log_printf( &logger, "   Switching RF port    \r\n" );
                log_printf( &logger, "------------------------\r\n" );
                break;
            }
            default : {
                log_printf( &logger, "   Select option to     \r\n" );
                log_printf( &logger, "    select channel      \r\n" );
                log_printf( &logger, "------------------------\r\n" );
                log_printf( &logger, " 1. Channel 1 selected  \r\n" );
                log_printf( &logger, " 2. Channel 2 selected  \r\n" );
                log_printf( &logger, " 3. Switching channel   \r\n" );
                log_printf( &logger, "------------------------\r\n" );
            }
        }
    }
}

void main ( void ) 
{
    application_init( );

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

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

Additional Support

Resources