Intermediate
30 min

Unlock the potential of ISO 9141 with L9637 and PIC18F57Q43

Monolithic bus driver with ISO 9141 interface

ISO 9141 Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

ISO 9141 Click

Dev Board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

Utilize the bidirectional serial communication capability, compliant with the ISO9141 standard, to enable effective diagnostics in automotive systems

A

A

Hardware Overview

How does it work?

ISO 9141 Click is based on the L9637, a monolithic bus driver designed to provide bidirectional serial communication in automotive diagnostic applications according to the specification "Diagnostic Systems ISO9141" from ST Microelectronics. The L9637 is also known as the K-Line Transceiver that provides a bidirectional link, called K, and a separate comparator, called L, to the related diagnosis bus that can be connected to a terminal labeled K and L on this Click board™. The K and L pins are protected against overvoltages and reverse battery conditions. All pins show high impedance characteristics during the lack of power supply or ground. The L9637 has a wide supply voltage range from 4.5V to 36V and several modes of operation like Standby Mode with low current consumption and overtemperature Shut-Down Mode. The overtemperature Shut-Down Mode switches OFF

the K output if the L9637's temperature increases above the thermal shut-down threshold. To reactivate K again, the temperature must decrease below the K switch ON temperature value. The outputs will be switched OFF and stay at high impedance to achieve no fault for the power supply undervoltage conditions. ISO 9141 Click communicates with MCU using the UART interface with the default baud rate of 9600bps and commonly used UART RX and TX pins for the data transfer. The UART input TX and output RX of K are associated with the logic voltage level from mikroBUS™ (VCC) with its integrated pull-up resistances. Also, the L comparator output pin LO has a pull-up resistance connected to VCC. All bus-defined inputs, L and K, have supply voltage-dependent thresholds and sufficient hysteresis to suppress line spikes. This Click board™ is easy to program because it does not require an

overly demanding configuration. Only what is necessary for the errorless work is the selection of the appropriate mode of operation, whether the Click board™ will work as a receiver or transmitter. In this way, the transmitter will send the data every 2 seconds while the receiving side will receive the data in a "byte-by-byte "format. This can also be seen in an example code that contains easy-to-use functions that may be used as a reference for further development. This Click board™ is designed to be operated with both 3.3V and 5V logic voltage levels that can be selected via VCC SEL jumper. This allows both 3.3V and 5V capable MCUs to use the UART 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.

ISO 9141 Click hardware overview image

Features overview

Development board

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.

PIC18F57Q43 Curiosity Nano double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

48

RAM (Bytes)

8196

You complete me!

Accessories

Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.

Curiosity Nano Base for Click boards accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
UART TX
PC3
TX
UART RX
PC2
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

ISO 9141 Click Schematic schematic

Step by step

Project assembly

Curiosity Nano Base for Click boards front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F57Q43 as your development board.

Curiosity Nano Base for Click boards front image hardware assembly
Charger 27 Click front image hardware assembly
PIC18F47Q10 Curiosity Nano front image hardware assembly
Prog-cut hardware assembly
Charger 27 Click complete accessories setup image hardware assembly
Curiosity Nano with PICXXX 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 image step 5 hardware assembly
Necto image step 6 hardware assembly
PIC18F57Q43 Curiosity MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware 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 ISO 9141 Click driver.

Key functions:

  • iso9141_generic_write - This function writes a desired number of data bytes by using UART serial interface

  • iso9141_generic_read - This function reads a desired number of data bytes by using UART serial interface

  • iso9141_send_data - This function send data

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 ISO 9141 Click Example.
 *
 * # Description
 * This example demonstrates the use of an ISO 9141 click board by showing
 * the communication between the two click boards.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initalizes device and makes an initial log.
 * 
 * ## Application Task
 * Depending on the selected application mode, it reads all the received data or 
 * sends the desired text message once per second.
 *
 * @author MikroE Team
 *
 */

#include "board.h"
#include "log.h"
#include "iso9141.h"

// Comment out the line below in order to switch the application mode to receiver
#define DEMO_APP_TRANSMITTER

// Text message to send in the transmitter application mode
#define DEMO_TEXT_MESSAGE           "MIKROE - ISO 9141 click board\r\n\0"

static iso9141_t iso9141;
static log_t logger;

void application_init ( void )
{
    iso9141_cfg_t iso9141_cfg;
    log_cfg_t logger_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( logger_cfg );
    log_init( &logger, &logger_cfg );
    log_info( &logger, " Application Init " );
    
    // Click initialization.
    iso9141_cfg_setup( &iso9141_cfg );
    ISO9141_MAP_MIKROBUS( iso9141_cfg, MIKROBUS_1 );
    if ( UART_ERROR == iso9141_init( &iso9141, &iso9141_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
#ifdef DEMO_APP_TRANSMITTER
    log_printf( &logger, " Application Mode: Transmitter\r\n" );
#else
    log_printf( &logger, " Application Mode: Receiver\r\n" );
#endif
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
#ifdef DEMO_APP_TRANSMITTER
    iso9141_generic_write( &iso9141, DEMO_TEXT_MESSAGE, strlen( DEMO_TEXT_MESSAGE ) );
    log_printf( &logger, "%s", ( char * ) DEMO_TEXT_MESSAGE );
    Delay_ms ( 1000 ); 
#else
    uint8_t rx_byte = 0;
    if ( 1 == iso9141_generic_read( &iso9141, &rx_byte, 1 ) )
    {
       log_printf( &logger, "%c", rx_byte );
    }
#endif
}

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
/*!
 * @file main.c
 * @brief ISO 9141 Click Example.
 *
 * # Description
 * This example demonstrates the use of an ISO 9141 click board by showing
 * the communication between the two click boards.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initalizes device and makes an initial log.
 * 
 * ## Application Task
 * Depending on the selected application mode, it reads all the received data or 
 * sends the desired text message once per second.
 *
 * @author MikroE Team
 *
 */

#include "board.h"
#include "log.h"
#include "iso9141.h"

// Comment out the line below in order to switch the application mode to receiver
#define DEMO_APP_TRANSMITTER

// Text message to send in the transmitter application mode
#define DEMO_TEXT_MESSAGE           "MIKROE - ISO 9141 click board\r\n\0"

static iso9141_t iso9141;
static log_t logger;

void application_init ( void )
{
    iso9141_cfg_t iso9141_cfg;
    log_cfg_t logger_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( logger_cfg );
    log_init( &logger, &logger_cfg );
    log_info( &logger, " Application Init " );
    
    // Click initialization.
    iso9141_cfg_setup( &iso9141_cfg );
    ISO9141_MAP_MIKROBUS( iso9141_cfg, MIKROBUS_1 );
    if ( UART_ERROR == iso9141_init( &iso9141, &iso9141_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
#ifdef DEMO_APP_TRANSMITTER
    log_printf( &logger, " Application Mode: Transmitter\r\n" );
#else
    log_printf( &logger, " Application Mode: Receiver\r\n" );
#endif
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
#ifdef DEMO_APP_TRANSMITTER
    iso9141_generic_write( &iso9141, DEMO_TEXT_MESSAGE, strlen( DEMO_TEXT_MESSAGE ) );
    log_printf( &logger, "%s", ( char * ) DEMO_TEXT_MESSAGE );
    Delay_ms ( 1000 ); 
#else
    uint8_t rx_byte = 0;
    if ( 1 == iso9141_generic_read( &iso9141, &rx_byte, 1 ) )
    {
       log_printf( &logger, "%c", rx_byte );
    }
#endif
}

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

Additional Support

Resources

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