• CIC Prefix : OBDII
• Author : MikroE Team
• Verison : 1.0.0
• Date : Nov 2017.

We provide a library for the OBD_II Click on our LibStock page, as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Library Description

Library carries generic functions, neccesasry for communication with the module.

Key functions :

• obdII_sendCommand - Sending provided command to the module
• obdII_readResponse - Reads current response inside buffer
• obdII_process - State machine function. This function calles frequently.

Examples Description

Example demnstrates how to read RPM from your vecihle.

• System Initialization - Intializes UART module and GPIO pins
• Application Initialization - Power on module and seting it to Automatic protocol detection by sending "ATSP0"
• Application Task - (code snippet) - Sequential send command for RPM and converts readed response to RPM depend on

void applicationTask()
{
    uint8_t tmp[ 25 ];

    obdII_sendCommand( &RPM_CMD[0] );
    while( !obdII_responseReady() )
        ;
    obdII_readResponse( &rsp[0] );

    memcpy( &tmp[0], &rsp[11], 4 );
    tmp[5] = 0;
    rpm = xtoi( &tmp[0] );
    rpm = rpm / 4;
    WordToStr(rpm, &tmp[0]);

    mikrobus_logWrite( "Current RPM : ", _LOG_TEXT );
    mikrobus_logWrite( tmp, _LOG_LINE );
}

Note that not all vechiles uses same set of commands - so it might happens that routine for reading RPM on your vecihle is not same as these one provided inside example.

The full application code, and ready to use projects can be found on our LibStock page.

Other mikroE Libraries used in the example:

• Conversions
• String
• Stdlib

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all Mikroelektronika compilers, or any other terminal application of your choice, can be used to read the message.