Library Description

The library covers necessary functions that enables the usage of the Current Limit click board. User can check or set current limit or enable/disable the device.

Key functions:

• void currentlimit_dev_enable ( uint8_t state ); - Function is used to enable or disable the device.
• void currentlimit_set_limit ( uint8_t lim_val ); - Function is used to set the current limit with predefined values.
• void currentlimit_set_limit_calc ( float lim_val ); - Function is used to set the current limit with calculacion.

Examples description

The application is composed of three sections :

• System Initialization - Initializes SPI module, LOG structure, sets CS and AN pins as output.
• Application Initialization - Initalizes SPI driver and enables the device.
• Application Task - This example shows capabilities of Current Limit Click board by reading users input from USART terminal and using it as an index for an array of pre-calculated values that define current limit level(consult "Values definitions").
• Values definitions - By using calculation from datasheet for MAX890 ( 6th page ) the following values were derived: 1 - 223 - 0.1A 2 - 241 - 0.2A 3 - 247 - 0.3A 4 - 250 - 0.4A 5 - 252 - 0.5A 6 - 253 - 0.6A 7 - 254 - 0.7A 8 - 255 - 0.867A

void application_task ( )
{
    char inx;

    if ( UART_Rdy_Ptr() )
    {
        inx = UART_Rd_Ptr( );
        inx -=48;
        currentlimit_set_limit( lim_val[ inx - 1 ] );
        mikrobus_logWrite("Data sent successfully!", _LOG_LINE );
    }
}

Other mikroE Libraries used in the example:

• SPI
• UART

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.