4-20 mA R Click

4-20mA R Click is an add-on board in mikroBUS form factor which serves as a receiver in a 4-20mA current loop standard. It features INA196 current shunt monitor, MCP3201 12-bit ADC as well as TPS61041 DC/DC boost converter.

Click Product page

Click library

• Author : MikroE Team
• Date : Jan 2020.
• Type : SPI type

Software Support

We provide a library for the 420MaR Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly form compilers IDE(recommended way), or downloaded from our LibStock, or found on mikroE github account.

Library Description

This library contains API for 420MaR Click driver.

Standard key functions :

• Config Object Initialization function.

  void c420mar_cfg_setup ( c420mar_cfg_t *cfg );

• Initialization function.

  c420MAR_RETVAL c420mar_init ( c420mar_t ctx, c420mar_cfg_t cfg );

• Click Default Configuration function.

  void c420mar_default_cfg ( c420mar_t *ctx );

Example key functions :

• This function reads the 16-bit current value from the SPI data register, and then normalizes and converts it to float.

  float c420mar_read_data( c420mar_t *ctx );

Examples Description

This example showcases how to initialize, configure and use the 4-20 mA R Click. It is a simple SPI communication module that acts as a receiver in a 4-20 current loop. The Click reads current data and converts the analog signal to a digital 12-bit format.

The demo application is composed of two sections :

Application Init

This function initializes and configures the logger and Click modules.

void application_init ( )
{
    log_cfg_t log_cfg;
    c420mar_cfg_t 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( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, "---- Application Init ----" );

    //  Click initialization.

    c420mar_cfg_setup( &cfg );
    c420MAR_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    c420mar_init( &c420mar, &cfg );
}

Application Task

This function reads and displays current data every half a second.

void application_task ( )
{
    float current;

    current = c420mar_read_data( &c420mar );

    log_printf( &logger, "-----------------------------\r\n" );
    log_printf( &logger, " * Current: %.3f mA * \r\n", current );

    Delay_ms ( 500 );
} 

The full application code, and ready to use projects can be installed directly form compilers IDE(recommneded) or found on LibStock page or mikroE GitHub accaunt.

Other mikroE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.420MaR

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.