mikroelektronika/dac_click

Library for MCP4921

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DAC Click

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• CIC Prefix : DAC
• Author : Nenad Filipovic
• Verison : 1.0.0
• Date : Jul 2018.

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Software Support

We provide a library for the DAC 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

This is a sample program which demonstrates the use of the Microchip's MCP4921 12-bit D/A converter. This device accepts digital input (number from 0..4095 or procentage value from 0..100 %) and transforms it to the output voltage, ranging from 0..Vref and display log via UART. In this example the DAC communicates with MCU through the SPI communication.

Key functions :

• void dac_setOutVoltage( uint16_t valueDAC ) - Generic 12-bit data write function
• void dac_setOutputVoltageProcentage( uint8_t valueDACPct ) - Function write procentage value

Examples Description

The application is composed of three sections :

• System Initialization - Initializes CS pin as OUTPUT, SPI and LOG.
• Application Initialization - Initializes Driver enable's SPI and LOG.
• Application Task - (code snippet) In this example the DAC click communicates with MCU through the SPI communicationand and send:

1. data procentage value ( form 0 to 100 with step 20 [%]),
2. data 12-bit value ( form 0 to 4095 with step 1000 ), and transforms it to the output voltage, ranging from 0 to Vref [mV]

void applicationTask()
{
    char strDACValue[ 15 ];
    char strOutputVoltage[ 15 ];
    uint32_t valueDAC;
    uint8_t valueDACPct;

    mikrobus_logWrite("    ~ DAC Percentage Value ~",_LOG_LINE);
    mikrobus_logWrite("----------------------------------", _LOG_LINE);

    for ( valueDACPct = 0; valueDACPct < 101; valueDACPct += 20 )
    {
        dac_setOutputVoltageProcentage( valueDACPct );

        LongToStr( valueDACPct, strDACValue );

        mikrobus_logWrite( " Current DAC Value:", _LOG_TEXT );
        mikrobus_logWrite( strDACValue, _LOG_TEXT );
        mikrobus_logWrite( " %", _LOG_LINE );

        LongToStr( ( valueDACPct ) * 33 , strOutputVoltage );

        mikrobus_logWrite( " Output Voltage: ~ ", _LOG_TEXT );
        mikrobus_logWrite( strOutputVoltage, _LOG_TEXT );
        mikrobus_logWrite( " mV", _LOG_LINE );
        mikrobus_logWrite( "----------------------------------", _LOG_LINE );

        Delay_ms( 5000 );
    }

    mikrobus_logWrite( "##################################", _LOG_LINE );
    mikrobus_logWrite( "----------------------------------", _LOG_LINE );
    Delay_1sec();

    mikrobus_logWrite("    ~ DAC 12-bit Data Value ~",_LOG_LINE);
    mikrobus_logWrite("----------------------------------", _LOG_LINE);

    for ( valueDAC = 0; valueDAC < 4096; valueDAC += 1000 )
    {
        dac_setOutVoltage( valueDAC );

        LongToStr( valueDAC, strDACValue );

        mikrobus_logWrite( " Current DAC Value:", _LOG_TEXT );
        mikrobus_logWrite( strDACValue, _LOG_LINE );

        LongToStr( ( ( valueDAC ) * 220 ) / 273 , strOutputVoltage );

        mikrobus_logWrite( " Output Voltage: ~ ", _LOG_TEXT );
        mikrobus_logWrite( strOutputVoltage, _LOG_TEXT );
        mikrobus_logWrite( " mV", _LOG_LINE );
        mikrobus_logWrite( "----------------------------------", _LOG_LINE );

        Delay_ms( 5000 );
    }

    mikrobus_logWrite( "##################################", _LOG_LINE );
    mikrobus_logWrite( "----------------------------------", _LOG_LINE );
    Delay_1sec();
}

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

Other mikroE Libraries used in the example:

• SPI
• UART
• Conversion

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.

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