ADC 21 Click

ADC 21 Click is a compact add-on board that converts an analog voltage into a digital representation. This board features the ADC1283, a low-power, eight-channel pure CMOS 12-bit analog-to-digital converter from STMicroelectronics. The ADC1283 is specified for conversion from 50ksps to 200ksps. Its architecture is based on a successive approximation register with an internal track-and-hold cell. It features eight single-ended multiplexed inputs, where the output serial data is straight binary and SPI-compatible.

Click Product page

Click library

• Author : Stefan Filipovic
• Date : Jan 2023.
• Type : SPI type

Software Support

We provide a library for the ADC 21 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 from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for ADC 21 Click driver.

Standard key functions :

• adc21_cfg_setup Config Object Initialization function.

  void adc21_cfg_setup ( adc21_cfg_t *cfg );

• adc21_init Initialization function.

  err_t adc21_init ( adc21_t *ctx, adc21_cfg_t *cfg );

Example key functions :

• adc21_read_raw_adc This function reads raw ADC value from the selected channel by using SPI serial interface.

  err_t adc21_read_raw_adc ( adc21_t *ctx, uint8_t channel, uint16_t *raw_adc );

• adc21_read_voltage This function reads raw ADC value from the selected channel and converts it to proportional voltage level depending on the avcc selection.

  err_t adc21_read_voltage ( adc21_t *ctx, uint8_t channel, float avcc, float *voltage );

Example Description

This example demonstrates the use of ADC 21 Click board by reading and displaying the voltage levels from 8 analog input channels.

The demo application is composed of two sections :

Application Init

Initializes the driver and logger.

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    adc21_cfg_t adc21_cfg;  /**< Click config object. */

    /** 
     * 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.
    adc21_cfg_setup( &adc21_cfg );
    ADC21_MAP_MIKROBUS( adc21_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == adc21_init( &adc21, &adc21_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    log_info( &logger, " Application Task " );
}

Application Task

Reads the voltage levels from all 8 analog input channels and displays the results on the USB UART once per second approximately.

void application_task ( void )
{
    static uint8_t ch_num = ADC21_CHANNEL_0;
    float ch_voltage;
    if ( ADC21_OK == adc21_read_voltage ( &adc21, ch_num, ADC21_AVCC_3V3, &ch_voltage ) )
    {
        log_printf ( &logger, " CH%u voltage: %.2f V\r\n", ( uint16_t ) ch_num, ch_voltage );
    }
    if ( ++ch_num > ADC21_CHANNEL_7 )
    {
        log_printf ( &logger, " ------------------------\r\n\n" );
        ch_num = ADC21_CHANNEL_0;
        Delay_ms ( 1000 );
    }
}

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.ADC21

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. UART terminal is available in all MikroElektronika compilers.