Oximeter 5 Click

Oximeter 5 Click is a compact add-on board suitable for measuring blood oxygen saturation. This board features the MAX30102, integrated pulse oximetry, and heart-rate monitor module from Analog Devices. The MAX30102 includes internal LEDs, photodetectors, optical elements, and low-noise electronics with ambient light rejection. It operates on a single 1.8V power supply acquired from both mikroBUS™ power rails for the internal LEDs, communicating through a standard I2C compatible interface. The MAX30102 can be shut down through software with zero standby current, allowing the power rails to remain powered at all times.

Click Product page

Click library

• Author : Nenad Filipovic
• Date : Nov 2021.
• Type : I2C type

Software Support

We provide a library for the Oximeter 5 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 Oximeter 5 Click driver.

Standard key functions :

• oximeter5_cfg_setup Config Object Initialization function.

  void oximeter5_cfg_setup ( oximeter5_cfg_t *cfg );

• oximeter5_init Initialization function.

  err_t oximeter5_init ( oximeter5_t *ctx, oximeter5_cfg_t *cfg );

• oximeter5_default_cfg Click Default Configuration function.

  err_t oximeter5_default_cfg ( oximeter5_t *ctx );

Example key functions :

• oximeter5_read_sensor_data Oximeter 5 get sensor data function.

  err_t oximeter5_read_sensor_data ( oximeter5_t *ctx, uint32_t *ir, uint32_t *red );

• oximeter5_get_oxygen_saturation Oximeter 5 get oxygen saturation function.

  err_t oximeter5_get_oxygen_saturation ( uint32_t *pun_ir_buffer, int32_t n_ir_buffer_length, uint32_t *pun_red_buffer, uint8_t *pn_spo2 );

• oximeter5_read_temperature Oximeter 5 read temperature function.

  err_t oximeter5_read_temperature ( oximeter5_t *ctx, float *temperature );

Example Description

This library contains API for Oximeter 5 Click driver. The demo application reads and calculate SpO2 oxygen saturation data.

The demo application is composed of two sections :

Application Init

Initializes I2C driver and log UART. After driver initialization the app set driver interface setup and default settings, buffer length of 100 stores 4 seconds of samples running at 25sps read the first 100 samples, and determine the signal range.

void application_init ( void ) 
{
    log_cfg_t log_cfg;              /**< Logger config object. */
    oximeter5_cfg_t oximeter5_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.
    oximeter5_cfg_setup( &oximeter5_cfg );
    OXIMETER5_MAP_MIKROBUS( oximeter5_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == oximeter5_init( &oximeter5, &oximeter5_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    Delay_ms ( 100 );

    if ( OXIMETER5_ERROR == oximeter5_default_cfg ( &oximeter5 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    Delay_ms ( 100 ); 

    un_brightness = 0;
    un_min = 0x3FFFF;
    un_max = 0;

    for ( uint8_t n_cnt = 0; n_cnt < 100; n_cnt++ )
    {
        while ( oximeter5_check_interrupt( &oximeter5 ) == OXIMETER5_INTERRUPT_ACTIVE );

        oximeter5_read_sensor_data( &oximeter5, &aun_red_buffer[ n_cnt ], &aun_ir_buffer[ n_cnt ] );

        if ( un_min > aun_red_buffer[ n_cnt ] )
        {
            un_min = aun_red_buffer[ n_cnt ];
        }

        if ( un_max < aun_red_buffer[ n_cnt ] )
        {
            un_max = aun_red_buffer[ n_cnt ];
        }
    }

    oximeter5_get_oxygen_saturation( &aun_ir_buffer[ 0 ], 100, &aun_red_buffer[ 0 ], &n_spo2 );
    log_info( &logger, " Application Task " );
    Delay_ms ( 100 ); 
}

Application Task

This is an example that demonstrates the use of the Oximeter 5 Click board™. In this example, display the IR and RED ADC data, and the SpO2 oxygen saturation data [ 0% - 100% ]. Results are being sent to the Usart Terminal where you can track their changes.

void application_task ( void ) 
{
    for ( uint8_t n_cnt = 25; n_cnt < 100; n_cnt++ )
    {
        aun_red_buffer[ n_cnt - 25 ] = aun_red_buffer[ n_cnt ];
        aun_ir_buffer[ n_cnt - 25 ] = aun_ir_buffer[ n_cnt ];

        if ( un_min > aun_red_buffer[ n_cnt ] )
        {
            un_min = aun_red_buffer[ n_cnt ];
        }

        if ( un_max < aun_red_buffer[ n_cnt ] )
        {
            un_max=aun_red_buffer[n_cnt];
        }
    }

    for ( uint8_t n_cnt = 75; n_cnt < 100; n_cnt++ )
    {
        un_prev_data = aun_red_buffer[ n_cnt - 1 ];
        while ( oximeter5_check_interrupt( &oximeter5 ) == OXIMETER5_INTERRUPT_ACTIVE ); 

        oximeter5_read_sensor_data( &oximeter5, &aun_red_buffer[ n_cnt ], &aun_ir_buffer[ n_cnt ] );

        if ( aun_red_buffer[ n_cnt ] > un_prev_data )
        {
            f_temp = aun_red_buffer[ n_cnt ]-un_prev_data;
            f_temp /= ( un_max - un_min );
            f_temp *= MAX_BRIGHTNESS;
            f_temp = un_brightness - f_temp;

            if ( f_temp < 0 )
            {
                un_brightness = 0;
            }
            else
            {
                un_brightness = ( uint32_t ) f_temp;
            }
        }
        else
        {
            f_temp = un_prev_data - aun_red_buffer[ n_cnt ];
            f_temp /= ( un_max - un_min );
            f_temp *= MAX_BRIGHTNESS;
            un_brightness += ( uint32_t ) f_temp;

            if ( un_brightness > MAX_BRIGHTNESS )
            {
                un_brightness = MAX_BRIGHTNESS;
            }
        }

        if ( ( OXIMETER5_OK == oximeter5_get_oxygen_saturation( &aun_ir_buffer[ 0 ], 100, &aun_red_buffer[ 0 ], &n_spo2 ) ) )
        {
            if ( aun_ir_buffer[n_cnt] > 10000  ) 
            {
                log_printf( &logger, "\tIR    : %lu \r\n", aun_ir_buffer[ n_cnt ] );
                log_printf( &logger, "\tRED   : %lu \r\n", aun_red_buffer[ n_cnt ] ); 
                log_printf( &logger, "- - - - - - - - - - - - - - -\r\n" );
                log_printf( &logger, "\tSPO2  : %d %%\r\n", ( uint16_t ) n_spo2 );
                log_printf( &logger, "-----------------------------\r\n" );
                Delay_ms ( 100 );       
            }
            else
            {
                Delay_ms ( 10 );      
            }
        }
    }
}

Note

A measurement time of at least 10 seconds is required for the SpO2 oxygen saturation data to be valid.

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.Oximeter5

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.