Library Description

Library performs the control of the HeartRate 8 Click board. Library offers a choice to communicate with the device by using I2C interface and driver functions. Functions perform register writing and reading operations, GREEN and IR LED control, LED data reading, device configuration... For more details check documentation.

Key functions:

• uint8_t heartrate8_writeSingleByte( uint8_t regAddr, uint8_t dataIn ) - Function writes one byte to the register.
• uint8_t heartrate8_readBytes( uint8_t startAddr, uint8_t *dataOut, uint8_t nBytes ) - Function reads the desired number of bytes from the registers.

• uint8_t heartrate8_getData( uint8_t dataSelect, uint16_t *ledOutON, uint16_t *ledOutOFF ) - Function gets the selected data from the determined LED Data registers.

Examples description

The application is composed of the three sections :

• System Initialization - Initializes peripherals and pins.
• Application Initialization - Initializes I2C interface and performs the device reset, after which the device configuration can be performed. The device is configured to work in Single Measurement Mode with LED pulsing. The driver which is selected is driver for the GREEN LED Data.
• Application Task - (code snippet) - Sends command to start measurement cycle, then waits until measurement cycle is finished. When measurement cycle is done, gets LED ON and LED OFF Data for the selected LED driver (GREEN or IR LED) and performs data plotting on serial plotter every 35ms.

void applicationTask()
{
    heartrate8_startMeasure();
    intCheck = heartrate8_checkInt();
    
    while (intCheck != _HEARTRATE8_INT_ACTIVE)
    {
        intCheck = heartrate8_checkInt();
    }    
    
    heartrate8_getData( _HEARTRATE8_GREEN_DATA_GET, &ledDataON, &ledDataOFF );
    plotRes( ledDataON );
    intCheck = heartrate8_intClear();
}

Additional Functions :

• void plotRes( uint16_t plotData )   - Performs data plotting on serial plotter.
• void logRes()   - Performs LED Data logging on uart terminal.

Other mikroE Libraries used in the example:

• Conversions
• I2C
• UART

Additional notes and information

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.