Library Description

Library performs the control of the Heart rate 6 Click board via I2C interface. Library offers a choice to perform a device configuration and a measurement wait time period, and then can read LED Data. For more details check documentation.

Key functions:

• void uint8_t heartrate6_writeSingleByte( uint8_t regAddr, uint8_t dataIn ) - Function writes one byte to the register.
• void uint8_t heartrate6_readBytes( uint8_t startAddr, uint8_t *dataOut, uint8_t nBytes ) - Function reads the desired number of bytes from the registers.

• void void heartrate6_getData( uint16_t *ledOffData, uint16_t *ledOnData ) - Function reads the LED Data as 16bit unsigned value.

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 configuration and reset. After that starts measurement.
• Application Task - (code snippet) - Waits until measurement cycle is finished and data is ready for reading. Then reads the LED Data values and performs the data plotting on serial plot, or logging on uart. Note : Uart baud rate should be as high as possible, then data plotting will be more better. I2C clock also should be 100kHz or greater, up to 400kHz, to get better results. The new measurement cycle is started when command for measurement starting is sent, or when register 0x57 is read out. Also the pressure on sensor must be same for the all measurement time, if we want to get the valid results. This is very important to device can work properly.

void applicationTask()
{
    heartrate6_waitMeasure();
    
    heartrate6_getData( &ledDataOFF, &ledDataON );

    plotRes( ledDataON );
}

Additional Functions :

• void plotRes( uint16_t plotData ) - Performs the data plotting on serial plot.
• void logRes() - Performs the data logging on uart.

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.