Library Description

The library can communicate with the device via I2C driver by writing to the registers and by reading from the registers, including data registers. The library has the ability to measure the level of oxygen (O2) in the blood, something like blood pressure. Library also can configure the device to works in two Time Slot Mode independently with different configurations. For more details check the documentation.

Key functions:

• uint8_t oxim_writeReg( uint8_t register_address, uint16_t transfer_data ) - The function writes 16-bit data to the register.
• uint8_t oxim_setTimeSlotA( uint8_t enableSlotA, uint8_t enablePhotodiode, uint8_t enableLED, uint8_t setMode ) - The function performs the configuration for Time Slot A and enables the interrupt for this Slot.
• uint8_t oxim_enableChannels( uint8_t selectChannel ) - The function determines which channel/channels be enabled.
• void oxim_readData( uint32_t *channResults, uint8_t resultMode ) - Function reads data in the desired mode for determined Slot.

Example description

The application is composed of three sections :

• System Initialization - Initializes peripherals and pins.
• Application Initialization - Initializes I2C driver and performs the device configuration which puts Time Slot Ain enabled mode and LEDX2 (IR diode) to the active state. On Oximeter click the photodiode is connected on PD1 input, and because we will observe the Channel 1 in this example (CH1 is enabled). Before the device configuration, the SW reset will be performed and in this way, we will put the registers in the initial state.
• Application Task - (code snippet) - Gets data when IR diode (LEDX2) is enabled, and after that gets data when LED diode(LEDX1) is enabled. Repeats operation 10 times and then calculates the average value for both results. This results logs on the serial plot as graphic view. Note: For this example you must have the serial plot aplication.The IR diode is internal connected on LEDX2 input, and the LED diode is internal connected on LEDX1 input.The photodiode is internal connected on PD1 input.When we want to perform some register configuration we must first put the device in Program Operating Mode, then we canset the desired register to the desired value, and when we finished, then we can put the device back to the Normal Operating Mode.

void applicationTask()
{
 oxim_plotDisplay();
}

Additional Functions :

• void oxim_plotDisplay() - Makes the average value of 10 samples when IR diode and LED diode is enabled alternately, and logs results on serial plot as graphic view.
• void oxim_uartDisplay() - Gets 100 samples of data when IR diode is enabled, and then gets 100 samples of data when LED diode is enabled and after that logs this 100 samples of data for both diode parallel on USB UART as graphic view.
• void oxim_logsResults() - Gets data which is determined in aplicationinit configuration and logs result on USB 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.