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Heart rate 3 click
From MikroElektonika Documentation
Heart Rate 3 click is a mikroBUS™ add-on board whose functionality is determined by two
components: an OSRAM’s SFH7050 pulse oximetry and heart rate monitoring module, and a TI
AFE4404 (analong-front-end) IC specialized for bio-sensing.
Heart rate 3 click
Features and usage notes
Heart Rate 3 click is a mikroBUS™ add-on
board whose functionality is determined by
two components: an OSRAM’s SFH7050
pulse oximetry and heart rate monitoring
module, and a TI AFE4404 (analong-front-
end) IC specialized for bio-sensing.
The SFH7050 multichip package contains 3
LEDs and one photodiode separated with a
light barrier to prevent optical crosstalk. When
the three LEDs shine through a subject’s
finger, some of the light is absorbed by the
pulsating blood.
Heart rate 3 click
IC/Module
AFE4404
(http://www.ti.com/lit/ds/symlink/afe4404.pdf)
SFH7050 (http://www.osram-
os.com/media/resource/HIRES/541656/246267/light-
is-wearable---flysheet-biomon-sensor-sfh-7050-
gb.pdf)
Interface
Power
supply
Website
I2C
3.3V
www.mikroe.com/click/heart-rate-3
(http://www.mikroe.com/click/heart-rate-3)
The analog reading from the SFH7050 is
forwarded to the AFE chip that is able to
derive pulse readings from the intensity of the reflected light.
AFE4404 is highly-configurable and adaptable for different usage scenarios (different lighting
conditions or skin tones) making Heart Rate 3 click a robust heart rate monitoring solution.
The board communicates with the target MCU through the mikroBUS™ I2C interface, with
additional functionality provided by RST, CLK and RDY pins.
Heart Rate 3 click works on a 3.3V power supply, but an onboard jumper allows you to set the
voltage for driving the SFH7050 LEDs at either 3.3V or 5V.
Schematic also available in PDF (http://cdn-
docs.mikroe.com/images/d/d1/Heart_Rate_3_click_sc
Programming
Setting up of Heartrate 3 click and external interrupt to read values at 100hz and using an algorithm to find a heartrate.
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#include
<stdint.h>
#include
"heartrate_3.h"
#include
"resources.h"
// HeartRate 3 GPIO
sbit RST at GPIOC_ODR.B2;
void
system_setup(
void
);
void
setup_interrupt();
char
uart_text[20]
=
{0};
uint64_t
int_count
= 0;
//Used by timer to calibrate sampling freq.
void
main()
{
//Local Declarations
uint16_t
rate
= 0;
char
txt[15]
=
{0};
system_setup();
Delay_ms(200);
initStatHRM();
setup_interrupt();
// GPIO / HeartRate 3 / UART / I2C Setups
// Initializes values to 0
// Setup interrupt handler
while(1)
{
rate
=
hr3_get_heartrate();
IntToStr( rate, uart_text );
UART1_Write_Text( uart_text );
UART1_Write_Text(
"\r\n"
);
}
}
void
system_setup(
void
)
{
//Local Declarations
char
text[40]
=
{
0
};
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dynamic_modes_t dynamic_modes;
uint8_t
address
= 0x58;
//Set up dynamic modes for Heart Rate 3 Initialization
dynamic_modes.transmit
=
trans_dis;
//Transmitter disabled
dynamic_modes.curr_range
=
led_double;
//LED range 0 - 100
dynamic_modes.adc_power
=
adc_on;
//ADC on
dynamic_modes.clk_mode
=
osc_mode;
//Use internal Oscillator
dynamic_modes.tia_power
=
tia_off;
//TIA off
dynamic_modes.rest_of_adc
=
rest_of_adc_off;
//Rest of ADC off
dynamic_modes.afe_rx_mode
=
afe_rx_normal;
//Normal Receiving on AFE
dynamic_modes.afe_mode
=
afe_normal;
//Normal AFE functionality
//GPIO setup
GPIO_Digital_Output(
&GPIOC_BASE,
_GPIO_PINMASK_2 );
GPIO_Digital_Input(
&GPIOA_BASE,
_GPIO_PINMASK_0 );
GPIO_Digital_Input(
&GPIOD_BASE,
_GPIO_PINMASK_10 );
//UART Initialize
UART1_Init(
9600
);
UART1_Write_Text(
"UART is Initialized\r\n"
);
//Toggle Reset pin
RST
= 0;
Delay_us(50);
RST
= 1;
//I2C Initialize
I2C1_Init_Advanced(
400000, &_GPIO_MODULE_I2C1_PB67
);
UART1_Write_Text(
"I2C Initialized\r\n"
);
//Heart Rate 3 Initialize
hr3_init( address,
&dynamic_modes
);
}
void
setup_interrupt()
{
GPIO_Digital_Output(&GPIOE_BASE, _GPIO_PINMASK_HIGH);
GPIOE_ODR
= 0xAAAA;
GPIO_Digital_Input(&GPIOD_BASE, _GPIO_PINMASK_10);
RCC_APB2ENR.AFIOEN
= 1;
AFIO_EXTICR3
= 0x0300;
EXTI_RTSR
= 0x00000400;
EXTI_IMR
|= 0x00000400;
NVIC_IntEnable(IVT_INT_EXTI15_10);
EnableInterrupts();
//
//
//
//
//
//
// Enable digital output on PORTD
}
Enable clock for alternate pin functions
PD10 as External interrupt
Set interrupt on Rising edge
Set mask
Enable External interrupt
Enables the processor interrupt.
void
ExtInt()
iv IVT_INT_EXTI15_10 ics ICS_AUTO {
EXTI_PR.B10
= 1;
// clear flag
int_count++;
statHRMAlgo( hr3_get_led1_amb1_val() );
// Give led1 ambient value to heartrate function. ( 100 times a second )
}
Code examples that demonstrate the usage of Heart rate 3 click with MikroElektronika hardware, written for mikroC for ARM, AVR, dsPIC, FT90x, PIC and
PIC32 are available on Libstock (http://libstock.mikroe.com/projects/view/1908/heart-rate-3-click).
Resources
- Learn article explaining Heart rate 3 click library (http://learn.mikroe.com/microcontrollers-have-a-heart-too/)
- Libstock Heart rate 3 click example (http://libstock.mikroe.com/projects/view/1908/heart-rate-3-click)
Retrieved from "http://docs.mikroe.com/index.php?title=Heart_rate_3_click&oldid=764"
◾
This page was last modified on 7 September 2016, at 17:53.
◾
Content is available under Creative Commons Attribution unless otherwise noted.
http://docs.mikroe.com/Heart_rate_3_click
9/15/2016
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