ECG 6 Click

How does it work?

The ECG 6 Click is based on the MAX86150, is a complete electrocardiogram (ECG) from Analog Devices. It is designed for mobile health. The Click board™ has many features to provide health measurements: electrocardiogram, pulse oximetry, and heart rate.  All these features allow ECG 6 Click to be used in a range of health-related ECG, SpO2 subsystem and HR applications including fitness and activity heart rate monitors, portable ECG, wearable and remote health monitors, and similar.

The MAX86150 contain integrated the SpO2 subsystem. The SpO2 subsystem is peripheral capillary oxygen saturation. It is measured by a device called a pulse oximeter. A clip is placed on the finger or foot of the patient and light is sent through the finger and measured on the other side. The MAX86150 integrates red and infrared LED drivers to modulate LED pulses for SpO2 and HR measure­ments. The LED current can be programmed from 0mA to 100mA with proper VLED supply voltage. The LED pulse width can be programmed from 50μs to 400μs to optimize accuracy of results and power consumption based on use cases.

ECG 6 Click allows several types of electrodes to be used. It supports both stainless-steel and silver-chloride electrode types. The electrodes are used to perform differential measurement of the voltage generated by the heart. Therefore, the heart can be monitored from a single plane only - the coronal plane. However, this is quite enough for the fitness, heart rate monitoring and similar applications.

The extensive interrupt engine can be used to trigger the host MCU from various sources, including interrupt events due to lead detection, R-R detection, fast-recovery event, FIFO buffer states, and many more. These interrupt sources can be utilized to trigger a state change on the interrupt pin (INT) of the MAX86150 IC. This pin is active-low.

The voltage level of the logic section can be selected via VCC SEL jumper, between 3.3V and 5V. This allows for both 3.3V and 5V capable MCUs to use the SPI communication lines properly.

Specifications

Pinout diagram

This table shows how the pinout on ECG 6 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	NC
	NC	2	RST	INT	15	INT	Interrupt OUT
	NC	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	SCL	I2C Clock
	NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	5V	Power supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Software Support

We provide a library for the ECG 6 Click on our LibStock page, as well as a demo application (example), developed using MIKROE compilers. The demo can run on all the main MIKROE development boards.

Library Description

The library provides the user with measurements from ECG sensors and PPG sensors. The user has full control of module settings and reads all registers via I2C communication.

Key functions:

• void ecg6_get_sample_data( ecg6_element_t *element, uint8_t num_sample ) - Get one sample from FIFO
• uint8_t ecg6_ppg_default_config ( ) - Default configuration for PPG sensor
• uint8_t ecg6_ecg_default_config ( ) - Default configuration for ECG sensor

Examples description

The application is composed of three sections :

• System Initialization - Initialize I2C module and all necessary pins
• Application Initialization - Checking communication accuracy and running default configuration for measurement
• Application Task - Measures an ECG signal or PPG sensor and draws a graph on a SerialPlot

void application_task ( )
{
    ecg6_element_t sample;
    ecg6_get_sample_data( &sample, 0x00 );

    if ( DEMO_EXAMPLE == ECG_EXAMPLE )
    {
        plot_ecg_data( sample.element_1 );
    }
    else
    {
        plot_ppg_data( sample.element_1, sample.element_2 );
    }
}

Additional Functions :

• plot_ecg_data ( ) - Sends ECG sensor data to SerialPlot
• plot_ppg_data ( ) - Sends PPG sensor data to SerialPlot

Note: When using ECG measurement - PPG measurement must be switched off ... Drawing speeds vary for PPG and ECG sensor.

The full application code, and ready to use projects can be found on our LibStock page.

Other MIKROE Libraries used in the example:

• I2C Librar
• Conversions Library
• String Library
• UART Library

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. The terminal available in all MIKROE compilers, or any other terminal application of your choice, can be used to read the message.

mikroSDK

This Click board™ is supported with mikroSDK - MIKROE Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.