Silicon Laboratories Biometric EXP EVB UG User manual

Rev. 0.1 8/14 Copyright © 2014 by Silicon Laboratories Biometric EXP EVB UG
Biometric EXP EVB UG
BIOMETRIC EXP Evaluation Board USER’SGUIDE
1. Introduction
The Silicon Laboratories’ Biometric-EXP Evaluation Board is a hardware plugin card for EFM32™ Starter Kits
(STK’s). The Biometric-EXP is intended to demonstrate and evaluate the biometric applications of Silicon
Laboratories Si7013 Humidity and Temperature Sensor and the Si1146 Proximity/UV/Ambient Light Sensor which
is capable of monitoring pulse rate and oxygen saturation (SpO2). A Biometric-EXP Software Demo is available to
download to an EFM32 Wonder Gecko STK through Simplicity Studio. The software is capable of displaying
humidity, temperature, UV, pulse rate, and SpO2 readings on the Wonder Gecko STK display. In addition to the
Silicon Labs sensors, it is also of note that the Biometric-EXP EVB contains a Silicon Laboratories’ TS3310 Boost
DC-DC Converter.
Figure 1. EFM32 Wonder Gecko STK (Left) Connected to a Biometric-EXP (Right)
1.1. Key Features
Si7013 Humidity and Temperature Sensor
Si1146 Proximity/UV/Ambient Light Sensor capable of monitoring Pulse Rate and SpO2
6-pin ribbon cable connector for attaching a wrist-based heart rate monitor EVB (ordered separately as
HRM-GGG-PS)
20-pin expansion header
Battery operated with low power optimizations for long battery life
Demonstration software source code available
USB debug mode allowing HRM and SpO2 samples to be transferred to a PC
Windows GUI to visualize pulse signals and to record samples from USB debug mode
Easy use through Simplicity Studio

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2. Loading the Demo onto the Wonder Gecko STK
The following steps will load the demo firmware onto the Wonder Gecko STK. This process requires Simplicity
Studio which is available for download at www.silabs.com/simplicity-studio.
1. Connect the Wonder Gecko STK to the PC via USB.
2. Launch Simplicity Studio.
Figure 2. Simplicity Studio
3. Open the Simplicity IDE
Figure 3. Simplicity IDE
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4. FromtheSimplicityIDEtoolbaropentheflashprogrammer(icon).
Figure 4. Flash Programmer Dialog
5. Ensure that the Wonder Gecko STK appears in the Device description at the top of the Flash Programmer
dialog.
6. Browse to the hex file EFM32WG_Biometric_EXP_Demo.hex then click Program.
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3. Running the Demo
A Silicon Labs EFM32 Wonder Gecko Starter Kit (EFM32WG-STK3800) and a Silicon Labs Biometric-EXP (see
Figure 1) is needed to run the Biometric EXP Demo.
The Biometric-EXP demo application uses the Wonder-Gecko STK’s LCD to display sensor output and the two
push buttons, PB0 and PB1, to cycle through the modes of the demo. The full operation including startup is
illustrated in Figures 5 and 6.
3.1. Demo Startup
Upon reset, the demo will first check whether PB0 is pressed then store the result. It will then search for a
supported device on the 6-pin ribbon cable connector. If a HRM-GGG-PS, Si1143-M01-PS or Si1147-M01-PS is
detected, the demo will automatically use that device for HRM measurements. In this case, the Si1146 sensor
onboard the Biometric-EXP will not be utilized. SpO2 is not available with either the HRM-GGG-PS or the Si114x-
M01-PS EVB's.
Following the search for a ribbon cable device, the demo will check the stored value of PB0 to enable or disable the
USB debug mode accordingly and display an USB On or USB Off message for 1 second. Refer to “4. USB Debug
Mode” for details on USB debug mode. Lastly, the demo will display version information then start the demo in
Heart Rate Monitor mode.

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Figure 5. Biometric-EXP Demo Startup Sequence
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Figure 6. Biometric-EXP Demo Modes
*Note: SpO2 Monitor mode is not available when using a HRM-GGG-PS, Si1143-M01-PS or Si1147-M01-PS.
3.2. Heart Rate Monitor Mode
When heart rate monitor demo is idle, the LCD will show the word “Pulse” followed by a message instructing the
user to place his/her finger on the optical sensor. In idle mode, the sensor is not continuously sampling. Rather, it
executes one sample every two seconds by performing a forced measurement. That sample is then analyzed to
determine if there is skin contact with the sensor. Only when the application detects skin contact does it begin
sampling continuously and running the HRM algorithm. It will remain in run mode (continuous sampling) until skin
contact is removed for greater than two seconds. This approach significantly reduces power usage when idle.
When the application is acquiring the heart rate, it will display the word “Wait” on the LCD. It typically takes five to
seven seconds to acquire a valid heart rate. Once a valid heart rate is measured, the display will show the heart
rate. If the heart rate is not displayed within seven seconds, it is likely that the algorithm cannot get a valid pulse
rate. When this occurs, the user should remove his/her finger and try it again adjusting the position of the finger
and the finger pressure as needed.
Proper finger position in relation to the sensor and LEDs as well as proper finger pressure is essential for accurate
measurements. The finger should fully cover both LEDs and the sensor. Proper finger position is illustrated in
Figure 7.
Figure 7. Proper Finger Placement
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3.3. SpO2 Monitor Mode
When SpO2 mode is active, the LCD will show “SpO2” followed by a message instructing the user to place his/her
finger on the optical sensor. Beyond that, SpO2 monitor mode mirrors the operation of the Heart Rate Monitor
mode as described in “3.2. Heart Rate Monitor Mode” . Please note that SpO2 mode is not available when using a
HRM-GGG-PS, Si1143-M01-PS, or Si1147-M01-PS device via the 6-pin ribbon cable. Even more so than HRM,
proper finger position and pressure is important to achieve a good SpO2 measurement. Refer to Figure 7 for an
illustration of proper finger position.
3.4. Ultraviolet Sensor Mode
When the UV sensor mode is active, the LCD will show “UV” followed by the measured UV index. In this mode, the
UV reading is updated every two seconds.
3.5. Temperature Sensor Mode
In the temperature sensor modes, the LCD will show the temperature in Fahrenheit or Celcius as indicated by an
“F” or a “C” following the reading. In this mode the temperature reading is updated every two seconds.
3.6. Relative Humidity Sensor Mode
In the relative humidity sensor mode, the LCD will show “RH” followed by the relative humidity reading. In this
modem, the relative humidity reading is updated every two seconds.

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4. USB Debug Mode
The Biometric-EXP demo firmware includes a debug mode that enables Heart Rate Monitor and SpO2 raw
samples from the sensor to be streamed to a host PC via the Wonder Gecko STK’s USB interface. Only HRM and
SpO2 data is available via the USB debug interface. UV, Relative Humidity, and Temperature data is not available.
4.1. Enabling USB Debug Mode
In order to maintain power efficiency of the demo, the USB debug mode is disabled by default. The LCD will show
“USB OFF” during startup. To enable USB debug mode, the user must hold down button PB0 then press and
release the Reset button. Both buttons are on the Wonder Gecko STK as shown in Figure 19. The user should hold
down PB0 until the LCD shows “USB ON.” At this point, USB is enabled and the demo will run normally. To later
disable USB debug mode the user can press the Reset button without holding PB0.
4.2. Connecting to USB Debug Mode on a PC
Prior to using USB debug mode, the user must first install the Biometric-EXP Windows Evaluation Software. This
will install the Windows applications and drivers necessary to use USB debug mode. The Wonder Gecko STK has
two USB type connectors: a USB Mini type connector labeled J-Link on the short side of the EVB and a USB Micro
type connector on the long side of the EVB. Refer to Figure 19 on page 20 for details on the component layout of
the Wonder Gecko STK. The USB Micro connector is used for the USB debug interface. In addition to using the
correct physical interface, the Power Source Select switch must be set to USB (center position) for proper
operation.
USB debug mode utilizes a Virtual COM Port (VCP) interface to communicate between the Biometric-EXP demo
and the PC. With the Windows software installed, USB debug mode enabled on the Wonder Gecko and a USB
cable connecting the Wonder Gecko STK and the PC, the device will appear in Windows Device Manager as a
COM port as shown in Figure 8.

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Figure 8. Biometric-EXP Virtual COM Port Device in Windows Device Manager
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4.3. Windows Applications for USB Debug Mode
The Biometric-EXP Windows Evaluation Software includes two Windows applications for evaluating and
debugging the Biometric-EXP Heart Rate Monitor and SpO2 functions. The Windows Graphical User Interface
(GUI) demo provides a waveform display of the HRM data along with the HRM and SpO2 calculated values. The
GUI demo also allows the user to record the streaming data to a file for further analysis. A screenshot of the GUI
demo is shown in Figure 9.
Figure 9. Windows Graphical User Interface Demo
The Windows Console Demo provides a running, once-per-second text output of many parameters that are used
within the HRM and SpO2 algorithms including the HRM and SpO2 results. This tool can be used for advanced
analysis of the HRM and SpO2 streaming data; however, the details of the parameters and how to use them to
analyze a HRM-SpO2 recording is beyond the scope of this document. Refer to the HRM-SpO2 API Reference
Manual available from Silicon Laboratories for further details. The C++ source code of the Console Demo is
supplied within the installation. A screen shot of the Console demo is show in Figure 10.

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Figure 10. Windows Console Demo
To connect the console to the streaming output from the Biometric-EXP, the user can type –u COMx <filename> at
the prompt. In this command, COMx is the VCP COM port as shown in Figure 8, and the optional input <filename>
specifies the file in which the streaming data is to be stored. Note that if <filename> is not provided, the console
automatically stores the data to a default file. This default file is overwritten each time the demo is run.
The console also has the ability to playback recorded files. This is done by typing –f filename at the prompt. In
this command, filename specifies the source file containing the saved recording.
It is important to note that the USB debug interface is a one-way interface. Therefore, the applications can only
take the streaming data as an input. They do not allow the user to control the Biometric-EXP software.
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5. Importing the Source Code Project into Simplicity Studio
The following steps will import the Biometric-EXP Demo source code into Simplicity Studio resulting in a project
that can be compiled, linked and debugged using the Wonder Gecko starter kit.
Simplicity Studio is available for download at www.silabs.com/simplicity-studio.
Note: In the near future, this software will be integrated into Simplicity Studio making the import task seamless. When the inte-
gration is complete, the procedure below will be obsolete.
1. Store the Biometric-EXP software distribution uncompressed in a folder that is accessible from the PC.
2. Start Simplicity Studio and Open the Simplicity IDE.
Figure 11. Simplicity Studio
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Figure 12. Simplicity IDE
3. In the Simplicity IDE menu select FileImport.
4. Under the General heading, select Existing Projects into the Workspace then click Next.
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Figure 13. Simplicity IDE Import Dialog
5. Select Select root directory then Browse to the folder EFM32WG_Biometric_EXP_Demo in the
Biometric-EXP Demo distribution.
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Figure 14. Select the Project to Import
6. Confirm that the check box for the project is checked.
7. If you wish to make a local copy within the Simplicity IDE workspace select Copy projects into
workspace.
8. Click Finish.
9. The EFM32WG_Biometric_EXP_Demo project is configured to link to a binary library that is stored in a
folder labeled lib in the Simplicity IDE workspace folder. This folder is not generated by the import process
described in the steps above; therefore, the link will be broken.
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Figure 15. Simplicity IDE with EFM32WG_Biometric_EXP_Demo Project
To correct the link:
a. In the Simplicity IDE Project Explorer, right click on the lib folder then select Properties.
b. The Resources page of the Properties dialog displays the link path. Modify this path by clicking the
Edit button then browsing to the location of the lib folder.
Note: Alternatively, you can manually copy the entire lib folder from the distribution to the location specified in step “b”.
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Figure 16. Symbolic Link to the Lib Folder
Upon completion of the steps above you should have a working project in Simplicity Studio that can be built and
debugged.
10. To build the demo, simply click on the icon in the Simplicity IDE. Note that there are two build
configurations: Release and Debug. You can select between the two by clicking the down arrow next to
the Hammer icon.
11. To debug the project, select the Debug build configuration then click on the icon in the Simplicity
IDE. A debug session will automatically launch and if a board is connected, the project will be loaded into
the MCU.
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6. Hardware Overview
6.1. Block Diagram
Figure 17. Biometric-EXP Block Diagram
6.2. Hardware Connectors
As illustrated in Figure 17 there are two separate I2C buses implemented on this board. The Si1146 is on its own
bus while the Si7013 and the I2C Ribbon Connector J6 are on the second bus. This allows for expansion boards
designed for the I2C Ribbon Connector to connect to the Biometric-EXP without the possibility of an I2C slave
address conflict between any potential Si1145/Si1146/Si1147 devices on the expansion board.
Table 1 details the pinouts and signal function of the Biometric-EXP connectors JP3 and JP4.
Table 1. Expansion Connectors (JP3 and JP4)
Pin # Biometric-EXP Signal Description WonderGecko Signal
1GND GND
2 VMCU VMCU
3RedLEDD3 PC0
4NotUsed PD0
5 Green LED D3 PC3
6NotUsed PD1
7 Si7013 and I2C Ribbon Connector (J6) SDA PC4
EXP Connector
(JP3) EXP Connector
(JP4)
TS3310 DC-DC
Boost Converter
Si1146 Proximity/
UV/Ambient Light
Sensor
Si7013 Humidity
& Temperature
Sensor
I2C Ribbon
Connector
(J6)
Red
IR
5V
Vmcu
I2C1
All other lines
I2C2

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Table 2 details the pinouts and signal descriptions of the 6-pin I2C connector J6.
8NotUsed PD2
9 Si7013 and I2C Ribbon Connector (J6) SCL PC5
10 Not Used PD3
11 Not Used PB11
12 Enable TS3310 Boost DC-DC Converter PD4
13 Not Used PB12
14 Si1146 and I2C Ribbon Connector (J6) INT PD5
15 Not Used PC6
16 Si1146 I2C SDA PD6
17 Si1146 I2C SCL PD7
18 Not Used 5V
19 Not Used GND
20 3.3 V 3.3 V
Table 2. 6-Pin I2C Connector (J6)
Pin # Signal Description
1I2CSCL
25V
3I2CSDA
4GND
5INT
6VMCU
Table 1. Expansion Connectors (JP3 and JP4) (Continued)
Pin # Biometric-EXP Signal Description WonderGecko Signal

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6.3. Hardware Component Layout
Figure 18. Biometric-EXP Hardware Component Layout
Figure 19. Wonder Gecko STK Component Layout
Si1146 Proximity/UV/Ambient Light
IR and Red LEDs
EXP connector for
EFM32 STK
Silabs TS3310 DC-DC
Boost Converter
I2C Ribbon Cable
Connector
Si7013 Humidity &
Tem
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