Silicon Laboratories SENSOR PUCK User Manual

Sensor Puck

SENSOR PUCK USER’S GUIDE

1. Introduction

The sensor puck demonstrates Silicon Laboratories optical sensor (Si1147-M01) RH and temperature sensor
(Si7021) and low power MCU (EFM32G210 “Gecko”). The data is broadcast using a Bluetooth Low Energy (BLE)
module and can be displayed on a mobile device (Apple iOS or Android) that supports the BLE protocol.

By using broadcast mode, a connection does not have to be established, making it possible to display the data
from several modules at the same time.

2. Evaluation Kit Description

The evaluation kit consists of a sensor puck with a battery and the on/off switch in the off position. Install the battery
if it is not installed. The + terminal of the battery faces away from the board towards the + terminal of the battery
holder. Remove the pull tab separating the battery from the battery holder if needed. When the switch is turned on,
the puck will automatically start taking and broadcasting data. For the puck itself, there is no installation required.

Rev. 1.0 2/15 Copyright © 2015 by Silicon Laboratories Sensor Puck

Figure 1. Silicon Labs Sensor Puck

Sensor Puck

The data that is broadcast is generally displayed on a mobile device. To display the data the Silicon Labs Sensor
Puck app must be installed on the mobile device. The application is available for no charge from the Apple App
Store or the Google Play Store. (Search for Silicon Labs Sensor Puck.)

3. Operation

 Environmental mode

Measures ambient light, UV index, ambient temperature, and ambient humidity.
This is the default mode of operation and the lowest power.
In this mode of operation measurements are taken and broadcast (once per second).
The LED flashes green once per measurement cycle.
The battery current consumption in this mode is approximately 1.5 mA average, which means that a standard CR2032

battery will last about five days. The battery for this demo is not rechargeable so it must be replaced if it is depleted.

 Biometric mode

At the once per second interval for environmental monitoring, the puck checks for the presence of an object over the

Si1147-M01 (under the acrylic cover).

If an object is detected the puck will go into biometric mode and attempt to measure heart rate.
Heart rate is measured by the reflection of IR light from an LED inside the Si1147-M01.
The light is reflected from a finger-tip to measure the heart rate.
In biometric mode the power consumption goes up to 7 mA, so battery life will decrease to about one day in this mode.
In biometric mode, the LED will flash red while it is acquiring the heartbeat and then switches to continuous green once

the heartbeat has been acquired.

To avoid excessive power drain in case the puck is left on and covered with an object, the puck will exit biometric mode

after 90 seconds. In this case, the object must be removed and a finger sho uld be placed over the acrylic cover to start
biometric monitoring again.

The data from the puck is broadcast over a BLE “advertisement” packet. The mobile device that displays the data does

not need to make a connection to the puck. For this reason, it possible that a single mobile device (i.e. a phone) can
display data from multiple pucks.

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Sensor Puck

4. Sensor Puck Applications

There is a Sensor Puck app for iOS devices and another Sensor Puck app for Android devices. Both apps are
named “Silicon Labs Sensor Puck”.

The iOS Sensor Puck app can be installed from the Apple App Store. The iOS app runs on devices with iOS 7 and
higher, and has Bluetooth 4.0 hardware. Silicon Labs has verified that the iOS app runs on iPhone 4S, 5, 5S, 6 and
6 Plus. The iOS app also runs on iPad 3 and 4.

The Android Sensor Puck app can be installed from the Google Play Store. The Android app runs on devices with
Android version 4.3 and higher, and has Bluetooth 4.0 hardware. Silicon Labs has verified that the Android app
runs on the following devices: Samsung Galaxy S4, Samsung Galasy S5, Samsung Galaxy Tab 3, Motorola
Moto E, Motorola Moto G, HTC Desire, HTC One Max, LG Nexus 5, LG G Flex, Sony Z1, Sony T2 Ultra, and Asus
Nexus 7.

When the puck is in environmental mode, the Silicon Labs Sensor Puck app displays the environmental screen:

Figure 2. Android Environmental Screen

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Sensor Puck

The environmental screen displays the environmental sensor measurements and the battery status. The puck
name is displayed at the top of the screen. The temperature scale can be changed between Celsius and
Fahrenheit by tapping the small C and F buttons.

When the puck is in biometric mode, the Android Sensor Puck displa ys th e bio m et ric scr een .

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Figure 3. Android Biometric Screen

Sensor Puck

The iOS Sensor Puck app does not have a biometric screen. The iOS app displays the heart rate in the lower right
corner of the environmental screen:

Figure 4. iOS Environmental Screen

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