SENSOR-PUCK Silicon Labs

Sensor Puck SENSOR PUCK USERS 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 Figure 1. Silicon Labs Sensor Puck 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 Not Recommended for New DesignsSensor 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 should 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. 2 Rev. 1.0 Not Recommended for New Designs