Adrian Lita

What I Did

• Schematic
• Firmware
• Backend

Overview

SAMB was one of the biggest and most challenging projects I've worked on. It was spanned over an 18-month period, with 5 iterations before being finished. It envolved a team of 4 (myself, the client, a PCB designer and a mechanical designer). The purpose was to build a smart braclet for elderly people, battery-powered with a battery span of 1 month. The end result was just that! The braclet was intended to be used in care houses, as well as for selling to individual customers. Besides the bracelet, I've also built a Raspberry Pi-based basestation which was able to connect to multiple (128) bracelets via BLE.

Purpose - bracelet

• Fall detection (it involved an accelerometer and a barometer)
• BLE operation while in range of a basestation; multiple basestations could cover a large area. In this mode, the bracelet's battery would last over a month
• GSM + GPS operation if the basestation was not available (ie: the person left the house)
• Buzzer motor + RGB led used for alerts (pill-alert)
• Heartrate sensor
• Two buttons - top one to trigger an alarm, and side-button for acknowledging alerts or cancel alarms
• Battery charger

Purpose - basestation

• Relay between the cloud and the braclet
• Secure communication between bracelet and basestation (proprietary)
• SSL between basestation and cloud
• Multiple basestations across a large area, like a care house or hospital

Purpose - Backend

• manage bracelets (individually or per care-house)
• GPS tracking on a map when necessary

Technologies Used

• C - bracelet
• Python - basestation
• PHP - backend
• BLE, GSM, GPS
• HR sensor, accelerometer, barometer