Eric Tsai

Minnebar 2019

Mon, 02 Sep 2019 05:18:09 +0000

Session slides.

Idea Costume

Fri, 02 Nov 2018 05:12:53 +0000

Idea Costume

https://youtu.be/as3HVhoIqFU

LoRa-Tooth

Thu, 28 Jun 2018 06:39:32 +0000

Designed BLE sensors and WiFi and LoRa gateways based on Nordic nRF51822 BLE modules and HopeRF’s RFM95W LoRa radios. All wireless data presented as MQTT messages to a central broker, with integration into InfluxDB and Grafana for dashboards. Features include

Distributed WiFi and LoRa gateway architecture
BLE-LoRa bridging
BLE beacon replay/spoof detection
Geolocation of BLE beacons in both WiFi and LoRa architecture
small form factor sensor design for years of battery life on coin cell batteries
Fun development process by using ARM mBED to manage complexity
Low cost, accessible project
Many practical sensor examples

Full project write-up is here.

IoTFuse 2018

Sat, 05 May 2018 07:33:32 +0000

Speaker at IoTFuse 2018 Conference in Minneapolis. Presented platform focused approach to BLE and LoRa device integration using the LoRa-Tooth project.

Slides

BLE Gateway, Node-RED, and ESP8266

Fri, 17 Mar 2017 02:33:29 +0000

This project utilizes a BLE-MQTT gateway to collect bluetooth sensor data and pipe it to perform actions on a wifi connected ESP8266 gingerbread house, as well as utilize Node-RED for additional connectivity (text messages, tweets). The code can be found on my Github.

https://www.youtube.com/watch?v=5QengjRO6EM

Materials

System Diagram

(Inputs) BLE Sensor This is a Bluetooth Low Energy (BLE) module from Silicon Labs (BGM111). I mounted a magnetic reed switch to sense if the door is opened or closed. When there’s door activity, this sensor sends the new door position to the gateway. It’s also used as a water sensor.
(Outputs) ESP8266-Powered Gingerbread House: I’m using an ESP8266 WiFi module to control the gingerbread house LEDs and front door servo motor. The ESP8266 gets door positions and LED colors by subscribing to MQTT topics.
BLE-MQTT Gateway: A BLE module to capture the sensor data and a Raspberry Pi to publish the sensor data to MQTT.

Diagram

Node-RED Flow

Mailbox Notifier

Tue, 07 Feb 2017 08:21:10 +0000

This smart mailbox sensor prototype was contract work for a client.

Explored sensor options and demonstrated feasibility
Circuit design for initial prototype
Firmware development
Webapp prototype

The logo, image, and video below are copyright of George Gruber.

PDF Brochure

IoT Hack Day 2016

Thu, 27 Oct 2016 05:44:04 +0000

I created a BLE-MQTT bridge for the Hackday project, and my team showed a fun example of how it can be used for home automation. The BLE sensors used Silicon Labs BGM111 to sense when windows and doors are opened. The module controlling the mini house was an ESP8266 connected via MQTT. Jake Scearcy built the mobile app using NativeScript, and Vu Nguyen did the 3D printed design for the house. Here’s the Project Page. Our project was voted first place.

IoTFuse 2016

Sun, 24 Apr 2016 18:07:21 +0000

Speaker at IoTFuse 2016 Conference in Minneapolis. Presented live demos of Bluetooth pregnancy test and connected kitchen scale.

Bluetooth Pregnancy Test

Mon, 04 Jan 2016 21:38:14 +0000

Created a functional Bluetooth LE pregnancy test that shares test results on social media. Here’s the project blog.

IoT Hack Day 2015

Fri, 23 Oct 2015 02:12:48 +0000

Captained a team for the Twin Cities IoTHackday 2015. We added wireless connectivity to a toddler toy to make it more educational, fun, and functional. Our project placed 2nd in the competition. The electronics and wireless communication used Light Blue Bean and Photon. We used Node-RED for the Bluetooth communications. The backend game logic was handled by OpenHAB. For the frontend, we used Angular and Material.

My awesome teammates were Chris Larson, Jacob Scearcy, and Kelly Johnson. It was super fun working with them on Go Go Gadget.

System Diagram