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TempSensor and CloudConnector

Key technologies: 802.15.4, Cloud Services, TCP/IP, C, FreeRTOS, MySQL, HTML, CSS

In 2012, I started talking to my dad and brother about possible product ideas. We discussed several options, but eventually landed on a cloud-connected system of sensors. We thought that sensors and devices would soon be connected to the internet, and we wanted to be one of the people that helped make this happen. Our first sensor would be a residential temperature sensor.

Our plan was to start with two devices: an internet-connected 802.15.4-to-Ethernet router and a 802.15.4 sensor. The router would send data to our webserver (this strategy prevented any issues due to firewalls). The 802.15.4 sensors would eventually be mesh-networked and would send their data to the internet through the router.

I took on the design of the CloudConnector router device. We chose to use a simple microcontroller in order to save cost. It would be very simple; it would grab packets and forward them to the server. It was built using an Atmel Cortex-M3 SAM3X processor. It had an Ethernet port, an 802.15.4 antenna, a few LEDs, and a reset pushbutton.

My dad and brother worked designed and built the TempSensor. It had an on-board thermistor, a coin-cell battery, and an Atmel ATMEGA128RFA1 (combination microcontroller and 802.15.4 radio). It was designed to be ultra low-power.

I also designed the cloud backend service called “CloudHandler.” The CloudConnector connected to the CloudHandler service via TCP port 6201 and pushed the temperature sensor measurements. The CloudHandler service stored the messages into a MySQL database.

My website had a page to display the temperature sensor measurements. After everything was installed and working, you could visit our website to see the temperature in Platteville, WI, La Crosse, WI, and Minneapolis, MN.

Eventually, we decided that consumers wouldn’t be interested in these wireless temperature sensors at the price point that we could hit. Without a different set of features, there wasn’t enough incentive to buy the temperature sensors from us when there are very cheap wireless temperature sensors available from China.

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