Develop a smart thermometer that can be used over a wide variety of applications.
- Large easy to read display.
- Environmentally friendly (no throw away batteries).
- A product that does not become obsolete tomorrow.
- High accuracy over full temperature range.
- Extremely easy to use.
Everything Has a Temperature
Everything from candy to exhaust manifolds has a temperature. It's time to check the temperature and you grab the inexpensive thermometer you purchased, press the on button and nothing happens because the little coin cell ran out of energy. Then, you find the replacement battery costs about as much as the original device. The throw away cycle repeats itself.
We have all purchased multiple chargers and product specific interface cables for our cell phones and now tablet based devices. The only common interface left on these devices seems to be the 3.5mm headphone jack. This isn't the easiest interface to use but we took the challenge and figured out how to use it for our application. The smart thermometer harvests energy from the headphone jack and uses the microphone input to transmit data back to the iOS or Android device. No batteries are required and we don't see the headphone jack interface going away anytime soon. Our vision can now become a reality with your help.
- Temperature Range = -30°C to +250°C (-22°F to +482°F)
- RTD Sensing Element
- Accuracy = ±1.05°C over temp range
- High Temperature Plastic Body
- Stainless Steel Probe Assembly (food grade)
- Works with majority of iOS & Android devices
- PSoC® Enabled (read technical details below)
We chose a high end programmable system on a chip for the electronics. This approach yields a very efficient product development cycle and also allows us to quickly make hardware changes to our product without having to redesign the entire circuit board. Having programmable hardware is awesome! For those who want more specifics we chose a Cypress PSoC® device. This approach gives us a high level of confidence in delivering a product on-time. It also gave us the ability to do some pretty complicated analog and digital circuits all on a single IC. Thanks to the low power capabilities of this technology, using the Smart Thermometer will not be a large power drain on your device battery as it operates on just a few milliwatts of power.
Product Development Process
The first step was to specify what it was we wanted to design. This is always an iterative process and we continue to update our specifications as we continue to follow through on our product design. It was especially important to have a specification in place for our app developer to follow to make sure the app met our expectations. This paid off as our app developer did a very good job on gettting the initial app to work as we expected. It is very simple at this point but proves out what we need for now. Once the project is funded we will be able to take our app to the finish line. The feature set may grow if funding allows. We are always open for ideas from the kickstarter community too.
The second step was to figure out how to harvest energy from the headphone jack (audio signals) in order to power the Smart Thermometer. There are some interesting resources on the internet where others have done this but most yielded poor results. Dan's experience in pro audio and power electronics became very beneficial here. In the end, we have found a way to generate as much as 100 milliwatts of power from this interface. We only need about 1/10th or less of this amount of power to run the Smart Thermometer. This enabled the project to move forward and we considered it a milestone to the success.
The third step involved a multitude of parallel activities. Phil was now able to go to town on the mechanical designs as we knew the rest of the electronics was fairly straightforward to implement. We went through about 3 rounds of concept designs until we finally settled on what you have seen in our video. The prototypes seen in the video were created with 3D printing technology by a local company that both Phil and Dan have done extensive work with in the past. It all came together around Thanksgiving and we were delighted to start producing our video.
A sudden sensor change........
During the filming for our kickstarter video, we realized we had missed something in our original specs. Phil's wife is quite good at candies and baking and she informed us the Smart Thermometer needed to be extremely accurate for these applications. The original sensing element was based around a thermistor design that was quite accurate from 0 to 100 degrees celcius but slowly lost accuracy the closer it got to 250 celcius. In the end it would have met the majority of applications out there but we would have had some unhappy candy makers. So, we decided to switch to a RTD sensing element which costs more but produces very good results over the entire temperature range. We believe candy makers will be very happy we made the change.
The fourth step is going from prototype to production. This is where we need the funding to move forward. Going from idea to prototype is a big step but equally important is having the know how to take the product into production. This is where our experience will pay off. We have detailed our manufacturing plan in the risks and challenges section below.
Risks and challenges
We have designed and developed the Smart Thermometer, but we need your help to push it into production. We cannot build high quantities of the Smart Thermometer on our own, so we have teamed up with several US based component manufacturers to bring you a high quality product. During our development process we have had the privilege of working with several sources for all of our components. If the Smart Thermometer project funds, we are prepared to kick off our vendors immediately. First, we will initiate tooling and begin to inventory parts for final assembly. Next, we will perform an engineering build of 10 units with a local contract manufacturer to validate our work instructions and assembly process. Then we will perform a pre-production build of 250 units (at 50 units per day) in order to evaluate the production line and finalize all remaining process flow parameters. After we complete our pre-production run, the Smart Thermometer will go into full production right here in Arizona.
Tooling is always a challenge but even more so when dealing with high temperature plastics. Injection molding tools and processes become more expensive and complicated to run. This is one of the major drivers for the amount of funding we need. We have selected Stanyl®, a high temperature plastic, and will be using a local company with experience running this material. Once the funding is in place this will be a major focal point to ensure the success of our project.
Developing the app to work on two platforms requires more work and increases our funding requirements. We have contracted with a seasoned app developer that is accustomed to both iOS and Android platforms and has successfully launched apps in both environments.
We will not be successful without you. We think the product is hot (pun intended) but it needs a cool kickstart to make it happen! Thanks again for your support!Learn about accountability on Kickstarter
- (31 days)