Watched Pot Never Boils

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  Arduino Code (1 of 2)

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  Arduino Code (2 of 2)

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  NodeMCU Code (1 of 2)

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  NodeMCU Code (2 of 2)

Inspiration

I only have a limited amount of time to make lunch at home between classes and meetings and even then I feel the need to multitask. Any time wasted watching my water boil feels like time that could have been better spent. But as soon as I try to add another task or leave the room I come back to water spilling over the sides of an overboiling pot. I knew there had to be a better way but I couldn't find it. So I built it.

What it does

This program is designed to measure the humidity at a specific distance from a boiling pot of water in order to determine when the water begins to boil. When the pot is boiling, that information will become available on the user's mobile device. Additionally, a fan positioned near the pot will begin to spin. This is to help cool down the surface of the water, ensuring that the water does not boil over the sides of the pot.

Using the arduino with DHT sensor, a measurement is taken at regular intervals to measure the humidity in the area immediately above the water. The code determines if the information is above or below 80%. If the humidity is low, a green light is illuminated and the code continues to take measurements. When the humidity rises above 80%, a signal is sent to a red light as well as a DC motor driving a small fan. The fan then cools the surface of the pot in order to prevent overboiling.

At the same time, a HIGH signal is sent to the nodeMCU indicating that the water has begun to boil. This information is read via a separate code and sends that information to the Blynk app installed on the user's device. The Blynk app shows a binary reading to indicate when the water is or is not boiling.

Challenges we ran into

One challenge encountered was the heat exposure on the humidity sensor. In order to measure a transient change in humidity at the correct time, the sensor had to be placed within a foot of the boiling water, leading to exposure to very high temperatures. In order to overcome this, a towel was wrapped around the sensor in order to protect it and the wires from direct heat while still being close enough to detect the changes in humidity.

What's next for Watched Pot Never Boils

The next step for development would be allowing Blynk to send a push notification to the user in order to alert them that the water is boiling without having to watch the app. Building more robust protection for the DHT sensor would also serve to make the hardware more useful without fear of damaging sensors and wires.

Built With

• arduino
• blynk