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Dragon's breath

Introduction​

Have some IoT fun with your friends. Which of you has the hottest breath, and which the coldest? How you help yourself win is up to you. Anything goes. 😱

In this project, you will learn how to measure temperature with IoT. All you need is the basic HARDWARIO Start Set.

Prepare the box​

  1. Assemble the Start Set and pair it. The Core Module needs the twr-radio-push-button firmware.

  2. In Playground, open the Messages tab. That's where you'll see the temperature changes. The box sends the temperature on its own: regularly every 15 minutes, and straight away whenever it changes by at least 0.2 °C. That's exactly what we'll use.

Messages tab in Playground

Set up Node-RED​

  1. The Messages tab may not be enough for you. ✌️ Build your own colorful temperature gauge from bubbles in Node-RED. First, click the Functions tab in Playground.

  2. Place a light purple node (bubble) called mqtt in on the empty workspace. You'll find it in the network section.

  3. Double-click the node to open it. In the Topic field, you decide what the colorful gauge will show: this time, the temperature. So copy the temperature message from the Messages tab into the field (without the number), or simply use this one:

node/push-button:0/thermometer/0:1/temperature

MQTT topic

Confirm with Done.

  1. Next to the node, place a second one, this time the blue gauge node. You'll find it in the dashboard section. This node decides how the measured temperature appears on screen: as a gauge. Connect the two nodes.

Gauge chart

  1. Double-click the gauge node. In the Type field, you set how the gauge looks (Gauge works best). In the Range field, you set its minimum and maximum value (try 0 and 50).

Node-RED

Confirm with Done. Our tip: You can rename your gauge in the Label field.

  1. Now press the red Deploy button in the top right corner of the screen. 🚨 That starts the whole flow. ❗ Watch out: every time you change the nodes, you have to press Deploy again.

  2. Switch to the Dashboard tab. That's where you'll find your gauge. 😲

Node-RED

Start the game with your friends​

  1. Sit around a table with your friends.

  2. First, find out who's hiding dragon fire inside. 🔥 Take turns breathing on the box. Any help is allowed: try warming up your breath with whatever you have to hand. Try anything and everything. 🙌 ❓ Try it: What warms your breath more, hot tea or chilli peppers?

  3. After the first round comes the frosty round. ❄ Who can cool their breath down to make it the coldest? ❓ Try it: What cools your breath more, an ice cube or minty chewing gum?

  4. Write down the records and try to beat them next time you play.