IoT game for the whole class: Measure the temperature in your school

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IoT game for the whole class: Measure the temperature in your school


This project will reveal all the secrets of your school, whether someone hunts ghosts or just wants to find a hot place for their next date. Measure the temperature at different spots of your school with your classmates and try to be the one to discover the biggest extreme. 😱

With this project you will learn to measure temperature with IoT and display it on your mobile. All you need is the basic Big Clown kit, the Starter Kit.

Suggest the game to a physics teacher to add some excitement to the lesson or go for it with your friends after school.

This game is all about winning. Who finds the coolest or hottest place in school is the king! 👑 If there are several boxes in your class, either work individually or in small groups. If you have only one, take turns.

Get your box ready

  1. Put together the Starter Kit and pair it: if you are doing it for the first time, we have prepared a simple guide here. For the Core Module, you need the radio push button firmware. If you don’t know how to download the firmware or what it is, you will find out here.
  2. You can see the temperature changes in the Messages tab in the Playground.
MQTT messages in HARDWARIO Playground

Set up the Node-RED

  1. Set your own indicator to record the lowest or highest temperature. On your computer, start with the bubbles in the Node-RED. First, click on the Functions tab in the Playground.
  2. Place the light purple node (a bubble) named MQTT in the empty desktop. You can find the node in the Input section.
  3. Double-click on the node to open it. In the Topic line you will specify what you want the colour indicator to display. Now it will be temperature. Therefore, copy the message with temperature from the Messages tab (without a number) into the field. Or just use this one:
MQTT input topic

Confirm it with the Done button.

Get the app started on your mobile

  1. The box connects to your smartphone thanks to the Blynk app. 📱 Find out how to deal with Blynk.
  2. Select Gauge (indicator) from the menu. So far, it looks like this:
Blynk - gauge
  1. Double-click on the gauge. It will open its settings. Tap on the PIN button.
Blynk - set virtual pin
  1. The PIN setup will open. Select Virtual and choose any number you want on the right. Remember it for later.
Blynk - set virtual pin

Confirm it with the OK button.

  1. Besides the PIN button, set from how many degrees to how many degrees the chart will show the temperature. Make it generous, for example, try -30 to 45 °C. In the line below next to the text, type the /pin/ unit, which will show after measurement: °C.
Blynk - set range of values
  1. Go back to the chart with the arrow and just click the Play triangle in the upper right corner.

Connect your mobile with the box

  1. Go back to your computer. In the Node-RED, add the dark green Write node behind both nodes. You can find it on the left, under the Blynk ws section.
Node-RED Blynk write
  1. Open the node by double-clicking. You’ll see a small pencil on the right. Click on it and a new window will open. In the Auth Token field, copy the token you have sent to your email. Into the URL field, copy the Blynk Cloud Server from the bottom window: ws://

Confirm the setting with the Add button. But don’t leave the node just yet. 👈

  1. In the Virtual Pin line, write the number you chose as a PIN in Blynk. Do not use the letter “V”.
Node-RED Blynk set pin

Confirm it with the Done button.

  1. Now connect both nodes and click on the red Deploy button at the top right. 🚨
Connect Blynk

One-up your class

  1. Alone or in a group, guess which place might be the hottest or coolest at school.🔥 ⛄
  2. Each individual or a group has only 15 minutes to explore. 🔦 Let’s make it exciting.
  3. Take the box to the spot and watch the temperature on your mobile. It may take some time for the temperature to show in the gauge.
measure temperature and show in Blynk
  1. Try several places and in the end, call the most extreme results. Congrats to the winners! 🎇