You can already work with micro:bit sensors and simple programs. Today you will build a Seismic and Meteorological Station: one micro:bit reads temperature, light and shake, and three others show that data.

Before you run anything, what do you think will appear on the temperature board when the station warms up or cools down?

Open the project you saved earlier. You will predict, build, run and fix step by step at your device.

Your weather and earthquake station is four micro:bits doing four jobs, talking to each other over radio:

1. The station reads temperature, light and shake, and sends those readings out.
2. The temperature display shows what it receives.
3. The day/night indicator shows light or dark.
4. The seismic alert stays quiet until it hears a shake.

Code and test one micro:bit at a time. Later you will log the readings over time so you can look at them after the event, not only as it happens.

Let's start with the 'Seismic and Meteorological Station' micro:bit. This micro:bit will gather and broadcast the sensor data. It will monitor temperature, light levels, and 'seismic' activity (which we simulate by shaking the micro:bit).

Add the following code:

radio.setGroup(1)

basic.forever(function () {
    radio.sendValue("temperature", input.temperature())
    radio.sendValue("lightlevel", input.lightLevel())
})

input.onGesture(Gesture.Shake, function () {
	radio.sendValue("seismicactivity", 1)
})

In the code above, we're setting up the radio communication in group 1. We're also setting up an event handler for the 'shake' gesture to send a 'seismicactivity' message. In the forever loop, the micro:bit constantly sends the temperature and light level values.

Once you have added the code, download it onto the micro:bit that will act as the 'Seismic and Meteorological Station'.

Next create a new micro:bit project and call it something like 'Temperature Display'. This will be the project for the 'Temperature Display' micro:bit. This micro:bit will listen for the 'temperature' radio messages and display the received value on its LED matrix.

Add the following code:

{radio.setGroup(1)
radio.onReceivedValue(function (name, value) {
    if (name == "temperature") {
        basic.showNumber(value)
    }
})}

In the code above, we're setting up the radio communication in group 1 and listening for 'temperature' messages. When such a message is received, the micro:bit displays the temperature value.

Once you have added the code, download it onto the micro:bit that will act as the 'Temperature Display'.