Introduction
Aims
In this part of the activity we will:
- Transmit our recorded voltage as a radio signal using the micro:bit
- Receive our radio signal using a seperate micro:bit
- Plot that value on the computer
Learning outcomes
| Learning outcome | |
|---|---|
| Code | Understand the power of built in code features and libraries |
| Radio waves | Understand how these are transmitted and received |
| Visualisation | How to visualise a value on a computer and export a data series |
Preperation
Equipment required
| Equipment item | Quantity |
|---|---|
| Custom wind turbine kit (you just assembled it!) | 1 |
| Extra micro:bit | 1 |
Tools required
| Tool | Quantity |
|---|---|
| Laptop/PC | 1 |
Transmitting the measured voltage as a radio signal
Using two microbits
We will be using two microbits.
- Micro:bit A will send a radio signal (with the voltage measurement). It is attached to the wind turbine.
- Micro:bit B will receive a radio signal (with the voltage measurement). It is attached to your computer.
The radio signal can be transmitted up to 70 meters.
Programming Micro:bit A
🐘 Reminder: Micro:bit A will send a radio signal (with the voltage measurement). It is attached to the wind turbine.
Go to micro:bit make code and start a new program
Enter this code. You will need to use:
- Pins
- Variables
- Serial
- Radio
⚠️ Pick your own radio group from 0-255. Both micro:bits need to use the same group. It must not be the same as anyone else’s in the room.
Download it to your microbit
You will need to:
- Insert your usb lead
- Connect your device (as shown in the image below)
Run the program
You should see:
- A big square shown on the microbit display
You can now unplug the micro:bit from the usb lead.
Connect the battery to the micro:bit. It should show the same image on its display without being connected to the computer
📡 You’re now continuously transmitting the voltage value as a radio signal!
Receiving the measured voltage as a radio signal
Programming Micro:bit B
🐘 Reminder: Micro:bit B will receive a radio signal (with the voltage measurement). It is attached to your computer.
Go to micro:bit make code and start a new program
Enter this code. You will need to use:
- Serial
- Radio
⚠️ Use the same radio group as for Micro:bit A
Download it to your microbit
You will need to:
- Insert your usb lead
- Connect your device (as shown in the image below)
Run the program
Go to show data - device
You should see:
- A small square shown on the microbit display
- When you rotate the shaft of the wind turbine clockwise, then Micro:bit A reads the analogue input and transmits it to Micro:bit B as a radio signal
- Micro:bit B transmits this as serial data (along the usb cable) to the computer
🎉 You’re now continuously transmitting and receiving the voltage value as a radio signal!
Test it with the wind turbine blades
Next steps:
- Install the wind turbine flat blades
- Hold the wind turbine in front of a fan
- Check the voltage value is plotted on a computer when the wind turbine turns