What is an actuator?

In control systems, actuators are devices that convert control signals into physical action. 

They take the output of the controller or processor (usually electrical signals) and produce mechanical movement or some other form of physical effect. E.g. Turn on a motor.

Project - micro:bit Motor Control

R1,2 & 3

Click this link for an introduction to the basics

The 3 volt output from the micro:bit is not enough to power most electric motors used in STE(A)M projects. These typicall require 6 volts or more. 

To control the additional voltage a breakout or expansion board (an additional circuit board) is required. 

You will also need a 6 volt battery pack to power the breakout board and micro:bit.

Kitronik has created breakout boards specifically for the microbit.

Code block extensions have been added to MakeCode to make programming them  an extremely simple activity for children as young as 8 years old.

To find out more about Kitronik robotics and STEM projects, follow this link

The MakeCode editor has a Kitronic motor board extensions with pre-designed blocks for controlling the outputs from the robotics board.

Click this link for an introduction to the basics

Project - Buggy Control

R1, 2, 5 & 7

micro:bit coding

Motor control - moving forwards

• In the list of code blocks, click on + Extensions

• Find kitronic-motor-driver and select it

• This will add motor driver options to your list of blocks

• Create an on button A pressed block with the code to make both motor 1 AND motor 2 to come on forwards with a speed of 40

• Create an on button B pressed block with the code to turn both motors off

Develop the code - move in a square

• Create code to make the vehicle turn through 90 degrees.

• Create code to move the vehicle round in a square using a repeat 4 times loop.

First step is to create an algorithm for the challenge and then turn it into code.

Algorithm:

Start

Repeat 4 times

Motor 1  on forwards

Motor 2 on forwards 

Pause 3000

Motor 1  on forwards 

Motor 2 on reverse 

Pause 500

Refine the code

Problem 1 - buggy does not run straight.

Solution - adjust the motor power to one of the motors to correct this.

Problem 2 - Buggy does not turn exactly 90 degress.

Solution - adjust the length of the second pause to correct this.

Problem 3 - Buggy does not stop.

Solution - add code to turn both motors off at the end.

Project - Build your own buggy

R2, 3 & 5

Resources needed:

• two 200:1 ratio, 6 volt electric motors

• Kitronik robotics board

• 6 volt battery pack (x4 AA 1.5 volt cells)

• micro:bit

• plywood or cardboard

• small plastic, wood or metal ball

• 2 wheels cut from plywood or cardboard or 3D printed

• small box or container made from cardboard or 3D printed

• glue, tape or hot glue gun

Approximate cost of components, UK£24 

Follow the instructions in the video below.

Internet of Things

R1, 2 & 4

Billions of electronic digital devices are connected by wires or wirelessly to the internet. 

Collectively, these devices are known as the internet of things or IoT for short.

Just like your phone connects to the internet, other “smart things” can do that too — and they can share information or even make decisions automatically.

We are living in an increasingly connected world and all of the devices listed below and be thought of as 'robots' in that they work autonomously.

Smart Home

Smart Thermostat (e.g., Nest, Ecobee)
Smart Light Bulbs (e.g., Philips Hue)
Smart Door Locks (e.g., August, Yale)
Smart Doorbells (e.g., Ring, Nest Hello)
Smart Plugs (e.g., TP-Link Kasa)
Smart Security Cameras (e.g., Arlo, Blink)
Smart Smoke Detectors (e.g., Nest Protect)
Smart Refrigerators (e.g., Samsung Family Hub)
Smart Ovens (e.g., June Oven)
Voice Assistants (e.g., Amazon Echo, Google Nest)

Wearables

Smartwatches (e.g., Apple Watch, Fitbit)
Fitness Trackers (e.g., Garmin, Xiaomi Mi Band)
Smart Glasses (e.g., Ray-Ban Meta, Vuzix Blade)
Smart Rings (e.g., Oura Ring)
Smart Clothing (e.g., Levi's Commuter Trucker Jacket with Jacquard)

Healthcare & Medical

Connected Glucose Monitors
Smart Blood Pressure Monitors
Wearable ECG Monitors (e.g., KardiaMobile)
Smart Inhalers
Remote Patient Monitoring Devices

Industrial & Utility

Smart Meters (e.g., electric, water, gas)
IoT Sensors in Agriculture (e.g., soil moisture sensors)
Connected Factory Equipment
Smart Fleet Trackers
Environmental Monitoring Sensors (e.g., air quality sensors)

Project - Remote control vehicle

R2, 3 & 7

Avoiding interference

If two or more micro:bits are transmitting data there is a chance that they will interfere with each other. 

One vehicle might be receiving data intended for another vehicle. 

To prevent this you must use your own radio group number which we will give you.

Keep it secret or someone may hack into your buggy.

RCV Buggy

One micro:bit is coded as the buggy's micro:bit. 

RCV Hand held controller

A scond micro:bit is coded as the hand held controller. This microbit will be used to send instructions to the buggy  using radio signals.

Remember, if two or more micro:bits are transmitting data there is a chance that they will use the same radio group number and interfere with each other. 

Each learner must be given their own radio group number to prevent interference. 

They must keep it secret or someone may hack into their buggy.

So they should NOT use radio group 42!

Testing

Follow these instructions carefully:

1. Place your buggy on the floor.

2. Turn the motor board on.

3. Make sure your controller micro:bit is on.

4. Finally, turn the battery pack on your buggy on.

5. Experiment with pressing both buttons A and B on the controller micro:bit to go forwards, button A to turn right,  button B to turn left and pressing the micro:bit logo (V2 micro:bits only) to go backwards.

OUT OF CONTROL!

If your buggy goes out of control, just pick it up and turn the battery pack off.

When you are ready, start again.

Practise steering your buggy until you can keep it under control.