Water Dispenser - Lesson Plan

Overview During this lesson, students will gain understanding of the positive and negative ways that humans can impact on the environment. Students will design and create their own self-monitoring SAM Water Dispenser, one possible solution to the issue of water scarcity. It is recommended that this lesson is split into two 45-minute instructional periods.

Key Information Level 4: (Ages 10-12) US Grades 5 or 6

Lesson consists of...

Time: 45/90 minutes

Learning Objectives

Warm-Up

5 mins

Mini-lesson

10 mins

Worked Example

7 mins

Challenge 1

25 mins

Challenge 1 - Debug

5 mins

Challenge 2

7 mins

Tidy Up / Exit Ticket

4 mins

As a result of this lesson, students will be able to ➜ Identify positive and negative ways that humans can impact on the environment. ➜ Recognize the causes of water scarcity and consider what humans can do to help prevent it. ➜ Build a SAM Water Dispenser to monitor and indicate the depth of water. ➜ Program a self-regulating water monitoring and dispensing system using SAM blocks and other materials.

Lesson Topics Life Science ➔ Monitoring and minimizing a human impact on the environment Computing ➔ Inputs, outputs, abstraction, debugging

Scientific Thinking ➔ Constructing Explanations and Designing Solutions

Design and Technology ➔ Generate, develop, model and communicate ideas through talking, drawing and mock-ups

English Language Arts ➔ Participate in collaborative conversations

Materials required

➜ ​SAM Labs Kit

➜ Scissors / Craft Knife

➜ Thick ​Card / Cardboard

➜ ​Rice

➜ ​Container

➜ Lollisticks

➜ ​Student Workbook

➜ ​Blu Tack

➜ ​Yogurt Pot

➜ ​Double Sided Tape

➜ Cello​tape

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Warm Up – ‘Positive or Negative’

5 minutes

Which human actions impact positively or negatively on the environment?

Objective: ​Classify common human actions according to the effect these have on the environment.

Procedures​: ​“Today we are going to learn about how humans can have both positive and negative environmental impact. develop a feasible solution to one of these - the effect of water shortage in developing countries.” ● Explain that many of the things that humans do in the world can greatly affect the environment. ● Take some suggestions from students and create a mind map of these. ● Students look at the pictures of the different environmental impacts on IWB slide 1 and join each picture to either the statement ‘Positive’ or ‘Negative’.

Link forward:​ What effect can water shortage have on developing third world countries, especially those where there has been little rainfall?

Mini-lesson

10 minutes

What is water scarcity and what causes it?

Objective: ​Understand why there is water shortage and what humans can do to help prevent it.

Procedures: ● Focusing now on the effects of water shortage, explain that in many areas of the world, there is a chronic lack of water. ● This is particularly true for developing third world countries and environments where there are high levels of agriculture and/or droughts. ● Explain some of the key factors relating to water shortage, for example, climate change, deforestation, pollution and everyday wasteful uses of water, such as taking baths instead of showers or leaving the tap running when you brush your teeth.

Accompanying video - ​clip ​(https://www.youtube.com/watch?v=XGgYTcPzexE)- explores the main reasons for water shortages across the world.

Let’s Discuss: ​What causes water scarcity?​ ​In your workbook or with a partner, record, discuss, or share your ideas as to what we can do to help prevent water shortage.

Keywords

● Physical water scarcity ● Deforestation ● Economic water scarcity ● Pollution ● Climate change ● Water wastage

Link forward:​ Students will make a self monitoring water dispensing machine, using materials provided and SAM blocks.

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Worked Example

7 minutes

Design a SAM traffic light based water level monitoring system that will display one of three colors depending on the amount of light (and therefore water level) that is present.

Instructions

Workspace

Notes for Teachers

The Light Sensor (our input) will react to the amount of light that is present. The RGB LED (our output) will display light. If you do not have a Light Sensor, you can use a Slider or Virtual Slider block.

Step 1.

Turn on and pair: ● 1 Light Sensor block. ● 1 RGB LED block.

Step 2.

Drag the Light Sensor block and RGB LED block onto the workspace and connect them.

Notice how the brightness level on the RGB LED decreases when you cover the Light Sensor and vice versa.

Step 3.

Drag 3 Color blocks onto the workspace. Select the settings icon and change one to red, one to amber and one to green. Connect each one to the RGB LED.

In our system, we want the RGB LED to indicate the depth of water. To do this, we will need to program it to display one of these 3 different colors. The red color will indicate when the water level is too high, the amber color will indicate an average depth of water level and the green color will indicate when the water level is low.

Step 4.

Drag on 3 separate Filter blocks and join each one to each of the color blocks.

The Filter block only allows certain values through.

Step 5.

Press the setting icon on each Filter block and set each one to the following values: ● 76 - 100 (green) ● 51 - 75 (amber) ● 0 - 50 (red)

Step 6.

Connect the Light Sensor block to each of the Filter blocks and test it out by slowly

This will ensure that the RGB LED displays one of the 3 colors depending on the amount of light.

The RGB LED should shine green when there is lots of light present (76 - 100 filter value), amber when there is a some amount of light present (51 - 75 filter value) and red when their is very little light present (filter value 0 - 50). Ⓒ 2018 SAM Labs

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covering and uncovering the Light Sensor.

Challenge 1 - ​2 parts Lesson 1: Building The Model & Lesson 2: Creating The System

25 minutes (per lesson)

Build a SAM water monitoring model that clearly indicates when water depth has reached a certain level.

Instructions

Workspace

Notes for Teachers

Lesson 1 The picture here is of a completely made model.

You can either decide to follow the steps below in order for students to make the same model or you can instruct students to design and make their own similar model (workbook challenge 1).

Either way, it is recommended that the design/building of the model (steps 1 - 11 if you are making this same model) is done within one lesson and the building of the system itself (steps 12 - 22) is done within a separate second lesson.

* Make your own self regulating water dispersing machine using the craft materials and SAM blocks provided.

Make sure the hole you cut is not too large (it only needs to be large enough to let the rice drop through it).

The hole must be smaller than the ‘plug’ part of the model which will need to fit flush underneath it without any gaps.

Use Blue Tack or double sided sticky tape to stick the Light Sensor to the inside of the Yoghurt Pot.

The Light Sensor should be stuck towards the top of the yoghurt pot.

Step 1.

Cut out a hole in the bottom of a Yoghurt Pot.

Step 2.

Fix the Light Sensor to the inside of the Yoghurt Pot.

Step 3.

With the RGB LED inside its lego case, attach this to the Car base.

Placing the RGB LED inside the Car base will ensure that it is visible.

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Step 4.

Attach the wheel to the DC Motor.

Make sure that the flat end of the DC Motor’s axle lines up with the flat end within the tyre, so that it fits on more easily.

Step 5.

Place the DC Motor in the Controller.

This will provide the ideal height for the DC Motor to attach to the side of the container.

Step 6.

Stick the controller to the side of a container.

Step 7.

Using Blue Tack, stick a Lolly Stick to the centre of the wheel.

The easiest and most secure way to do this is to use Blue Tack.

To ensure that the container remains flat on the desk, you might want to secure it with Blue Tack.

Make sure that the Lolly Stick is fixed securely to the wheel and it sits at a 90 degree angle.

When the wheel rotates the Lolly Stick must stay attached to it.

Step 8.

Cut out a large circular piece of thick card or cardboard and attach this to the end of the Lolly Stick.

This part of the model will act as the ‘plug’, therefore it it must be significantly larger in size than the hole that you cut out at the bottom of the yoghurt pot (you might wish to check that this is the case by holding the yogurt pot above it to check).

The easiest way to do this is by using Blue Tack.

Make sure that the Car base sits level to the centre of the ‘plug’.

Step 9.

Attach the Car base to the side of the container.

Step 10.

Stick the yoghurt pot to the Car base at such a height that the ‘plug’ sits flush underneath it.

One way to do this is to attach another Lolly Stick to the side of the Car base and using either double sided tape or Blue Tack, stick the yoghurt pot to the Lolly Stick.

Make sure that you stick the Yoghurt Pot securely to the Car base. You could tie an elastic band around the Yoghurt Pot and Car base later on, if when testing it out you find that it is not secure enough to hold the weight of the rice.

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Step 11.

Check that you have the Yoghurt Pot at the correct height by carefully moving the ‘plug’ from left to right, making sure that it moves away and then back underneath it again fluidly.

You should notice that the ‘plug’ slides away from the yoghurt pot and then fits flush underneath it once you move it back again.

* It is recommended at this point that teachers finish the and complete the following steps within the next lesson).

Lesson 2 Step 1.

Starting with the system in the worked example, drag on 3 On/Off blocks and connect each one between each Filter block and Color block.

Step 2.

Drag on 3 Interval blocks and connect each one between each On/Off block and the RGB Light.

The ON/OFF block turns any sensor into a button so it is helping convert the input through as a button to help activate the flow into the colour block and then to the light.

The Interval block will enable each RGB Light color to flash on and off

Step 3.

Set each Interval Block to the following values: ● Interval block 1

(connected to the green color block): 1 second 500 ms ● Interval block 2 (connected to the amber

color block): 1 second ● Interval block 1 (connected to the red color block): 500 ms

Each RGB Light color will flash for the amount of time you set it each one too. The red color block is set for the lowest amount of time as this is the one we want to flash the quickest, in order to signify the warning sign.

Step 4 Add a Threshold block and join this to the Light Sensor block.

Here, the Threshold block is used as an alternative to the Filter block.

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Step 5.

Press the setting icon on the Threshold block and set it to 10-100 True and 0-10 False.

The Threshold block only allows certain values through. Numbers above the threshold become true and numbers below the threshold become false.

Step 6.

Drag on an Inverse block and join this after the Threshold block.

We only want Light Sensor values up to 10 to come through this part of the system, therefore by using the Inverse block, 0-10 now becomes ‘true’.

Step 7.

Drag on an Interval block and join this after the Inverse block.

The Interval block creates pulses of time. This will ensure that the output (Sound Player) keeps playing all the while the RGB Light is on red.

Step 8.

Press the setting icon on the Interval block and set it to 500ms.

Step 9.

Drag on a Sound Player block and join this after the Interval block.

Step 10.

Press the setting icon on the Sound Player block and choose the Submarine Alert Sound File from the Sound FX 2 Category.

Step 11.

Test your system.

This will cause the output (Sound Player) to keep repeating every 500 milliseconds.

The Sound Player will be the second output to this system. It will play a warning sound to indicate that the RGB LED is flashing red.

This is probably the most relevant sound effect, however you may wish to give students the freedom to choose their own.

Ask students to test the complete system out, using their built model.

To do this, they will need to have both the Light Sensor and RGB LED light turned on and paired.

As in the video example (step 1), students could use rice to represent the water, slowly pouring this until the Light Sensor is completely covered and checking that the RGB LED light flashes correctly and the Sound Player warning sounds when it is flashing red.

Checks for understanding: ​What effect does changing the times on each of the separate Interval blocks have on the system? Which block in the system is being used as an alternative to the Filter block?

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Challenge 1 - Debug it

5 minutes

How will the system work at night?

Instructions

Workspace

Notes for Teachers

This will act as a light source for when it is night time.

Students may wish to stick this to the inside of their containers to see what it will look like as part of their model.

Step 1.

Turn on and pair another ● RGB LED.

Step 2.

Drag on to the workspace 2 Time Trigger blocks

Step 3.​ Set the first time 1 minute away from the present time. Set the second time for a minute later.

Setting the Time Trigger blocks will enable you to set a time for the RGB Light to come on (Time Trigger 1) and go off (Time Trigger 2)

Explain that the times chosen are purely to test that this second system works. In reality, the first Time Trigger (on) would be set to dusk and the second Time Trigger (off) would be set to dawn.

It is important that you press the ‘set’ button otherwise it will not work.

Step 4. ​Drag on a Toggle block and join this to both Time Trigger blocks and to the RGB LED.

The Toggle block will switch the RGB Light on (Time Trigger 1) and off (Time TRigger 2).

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The RGB LED should switch on when it gets to the time set on the first Time Trigger and then switch off when it gets to the time set on the second Time Trigger

Step 5. ​Test it out!

Challenge 2

7 minutes

Add to the system a mechanism for dispensing the fresh, clean water.

Instructions

Workspace

Notes for Teachers

The DC Motor will act as another output. When connected to the model it will move the ‘plug’ away from the part of the system that is holding the water.

Step 1. ​Turn on and pair the DC Motor and drag this block onto the workspace

Step 2. ​Press the setting icon on the DC Motor and drag the speed slider to a quarter of its maximum speed. Also check that the rotation is set to ‘clockwise’.

Step 3.

Turn on and pair the Button and drag this block onto the workspace

In the example model, the DC Motor needs to spin clockwise first in order to move it away from the part of the model holding the water.

We want it to spin at the lowest speed possible as it only needs to move a small enough distance to detach the ‘plug’ from the hole.

The Button will be the input for the third and final part of the system (the part which will control the dispensing of the clean water when it is full).

When it is pressed, it will activate the DC Motor to spin and move the ‘plug’ away from the part of the system that is holding the water.

You can use the virtual Button block if you haven’t got access to a Button.

If students have access to a physical Button, ask them to attach it to their model.

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The Key Press block will act as an input to control the direction in which the DC Motor spins.

Step 4.​ Drag onto the workspace 1 Key Press block and position this just above your Button block.

Step 5. ​Drag on a Toggle Block and join this to the Key Press block.

The Toggle block will act as a switch, to change the direction that the DC Motor spins on and off.

Step 6. ​Drag on a Switch Direction block and join this between the Toggle block and to the DC Motor output.

The Switch Direction block will change the direction the DC Motor spins. This will enable the ‘plug’ on the model to open and close.

Step 7. ​Drag on a Number block and join this to the Button block.

This will allow the DC Motor to be regulated as a specific speed and to turn on/off when the button is pressed

Step 8. ​Press the setting icon on the Number block and change the number to 1.

This is the lowest value you can set it to, which will cause the DC Motor to spin at its slowest speed.

Step 9.​ Drag on another Toggle block and this time join it between the Number block and the DC Motor.

Step 10. ​Test it out!

This second toggle will switch the DC Motor on and off. When the Button is pressed it will switch on and when it is pressed again it will switch the DC Motor off.

Ask students to test out both systems from challenge 1 and 2 alongside their built model.

To do this, it is recommended that you use rice to represent the water (if you find that the rice is too heavy for the Yoghurt Pot, you could use something lighter in weight such as coffee, sugar, salt or sand). Start by slowly pouring the rice into the part of the system receiving the water. As the rice starts to cover up the Light Sensor, you should notice the RGB LIght Ⓒ 2018 SAM Labs

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responding according the the filter settings applied within the system. Once the rice (water) completely covers the Light Sensor the RGB Light should flash red and the Sound Player alarm should be triggered. At this point, you can use the system from this challenge to move the ‘plug’ to release the ‘water’ (rice) to the collection container.

When pressing the Button double press it quickly as we only want the DC Motor to switch on and off very quickly.

Extension Ideas​: ● Computing/ICT​: ○ Explore ways of adjusting the system so that it works efficiently for a range of water uses. ○ Challenge students to find a way to incorporate the system from challenge 2 within the challenge 1 algorithm, so that the ‘plug’ moves automatically without having to press a separate input. ● Design and Technology​: ○ Design and make a waterproof cover for the Light Sensor. ● Science​: ○ Research different ecosystems where the s ​ elf monitoring water dispensing machine ​could be used. ● Art and Design: ○ Ask students to decorate their model so that it is more aesthetically pleasing. ● Math: ○ Research water usage data from around the world and compare, sort and order these statistics. ● ELA: ○ Write a persuasive piece that encourages others to also think about their use of water.

Checks for understanding: ​What is the function of the Key Press block in this system? What effect does the Number block have on the DC Motor?

Tidy Up / Exit Ticket

4 minutes

Reinforcing the learning objectives of the lesson, students can reflect on key takeaways by completing and submitting an exit ticket.

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