Activity 6: Wireless Sensor Networks

                     

                Activity 6: Wireless Sensor Networks

          Hey Guys, Welcome back to our Blog. This Week we got a 3 course introduction meal to Zigbee. What is Zigbee you ask? Well Zigbee is basically a Wireless Network that allows Devices to "talk" to each other. It can be used to create smart environments with sensors, that feeds information to a main coordinator. For our activity we used 2 Xbee module to communicate with each other. Xbee is an interchangeable module by Zigbee with an antenna to transmit signals. You can slap it on to any device with either an USB adapter called a XBee Explorer Dongle or a RX/TX adapter called a XBee Explorer Reguated for micro controllers in our case an Arduino. Enjoy your meal, Bon Appetit !

The first Course: Hors D'voure (the starter)

          Our very first task is to establish a connection within our group. In order to do this we first need to know the serial numbers for both modules. We connected our Xbee to the XBee Explorer Dongle and hooked it up to our computer. Then we had to open up our pre-downloaded XCTU on our computer. Our group faced a few problems in this part. Our first problem was our computer couldn't find the Xbee. In order to solve this problem we had to try all the USB ports on our computer. Then we had to copy down both modules serial high and serial low number and register them in the other one. Our group modules couldn't link with each other as we forgot to press Write in order to save the serial numbers into each module.

Registering the Serial Numbers

         Once we had establish a connection we had connect a circuit to the Arduino and code the Arduino such that when it received an 'a' form our computer it would light up a LED and turn off the LED when it received a 'b'.

Circiut Connection

The second course: The Main Dish

          The next thing we need to do was to communicate with another group. To do this we had to get their serial number and give them ours to link up the modules. 

Hard at Work Connecting and Writing the Other Group Serial Numbers

           One group had to connect a "Switch" circuit and acted as a switch to on the other group "buzzer" circuit.

Switch Circuit

Buzzer Circuit

The last course: The Dessert :D

            The last thing we had to do was to send data to our lecturer. Basically we had to combine our sensor code from our week 1 with the code that sends the data. Unfortunately we all had a problem and couldn't send the data properly over.

           Ok guys this brings us to the end of our activity. We hoped you enjoyed this meal as much as we did. See you next week !

Activity 5 : Water Treatment (Sedimentation and Filtration)

Activity 5 : Water Treatment (Sedimentation and Filtration)

We had done with the activity related to coagulation and flocculation during week 2 of our module.This week, we are doing the activity the other two water treatment process which are sedimentation and filtration.Before the lesson,we were instructed by our lecturer to watch the videos which uploaded by him to eduCanon.The videos gave us some ideas about what we will be doing during our lesson.

Filtration and Sedimentation

Our first activity is Sedimentation and below are the materials needed for our first activity.

Clear Water, Cooking oil, Small balls

First, we are required to calculate the settling velocity of the small ball in clear water and cooking oil using the formula below:

Here is our calculations:

After that, we start our activity to find out the experimental values of the 2 different situation. Due to the distance is needed to calculate the velocity, so we measure the length of the fluid contained in two bottle first before we start.

 

We put the small ball slowly to the oil and water and video recording the process using UberSense apps which we required to install it before our lesson. This app enable us to determine the time at which the small balls pass through each position by scrolling through the video.

Small ball passing through water 

Small ball passing through oil

We carry out the experiment twice in order to get more accurate results by calculating their average values.

Experimental results

Although that our experimental values are different with our theoretical values, but we can conclude that small ball travels faster in water than in cooking oil according to our experimental results. This is because the cooking oil is more viscous than the water.

Our second activity is to build an effective rapid water filter by using the materials given to our group: 

 

For our group, we are going to use gravel as our bottom (4 cm) and charcoal on top (3 cm).

After building our water filter, we need to clean our filter with about 1 litre of clean tap water before we pour in the dirty water.We are required to filter 3 water samples and each samples must be at least 100 ml.Due to the limitation of time, we need to shake our water filter slowly to increase the speed of its process in order to finish our experiment on time.

After getting the samples after filtration, we have to measure the turbidity, pH and conductivity of water before and after the filtration.

Measuring turbidity

Measuring pH

Measuring conductivity

This is the final result which we get from our filtration activity:

According to our results, it is quiet unexpected that our turbidity decreases because at first we think that it might be become more dirty because of the charcoal.However, we know that the first step, which is rinse our filter with tap water had greatly reduces the impurities of our filter system after our discussion. Besides that, the pH of water after filtration had increase about 3 because the charcoal is alkaline.

From these two activity, we learnt more about sedimentation and filtration. We also learnt about how to get a clean water and build water filter system. However, although the filtered water is clean, but it is still not suitable for drinking because it contains bacteria and microorganism which cannot be filter.

That's all for our this week's activities. Thank you for reading. 

Activity 4: Water Distribution

Activity 4: Water Distribution

Characterising a pump

           Have you ever wondered how the water in your taps, sink and showers get in to your homes? Well first we have to look at where all the water in the world are found.

            So as you can see there is only about 2.5% of freshwater on our planet. Then 68.8 % of that freshwater is frozen and another 30.1% are underground. The remaining freshwater found on the surface is all in our lakes and reservoirs. So now you know where the water comes from but how does it arrive in your homes? The answer to that question is pumps. Pumps Pumps all have different flow rates. Our Mechanical teacher for ED Mr. Tune thought us the way to obtain the characteristics of the pump, In order to obtain the characteristics of the pump we had to plot a graph of Head (H) which is height of the pump to the surface of the water against Mass flow rate (Q) which is the amount of water we collected in a certain amount of time.

            In order to get these information this we had to conduct an experiment. The following things were needed:

-1 Big Bucket

-1 Small Bucket

-1 Measuring Tape

-1 Pump

- 1 Pipe (1m long)

- 1 Stopwatch (On our Ipad/Phone)

Mass of the empty small bucket

The first thing we had to do was to find the maximum height of water our pump could pump.

The maximum height was about 60 cm.

Then we had to obtain the mass of water our pump could pump at intervals of 10 cm. We planned to conduct each test with the time limit of 60 sec.

Keeping track of the time

 To obtain the mass of the water we had to take our obtain the mass with the bucket with water and subtract the mass of the empty bucket.(All pictures with mass includes bucket mass)

At 50 cm

At 40 cm

At 30 cm

At 20 cm

At 10 cm 

At 0 cm

Finally its time to plot the graph

           

            So in order to plot the graph we needed to divide our mass by the time taken to get (Q). And plot (Q) against (H).

Our graph

Now that we were done with the pump its time for math!

After the pump experiment our Math Teacher for ED Dr. Xin Yi showed us how to find the best straight line using excel. As well as explaining what is correlation coefficient. Correlation Coefficient is basically how many points are on the best straight line. r ² is the percentage of total variations of the points on the line.

That's the end of this week activities. See you next week. Thanks for reading! 

SPECIFICATION REPORT

Project statement

The Water Surveyor

Data required from a water body are usually taken during surveys. The pattern of the survey depends on the vehicles designed. Often boats tow sensors. The process can be also be replaced by autonomous vehicles to get uniform data in terms of depth and location.

Can we design a vehicle to take measurements of temperature of the surface in a lawn mower pattern?

Functions of the vehicle

This vehicle will be able to detect the temperature of the water surface with an accuracy of 0.1 degree celsius using the temperature sensor that we did during week 1 activity. It can be operated by 2 ways, the first is automatic control and the other is by man control.

For the automatic operation, the vehicle will be able to move by itself intelligently without people controlling.This is definitely more work-efficient and reduce unnecessary man-power.  When it reaches the end of a lane, it will change directions to the next lane, which means that which it reaches a specific distance, it will automatically turn 90 degree and so on until a lawn mower pattern is achieved. If there is an obstacle halfway, the vehicle is able to detect the obstacle and send message to warn the users ( man control ) or it can automatically dodge the obstacle (automatic control).

If the automatic system malfunctions, we can switch to the man control to control the movement of the vehicle. It is a prevention for accident from happening.

Not only that, our vehicle will move in a lawn mowing pattern to obtain the temperature of surface water at different position from time to time in automatic mode. Why lawn mowing pattern? This is because by moving our vehicle with lawn mowing pattern, we can obtain data with larger coverage of area on water and also more detailed results of water temperature.

A phone app will be created for this vehicle. This apps can collect data of the water surface temperature from the vehicle and calculate out the average temperature for the surface water. Message of warning will be sent to the users through the apps when the temperature of water is whether too high or too high . This function is indispensably essential especially to biologists for them to prevent algae bloom. Early blue–green algae blooms usually develop when water temperature is higher and there is increase of light. Water temperatures above 25°C are optimal for the growth of Cyanobacteria. Hence, our product is important for biologists to take control of water temperature so that they can prepare precautionary steps to counter the algae bloom problem.

Sketches:

IDEA 1:

TOP VIEW

• When the edge knocks into the end of a lane, the case will be pressed and compressed which then hit the button. Then the vehicle will start to change direction.

Improvement:

• Main material: aluminium and polystyrene
• Ultrasonic sensor in front of the vehicle and the sides to detect obstacle or wall.
• Temperature sensor on the boat body which carries the electronic circuits.
• Thruster at two sides of the vehicle.

How the sensors work?

The vehicle start at position 1. At position 2, it getting near to the end, the front sensor and the right side sensor will activate and start to slow down by reversing the direction of motor. The vehicle will stop at position 3. It detects the wall is at the right and so take the first turn to left and turn again to left. For the rest directions turn will be alternative for example right-right, left-left, right-right and so on.

At the position 4, the vehicle slows down and stop at position 5. It turn left and left again. At position 6, even the front sensor and the right sensor is activated, but it will not affect the direction as the program is affected by the two sensors only during the first turn and not the second turn at any turn points.

At position 7, the vehicle is support to take the first turn to right but because the right sensor is activated so it affects the program and stop the vehicle at that point.

SIDE VIEW

Motor directions:

• The diagram shows how our thrusters or propellers change the direction of vehicle, whether to right or left.
• For example,if we want our vehicle to turn left, we program our propeller in a way such that the left propeller turns in reverse direction ( anti-clockwise ) while the right propeller turns in forward direction ( clockwise ) and vice versa.

IDEA 2:

• Sphere form vehicle with two thrusters or propeller at two sides.

Disadvantage:

• It is tough to find out its centre of gravity, which makes it unstable.

Phone Apps Control:

• Temperature reading up to one decimal place is shown clearly to the users.
• Control the movement of vehicle using the arrow buttons on the screen.
• The pink dot on the screen indicates the position of the vehicle, while the orange line indicates the pathway of the vehicle.
• Notice that there is a message icon on the bottom left, it is to alert the users when the temperature of water gets too high or low as well as indicating if there is an obstacle.

Other pattern of design:

• Basically a rocket-like boat with a streamlined body design.
• Has three thrusters or propellers serve as propulsion device.

• Center of body floats on air supported by two sides of thrusters on water.

Disadvantage:

• Has high centre of gravity, which makes it difficult to achieve stability on water.

Improvement:

• Lower centre of gravity
• Can be controlled to achieve desired stability on the water surface.

Sensors and Electronics:

• Temperature sensor (we already have one)
• Arduino board (we already have one)
• Arduino motor shield

~allows you to be able to power a motor with a separate power supply of up to 12v.

• motors (x2)
• Transistor
• InfraRed photodiode (x3)
• InfraRed LED (x3)
• Ultra sonic sensor (x3)

Building Materials:

• Acrylic
• Polystyrene foam
• Aluminium hollow or solid shaft
• Spring