Score. Test. Issued. Date. Name:

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1 Name: Date Issued Test Score 1073

2 2 Workbook Summary To learn about Arduino electronics. To learn how to upload a code the Arduino UNO board. To learn the basic principles of electricity. To learn about basic electrical components. To learn how to design simple electronic circuits. To learn making interactive projects. To learn the basics of Arduino coding.

3 3 Arduino Board An Arduino board is a circuit board that combines a microcontroller, inputs, and outputs. A microcontroller is a small computer on a single integrated circuit that contains a processor core, memory, and programmable input/outputs. The important part for us is that a microcontroller contains the processor (which all computers have) and memory, and some input/output pins that you can control. Often these are called GPIO - General Purpose Input Output Pins. An Arduino board can use sensors to sense the environment and receive user's actions to control lights, motor rotation, etc. To make and interactive project like these, we need to assembly a circuit (hardware) and write some code (software). Computer hardware is the collection of physical parts of a computer system. This includes Arduino boards, sensors, wires, breadboard, and electronic components. Computer hardware is items that you can physically touch. Software is a general term for organized collections of computer data and instructions. Software is often broken into two major categories: system software and application software. System software is software that provides the basic non-task-specific functions of the computer. Application software designed for users to accomplish specific tasks. There are several models of Arduino Boards. However, the code between boards of different types is generally universal (some boards may not be completely compatible because of the differences in hardware). Popular boards include UNO, Micro, Nano, and Mega: UNO MICRO NANO

4 4 The board used in this workbook is the UNO, and it is fully compatible to other Arduino UNO. ADiagram of a UNO board is shown below: Reset button Digital I/O ports Power ports Analog I/O ports Digital I/O ports are used to connect to other components or modules, to receive an input signal, or to send a control signal. Usually, we name it by adding a "D" in front of the number, such as D13. The USB interface is used to provide power, upload code or communicate with PC. The L LED is connected to digital I/O (In/Out) port 13 (D13). The TX & RX LEDs are used to indicate the state of the serial communication if the USB interface is transmitting or receiving information. The DC interface is connected DC power to provide power for the board. Power ports can provide power for electronic components and modules. Analog I/O (In/Out) ports can be used to measure analog signals. The ON LED is used to indicate the power state. While the various components are shown on this diagram, they do vary in location depending on the model and manufacturer of the board. Most notably the Reset button, LED L, LED TX, LED RX and LED ON tend to be the most commonly varied. However, they are normally labeled beside each component on the board. The UNO is the most suitable board to complete the experiments in this book. However, you can also use an Arduino MICRO, Arduino NANO, Arduino MEGA or any other boards compatible with them.

5 5 Label the following: Analog In/Out ports D13 LED Power LED USB interface LED TX DC interface Power ports Reset button Digital In/Out ports LED RX

6 6 Compete the following: 1) What does the LED ON light indicate? 2) Where do you connect a PC to the Arduino Board? 3) If a port is an I/O port, what does this mean? 4) To which Digital I/O port is the LED L light connected to? 5) From what connection point does the board get power from when it is communicating with a PC? 6) How many Digital Input ports are there? 7) How many GND (Ground) ports are there?

7 7 Draw a line from each the following labels to the item on the UNO board below: Analog port A4 D13 LED Digital port D2 Transmit serial communication LED (TX) Receive serial communication LED (RX) DC power supply socket Reset Button Power light Digital port D13 One of the Ground ports. USB interface socket Digital ports D0 to D7 Score pages 1 to 7 Correct mistakes Rescore

8 8 Arduino Software Arduino Software (IDE) is used to write and upload the code for Arduino Board. IDE stands for Integrated development environment. IDE is software that combines the basic tools coding developers need to write and test software. Typically, an IDE contains a code editor, a compiler and a debugger. Thus, this will be used to code the application software for your project and upload the coding into the memory of the Arduino Board. The system software is already coded into the microprocessor. The interface of Arduino Software is as follows: Text editor area Configured board and serial port

9 9 Program codes for the UNO are written using Arduino Software. These programs are also called sketches. These sketches are written in the text editor and are saved with the file extension.ino. The editor has features for cutting/pasting and for searching/replacing text. The message area gives feedback while saving and exporting and also displays errors. The console displays text output by the Arduino Software (IDE), including complete error messages and other information. The bottom right-hand corner of the window displays the configured board and serial port. The toolbar buttons allow you to verify and upload programs, create, open, and save sketches, and open the serial monitor. The various toolbar buttons are as follows: Verify: Checks your code for errors while compiling it. Upload: Compiles your code and uploads it to the configured board. Compiling is the conversion of your coding into a machine-code or lower-level form in which the microprocessor can run. New: Creates a new sketch. Open: Presents a menu of all the sketches in your sketchbook. Clicking one will open it within the current window overwriting its content. Save: Saves your sketch. Serial Monitor: Opens the serial monitor. The serial monitor is a window which can be used to send and receive text messages to and from the Arduino board. It is also useful for receiving information from the board. Additional commands are found within the five menus: File, Edit, Sketch, Tools, Help. The menus are context sensitive, which means only those items relevant to the work currently being carried out are available. Compete the following: 1) What does IDE stand for? 2) What three items do IDE typically contain? 3) In what part of the Arduino IDE does the coding get placed? 4) In what part of the Arduino IDE do error messages get displayed? Score pages 8 to 9 Correct mistakes Rescore

10 10 Testing of Arduino UNO board In this next section, you will run the Arduino IDE and test that it connects to your Arduino UNO board. It will also test that coding can be sent to the UNO and that the basic functions of the UNO operate correctly. To complete this exercise, you will need the following: 1x 1x 1x PC with the Arduino IDE software installed. PC to Arduino Board USB cable Arduino UNO board Once you have the above item complete the following steps: Step 1: Open the example sketch "Blink" with Arduino Software. Step 2: 2 Select board "Arduino/Genuino Uno".

11 11 Step 3: 3 Connect UNO to computer with USB cable. Step 4: 4 Select the serial port. Your serial number may be different from the following figure. If it is not detected immediately, please wait for a while, then click "Tools" to check again. Compete the following: 1) What is the number of the COM port that appeared?

12 12 Step 5: 5 Click "Verify" button. The following figure shows the code is being compiled. Wait a moment for the compiling to be completed. Figure below shows the code size and percentage of memory used on the board by the code. Step 6: 6 Check the Message Area and Console Area to confirm that there are no errors. Usually, when we write code, if it has a coding error, the interface will prompt the error message. Coding errors where the IDE cannot understand the code are called syntax errors. If these occur, then the compiling cannot be completed and none of the following steps can be completed until these errors are corrected. Compete the following: 1) Were there any syntax errors?

13 13 Step 6: 6 If there are no errors, Click "Upload" button. The figure below shows code uploading to the UNO board in the message area. Wait until the uploading is completed.

14 14 Step 7: 7 Now we need to confirm that the program is operating correctly. Check to see if the LED marked with "L" on UNO is blinking. If it is, then it indicates that the code is running now and that the basic functions of the UNO are working. blinking Now we have completed the first use. Compete the following: 1) Circle the button used to verify the code? 2) Circle the button used to compile the code? 3) Circle the button used to upload the code to the UNO board?

15 15 Compete the following: 4) Where does the cable from the PC connect to the UNO? On the following diagram point to it with an arrow. 5) In which section of the IDE does the coding get placed? On the following diagram, draw a red circle around this area. 6) In which section of the IDE does it show if there is a syntax error in the coding? On the adjacent diagram, draw a green circle around area. 7) In which section of the IDE does it show which PC communication s (COM) port the UNO board is connected? On the adjacent diagram, draw a blue circle around area. Score pages 10 to 15 Correct mistakes Rescore

16 16 Electronics Basics: Electrical Circuits In order to understand even the simplest concepts of electronics, one must first understand what electricity is. After all, the whole purpose of electronics is to get electricity to do useful and interesting things. The concept of electricity is both familiar and mysterious. You probably have a rough idea of what electricity is based on practical experience. In particular, consider these points: The electricity flows through wires. Electricity comes from power plants that burn coal, collect solar energy, catch the wind, or harness nuclear reactions. Electricity travels from the power plants to our houses in big cables hung high in the air or buried in the ground. Once it gets to our houses, it travels through wires in the walls until it gets to electrical outlets. From there, we plug in power cords to get the electricity into the electrical devices we depend on every day. Electricity can be stored in batteries. When the batteries stops working, all their electricity is gone. Some kinds of batteries are rechargeable. This means that when the batteries have been drained of all their electricity, more electricity can be put back into them by plugging them into a charger. This transfers electricity from an electrical outlet into the battery. And finally, electricity can be very dangerous. However, what is electricity really? Let s start with three very basic concepts of electricity: 1) Electric charge 2) Electric current 3) Electric circuit Electric charge refers to a fundamental property of matter that even physicists don t totally understand. Suffice it to say that two of the tiny particles that make up atoms protons and electrons are the bearers of electric charge. There are two types of charge: positive (+) and negative (-). Protons have positive charge, electrons have negative charge. Electric current refers to the flow or movement of the electric charge carried by electrons as they jump from atom to atom. Electric current is a very familiar concept: When you turn on a light switch, electric current flows from the switch through the wire to the light, and the room is instantly illuminated. Figure 1:Typical Atom Electric current flows more easily in some types of atoms than in others. Atoms that let current flow easily are called conductors, whereas atoms that don t let current flow easily are called insulators. Figure 2: : Electron flow through conductors

17 17 An electric circuit is a closed loop made of conductors and other electrical elements through which electric current can flow. For example, a very simple electrical circuit such as the one shown in figure 3 consists of three elements: a battery, a lamp, and an electrical wire that connects the two. A switch like shown in figure 4 is usually added to open the circuit and stop the electric current. Figure 4: Basic Electric circuit with switch Circuits can get much more complex, consisting of dozens, hundreds, or even thousands or millions of separate components, all connected with conductors in precisely orchestrated ways so that each component can do its bit to contribute to the overall purpose of the circuit. But all circuits must obey the basic principle of a closed loop. Figure 3: : Very simple circuit To operate, all electrical circuits must create a closed loop that provides a complete path from the source of voltage (in the case of Figure 3, the battery) through the various components that make up the circuit (in Fig 3, the lamp) and back to the source (again, the battery). In the case of the UNO board shown in Figure 5), the closed loop is provided by completing a path from the source of voltage (USB positive terminal), through the various components (UNO board), and back to the source (USB negative terminal). Most USB terminals have 4 connections inside them: +, -, and two data connections. Positive (+) USB terminal Negative (-) USB terminal Current flows through the UNO board Figure 5: Overall UNO board circuit Compete the following: 1) What does electricity typically flow through? 2) Name the three basic concepts of electricity?

18 18 Compete the following: 3) What type of charge do electrons contain? 4) Electric current refers to the flow of what? 5) How do the electrons that carry electric charge move? 6) What are atoms or materials that allow electrons to flow more easily called? 7) What are materials that do not allow electrons to flow easily called? 8) What is an electric circuit? 9) What are the three basic components of an electric circuit? 10) What does a switch do in a circuit?

19 19 Compete the following: 11) Label the follow component in the below diagram? Battery Switch Lamp Wires 12) On the diagram above, draw red arrows on each wire in the direction of the conventional current? 13) On the diagram below, label where the conventional electrical current flows into the board? 14) On UNO board below, label where the conventional current flows out of the board? Score pages 16 to 19 Correct mistakes Rescore

20 20 Electronics Basics: Circuit components Electricity is the flow of electrical energy through conductive materials. An electrical circuit is made up of two elements: a power source and components that convert the electrical energy into other forms of energy. We build electrical circuits to do work, or to sense activity in the physical world. Power supply The power supply of a circuit is the part of the circuit that provides the energy for the circuit to operate. The type of energy supplied in an electronic circuit is electrical energy. It is divided into two types of power supplies: DC power and AC power. The supply voltage of DC power supply remains the same over time. Examples of a DC power supply are batteries and power adapters. Voltage of AC power supplies changes periodically with time. Its most common form is sinusoidal voltage. It is most suitable for long-distance transmission of electric energy. Because of this, it is used to supply power to homes. Figure 4: : DC voltage over r time Figure 5: AC voltage over time Generally, electronic circuits use DC. Home appliances have electrical circuits that convert AC into DC. These circuits are called rectifiers. A battery or battery pack is a type of DC power supply and can be represented by the following symbols: WARNING!!! The positive and negative poles of the power supply should note be directly connected, otherwise it may burn you and/or cause damage to the battery or power supply.

21 21 Voltage Voltage is the difference in charge between two points in a circuit. Voltage is measured in volts (V) and is technically the potential energy difference between two points. In a formula, it typically has the symbol U. As with other units in the metric system, voltage can also be measured in various multiples of Thus, 1000 millivolts (mv) is equal to 1 volt (V). Similarly, 1000 microvolts (μv) is equal to 1 millivolt. 1kV=1000V 1V=1000mV 1mV=1000μv Voltage is relative. This means that it is always compared to a reference point in a circuit. The reference point or terminal has a voltage of 0V relative to itself. For example, on battery marked with "1.5V", it's positive (+) terminal is 1.5V higher than the negative (-) terminal. If you specify the negative terminal as reference (0V), the positive terminal voltage will be +1.5V. Positive terminal voltage is +1.5V Specify the positive terminal as reference(0v) Specify the negative terminal as reference(0v) Figure 6: Reference at negative terminal Negative terminal voltage is +1.5V Figure 7: Reference at positive terminal In practical circuits, we usually specify negative as reference voltage (0V), which is called "Ground" (GND). The positive is usually called "V CC". The positive and negative of power supply is usually represented by two following symbols: Positive (V CC) Negative (Ground) Figure 8: Schematic symbols for power supply terminals

22 22 Other variation also can be achieved. When two dry batteries are connected in series, the voltage of each point compared to the reference point is as follows: +3.0V +1.5V +1.5V Figure 9: Other reference voltage arrangements Compete the following: 1) What is a power supply? 2) What type of energy does a power supply give to an electrical circuit?

23 23 Compete the following: 3) What are the two main types of power supplies in electrical circuits? 4) In a DC power supply, how does the voltage change over time? 5) How does the voltage change over time in an AC power supply? 6) Where do we typically find AC power supplies? 7) Where do we typically find DC power supplies? 8) What part of a circuit changes AC power into DC power? 9) Define voltage? 10) What units is voltage measured? Score pages 20 to 23 Correct mistakes Rescore

24 24 Current An electric current is a flow of electric charge. In electric circuits, this charge is often carried by moving electrons in a wire. Current is a measure of the magnitude of the flow of electrons through a particular point in a circuit. Current is measured in Amperes, or Amps. The unit of current(i) is ampere(a). 1A=1000mA A closed circuit consists of electronic components that are necessary for the electric current or the electric charge to complete a full loop. Typically, the power supply half of a circuit is not shown. The power supply part of a circuit connects the ground to the positive terminal. In the figure 10: the left circuit is a closed circuit. This means current flows through the circuit. The right circuit is not a closed circuit as it has a gap in it. Thus, there is no current flowing through the wires and conductors because the current cannot jump across the gap. Figure 10: Closed circuit on the left and open circuit on the right Resistance Resistance is a measure of a material s ability to oppose the flow of electricity. It is measured in Ohms. The unit of resistance(r) is ohm(ω). 1000Ω=1kΩ 1000kΩ=1MΩ A resistor is an electrical component that limits or resists the flow of current in an electronic circuit. Resistors that slow down the flow of current lots are said to have a high resistance. Those that slow down the current a little have a low resistance. The coloured bands indicate how much electrical resistance a resistor has. Later we will learn more details about the resistor color codes. Figure 11: Actual resistor on the left and the symbol for a resistor in a circuit schematic on the right. The figure on the left is what some resistors look like and the diagram to its right is the symbol of a resistor represented in a circuit diagram.

25 25 Compete the following: 1) What is an electric current? 2) Current is a measure of what? 3) How is a closed circuit formed? 4) Are the circuits below closed or open? 5) Why are they both open? 6) How would you easily form the above circuit into closed circuits? Score pages 24 to 25 Correct mistakes Rescore

26 26 Converting units Many times, it is necessary to convert between different measurement units while still referring to the same quantity. The procedure to convert any measurement from one type of units into any other type units is as per the following step. 1. Write the conversion as a fraction. This MUST be a fraction that equals one not in numbers but in QUANTITY. 2. Write out conversion calculation. All UNITS must be included. Conversion Calculation QUANTITY in Existing Units * Conversion Fraction = Same QUANTITY in Target Units (ie. the Answer) 3. Cancel any units that are the SAME (ie. have a pair) on both the top and bottom of the answer fraction. 4. Multiply out.. All UNITS must be left in the ANSWER. Converting units: Example Convert 10kΩ (kilo ohms) into Ω (ohms). Step 1: Write the conversion as a fraction. For a fraction to equal one in QUANTITY, the numerator (top part) and the denominator (bottom part) must be equal in QUANTITY. That is they must both represent the same physical thing. Item 1 must represent the same as Item 2 in the below fraction for the fraction to equal one in QUANTITY. Item 1 Item 2 For our example, we know by definition that the quantity 1kΩ is equal to 1000Ω. As the conversion fraction must be a fraction which equals on in quantity, there are two possible conversion fractions available. Fraction # 1: Fraction # 2: In both of these fractions, the item represented in the numerator is equal in QUANTITY to the item represented in the denominator. Now we need to select the fraction which has the units in the numerator that match our target units (ie. the units that we are converting to). This will naturally be the fraction which has the units in the denominator that match our existing units (ie. the units that we are converting from). As Fraction # 2 has the units Ω in the numerator, and these are our target units to which we are converting our measurement, this will be the correct conversion fraction. Target Units Selected Conversion Fraction: Existing Units Step 2: Write out conversion calculation. QUANTITY in Existing Units * Conversion Fraction = Same QUANTITY in Target Units (ie. the Answer) 10kΩ * = * QUANTITY in Existing Units Conversion Fraction Convert whole number into fraction format for clarity

27 27 Step 3: Cancel any units that are the SAME (ie. have a pair) on both the top and bottom of the answer fraction. * = * = Cancel top and bottom pairs No pair. So it is not cancelled out. Step 4: Multiply out. All UNITS must be left in the ANSWER. = = 10000Ω Thus, 10kΩ = 10000Ω This method of converting a quantity s units works with all types of units such as metres (m) to millimetres (mm), volts (V) to millivolts (mv), and amps (A) to milliamps (ma) to name a few. Converting units: Simplified Example Task: Convert 5mA (milliamps) into A (amps). Step 1: Write the conversion as a fraction Step 2: Write out conversion calculation. Step 3: Cancel any unit pairs. Step 4: Multiply out. * * * = = = A Thus, 5mA = 0.005A

28 28 Convert the following quantities: 1) Convert 3A (amps) into ma (milliamps)? Step 1: Write the conversion as a fraction Step 2: Write out conversion calculation. Step 3: Cancel any unit pairs. Step 4: Multiply out. 2) Convert 0.1A (amps) into ma (milliamps)? 3) Convert 40mA into A? 4) Convert 125mA into A? Score pages 26 to 28 Correct mistakes Rescore

29 29 Convert the following quantities: 1) Convert 2.5V (volts) into mv (millivolts)? 2) Convert 0.1V (volts) into mv (millivolts)? 3) Convert 100mV into V? 4) Convert 3.5mV into V? 5) Convert 220Ω into kω? 6) Convert 68000Ω into kω? 7) Convert 12kΩ into Ω? 8) Convert 2.2kΩ into Ω? 9) Convert 110mA into A? Score page 29 Correct mistakes Rescore

30 30 Electrical Interactions To understand the relationship between voltage, current, and resistance, imagine this analogy of an avalanche of snow on a mountain. Analogous means to compare two things in certain respects - typically in a way which makes clearer the nature of the things compared. In this case, the analogy is trying to make clearer the nature of electricity. The height of the mountain is analogous to the voltage; the higher the mountain, the more potential energy the falling material has. The amount of snow and rocks in the avalanche is analogous to the current. The steepness of the mountain slope is analogous to the resistance: the steeper the mountain, the less it will resist the flow of the snow and rocks. Voltage (U), Current (I), and Resistance (R) are all related, by the following formula: Volts = Amps x Ohms or rearranged I = U/R Current equals voltage divided by the resistance This shows that if we double the voltage, there will be double the current. Think of it as a mountain double in height. This would mean twice the amount of snow and rocks would roll past you because the snow and rocks would be traveling twice as fast. However, if we double the resistance instead of doubling the voltage, we will decrease the current by half. You can think of this as having a less steep or flatter mountain. This would mean half the amount of snow and rocks would roll past you because it was traveling half as fast down the flatter slope. In the adjacent diagram, the current through resistor R1 is calculated as follows. 1. The voltage, which is represented as U in the formula, is 5 volts (ie. 5V) 2. The resistance, which is represented as R in the formula, is 10kW (ie. 10 kilo ohms). 3. Converted all quantities into standard units (ie. V, A and W). 4. Complete numerical calculations. 5. Convert into requested units if required. I = U/R = 5V/10kΩ = 5V/1000Ω = A = 0.5mA WARNING!!! Do not connect the two poles of power supply with low resistance resistors. This will make the current too high and cause damage electronic components. Power supplies have a maximum amount of current that they can deliver safely. This amount of current is normally found on the manufacture s specifications or data sheet for the power supply. The maximum current that a UNO digital pin can output is 40mA.

31 31 Compete the following: 1) What is a resistor? 2) In the avalanche analogy, to what is voltage similar? 3) In the avalanche analogy, to what is current similar? 4) In the avalanche analogy, to what is resistance similar? 5) What is the formula which show the relationship between Current, Resistance and Voltage? 6) Calculate what the current through R1 in ma? 5V R1 5kW 7) Calculate what the current through R2 in ma? 5V R2 20kW Score pages 30 to 31 Correct mistakes Rescore

32 32 Compete the following: 1) Calculate what the current through R1 in ma? 5V R1 10W 2) Calculate what the current through R2 in ma? 5V R2 220W 3) Calculate what the current through R3 in Amps? 12V R3 680W 4) Calculate what the current through R4 in milliamps? 3V R4 12kW 5) Calculate what the current through R5 in milliamps? 15V R5 48kW Score page 32 Correct mistakes Rescore

33 33 Compete the following: 1) Design a simple electrical circuit that would have a current of 100mA flowing through the resistor. Draw your design to the right. NOTE: In design, anything that is not specified is up to the designer to specify. In this case, neither the voltage nor the resistance has been specified. Thus, you will need to determine both of these items to that the requirement of a current to 100mA is achieved. This may require several attempts to achieve the required outcome. Calculations: Attempt 1 - U = R = I = = Was the required current achieved? If specified requirement not achieved, proceed with the next Attempt and modify variables (ie. U and R). Attempt 2 - U = R = I = = Attempt 3 Attempt 4 If further attempts are required, complete on a separate sheet of paper and attach to this page. Supervisor Initial: Check page 33 activities have been completed and are correct.

34 34 Compete the following: 1) Design a simple electrical circuit that would have a current of 40mA flowing through the resistor. Draw your design to the right. Calculations: Attempt 1 Attempt 2 Attempt 3 Attempt 4 Supervisor Initial: Check page 34 activities have been completed and are correct.

35 35 Compete the following: 1) Design a simple electrical circuit that would have a current of 5mA flowing through the resistor. Draw your design to the right. Calculations: Attempt 1 Attempt 2 Attempt 3 Attempt 4 Supervisor Initial: Check page 35 activities have been completed and are correct.

36 36 Compete the following: If further attempts are required, complete on a separate sheet of paper and attach to this page. 1) Design a simple electrical circuit that would have a current of 75mA flowing through the resistor. Draw your design to the right. Calculations: Attempt 1 Attempt 2 2) Design a simple electrical circuit that has a supply voltage of 10V and would have a current of 75mA flowing through the resistor. Draw your design to the right. Supervisor Initial: Check page 36 activities have been completed and are correct.

37 37 Compete the following: If further attempts are required, complete on a separate sheet of paper and attach to this page. 1) Design a simple electrical circuit that uses a 1000W resistor through with a current of 10mA flow. Draw your design to the right. 2) Design a simple electrical circuit that would have a current of 15mA flowing through the resistor. Draw your design to the right. Supervisor Initial: Check page 37 activities have been completed and are correct.

38 38 Component knowledge So that we can design electronic circuits, we need to learn about various types of components that are used. This will enable one to make better decisions about what to change and how to change circuits should they not work in the desired way. As previously explained, electricity is the flow of electrical charges through conductive materials. An electrical circuit is made up of two elements: a power source and components that convert the electrical energy into other forms of energy. We build electrical circuits to do work, or to sense activity in the physical world. Sensors are components that convert other forms of energy into electrical energy. This way we can electrically read the changes in those other forms of energy. Switches, knobs, light and motion sensors all fit in this category. Actuators are components that convert electrical energy into other forms of energy. Some examples of actuators are light bulbs, motors, LEDs, and heaters. Electronics refers to reading changes in electrical properties as information. For example, a microphone changes sound pressure waves in the air to a changing electrical voltage. This process of changing one energy into another is called transduction, and devices that do it are called transducers. Sensors and actuators are both transducers. Sensors change energy to electrical energy and actuators change energy from electrical energy. Much of the technical work of physical computing is about figuring out what forms of energy a person or environment is generating, and what kind of transducer you can buy or build to read that energy. Figure 12: Microphones are sensors that convert audio energy into electrical energy Jumper A jumper is a wire that is designed to easily connect components together. It has a terminal at each end and can be connected by inserting it onto Breadboard or UNO. Jumpers have different types of ends. An ends that look like a pin is referred to as a male end. Female ends have a hole or slot in them. Thus, jumpers can be divided into the following three types. Jumper M/M Jumper F/F Jumper F/M Figure 13: 1 Various jumpers

39 39 Breadboard Breadboards are like a special group of jumpers all joined together. There are many small holes on a breadboard. These are used to plug in and connect jumpers to other various electrical components to form connections between them. The small holes are connected to some of the other holes inside breadboard. The following figure shows the inner links among those holes. The blue lines show the connections that are usually connected to the voltage reference terminal of a circuit or Ground (GND or 0V). The red lines show the connections that are usually connected to the power supply s maximum positive voltage terminal (Vcc). The green groups are connected too. However, they are usually used for connecting component in a circuit somewhere between the Vcc and the GND. Figure 14: 1 Typical breadboard Figure 15: 1 Push button switch Push button A push button switch has four pins. The two pins shown on the left are connected, and the ones on the right are similar. This is shown in Figure 15. When the push button is pressed, the number 1 pins are connected to the number 2 pin. A switch like this is usually used to turn a circuit on or connect two parts of a circuit together. Light Emitting Diode (LED) A diode is a device with that allow the flow of current in one direction only. A LED is a special kind of diode that emits light when current is flowing through it. A LED will shine only if the long pin of the LED is connected towards the positive terminal and the short pin is connected towards the negative or ground terminal. This is also a feature of the common diode. A diode conducts electricity only if the voltage of its positive electrode is higher than its negative electrode. The terminals must be connected so that the current flows from terminal 1 to terminal 2. If the voltage at terminal 2 is higher than that of the voltage at terminal 1, the diode will stop any possible flow of charged particles and no electrical current will flow through the diode. Figure 16: LED and LED symbol The LEDs cannot normally be directly connected to a power supply, as it can damage the LED. A resistor with certain resistance must be connected in series with the LED in the circuit. The value of the resistor is typically 220Ω when used with a UNO board.

40 40 Compete the following: 1) Why do you need to various types of components to design circuits? 2) In electronics, what is read as information? 3) What are sensors? 4) What are actuators? 5) What some examples of actuators? 6) What some examples of sensors? 7) What is a transducer? 8) Is a transducer a sensor or and actuator? 9) What type of jumper is this? Also, label each terminal type.

41 41 Compete the following: On the breadboard below, color all the other holes that are connected to hole: 1) A in yellow? 2) B in orange? 3) C in black? 4) D in green? 5) E in blue? 6) F in red? C A B D E F 7) On the above breadboard, to what are the holes which you have colored orange usually connected to? 8) On the above breadboard, to what are the holes which you have colored red usually connected to? 9) What is this component called? Label which terminals are connected when component is not activated. 10) What is the component to the right? 11) Show using arrows which direction current flows through it. 12) Score pages 38 to 41 Correct mistakes Rescore

42 42 Project 1.1 Control LED by Manual Button Previously when we were testing the IDE, we made the LED marked with "L" on UNO board blink. Now in this project you will use electronic components to reproduce the phenomenon, and try to understand some of the principles we have learnt. The goal of this project will be to use the push button to make the LED turn on manually when the push button is pushed. To complete this exercise, you will need the following: UNO x1 Breadboard x1 USB cable x1 LED x1 Resistor 220Ω x1 Push button x1 Jumper M/M x2 In this experiment, the LED is to be controlled by the push button, and UNO here only plays the role of power supply in the circuit.

43 43 Step 1: Connect components with jumpers according to "hardware connection" above. 1) Write connected on the following line when this is completed? Step 2: Check the connection to confirm there are no mistakes. 2) Write Connections checked on the following line when this is completed? Step 3: 3 Check that the UNO is on a non-conductive surface like a plastic tray, plastic plate or timber board. 3) Write UNO checked on the following line when this is completed?

44 44 Step 4: Connect the UNO board to the computer with a USB cable being careful to avoid touching any wires as this may cause a short-circuit fault. 4) Is the ON LED lit up on the UNO? Step 5: Push the button to see if it controls the LED. 5) What happens when the button is pushed? Step 6: After you have push the button, release it. 6) What happens when the button is released? Step 7: Unplug the resistor, turn it around 180 and plug it back in. 7) What happens when the button is pushed and released? Step 8: Unplug the LED, turn it around 180 and plug it back in. 8) What happens when the button is pushed and released?

45 45 9) Draw the schematic diagram for the new circuit that you now have as changes have been made to the original circuit design? Step 9: Unplug the USB cable from the computer before proceeding. 10) Write UNO disconnected on the following line when this is completed? Step 10: Redesign the circuit so that the switch is connected directly to the 5V supply terminal instead of between the resistor and the LED. Keep the LED connected to GND but design it so that the LED lights up when the button is pushed. Ensure that the electrical current still passes through the resistor as well. 11) Draw the schematic diagram for the new circuit that you designed? Supervisor Initial: Check activity 11 is correct. Step 11: Once your supervisor has checked your above schematic diagram and sign that it is correct, repeat steps 1, 2, 3 & 4 with you new circuit. 12) Circle the below words as you complete each of the steps 1, 2 3, and Connected 2. Connections Checked 3. UNO Checked 4. UNO On LED lit Step 12: Push the button to see if it controls the LED. 13) What happens when the button is pushed? Step 13: Unplug the USB cable from the computer and pack up equipment. Score pages 42 to 45 Correct mistakes Rescore

46 46 Analog and Digital Signals An analog signal has information that can be represented by a continuously variable physical quantity or property over time. Thus, an analog signal is a continuous signal in value and time. On the contrary, a digital signal is a discrete signal in value over time. Digital signals are either ON or OFF and are never HALF ON or HALF OFF. Most signals in life are analog signals. For example, the temperature during the day is continuously changing. It will not suddenly change directly from 0 C to 10 C. On the other hand, a digital signal is a sudden change. This change is directly from a relatively high voltage (Usually the supply voltage) to a low voltage (Usually GND). This HIGH and LOW voltage represent the digital signal of ON and OFF. HIGH for ON and LOW for OFF. HIGH can also be known as having digital value of 1, and LOW can also be known as having digital value of 0. Thus, when a digital signal changes, it changes directly from 1 to 0. Their difference can be illustrated by the following figure. Figure 17: An analog signal compared to a digital signal In practical application, the frequently used digital signal is a binary signal of 0 and 1. As a binary signal only has two forms (0 or 1), it has strong stability. Low level and high level In electrical circuits, the form of binary (0 and 1) is present as low level and high level of voltage. Low level is generally equal to ground voltage (0V or GND). High level is generally equal to the operating voltage of components (Vcc). The LOW level of a UNO board is 0V and the HIGH level of a UNO board is 5V, as shown in Figure 18. When an IO port on UNO outputs HIGH level, the voltage of the IO port is 5V. This 5V from the IO port can be used to power a component or actuator that uses a small amount of electrical power to run. One such component, is an LED with a resistor. Figure 18: Digital signals compared to voltage When an IO port on UNO outputs a LOW level, the voltage of the IO port is 0V. This would then turn off any component which was connected to that port.

47 Compete the following: 1) Describe an analog signal? 47 2) Give some examples of physical quantities that have analog signals? 3) Describe a digital signal? 4) Give some examples of physical quantities that have digital signals? 5) Why do digital signals have good stability? 6) How is a digital signal of 0 communicated in an electronic circuit? 7) How is a digital signal of 1 communicated in an electronic circuit? 8) On an UNO s IO port, what voltage is a HIGH output signal? 9) What happens when a digital signal is HALF ON? Score pages 46 to 47 Correct mistakes Rescore

48 48 Code knowledge Before starting to write code, we should learn some basic programming knowledge. Writing code is writing in a language that the IDE understands. Thus, it is important to know how the IDE will read the code when it compiles it for the UNO. Just as the English language has rule about how to communicate, so does the IDE and the UNO. The following are like nouns, verbs, adjectives, adverbs, prepositions, etc in the English language. They all have different job and if used improperly will not sound correct to the IDE. The IDE will try its best to understand what you have told it in the code. Comments Comments are the words used to explain the sketches to another person reading the code help the coder remember what they wanted a section of code to do. As such, comments do not affect the running of code. There are two ways to indicate comments in a sketch. 1. Symbol "//" "//" will comment out the content to the right of it in current line: 1 // this is a comment area in this line. The code to the left of "//" will not be affected. Thus, the IDE will encode the delay(1000); for the UNO but not the //wait for a second. 1 delay(1000); // wait for a second 2. Symbol "/*"and "*/" "/*" and "*/" will comment out the content between them: 1 /* this is comment area. */ "/*" and "*/" can be used to comment out multiple lines: /* */ this is a comment line. this is a comment line. The "/*" signals the start of the comment section, and the "*/" signals the end of the comment section. Comments are also useful if you want to keep a section of code that you do not want the UNO to run at the moment but you may want it to run in the future. That way when you do need it, you don t have to type it out again. Comments can also be useful if you want to modify a section of code but want to remember what the section was before you started changing it. To do this you duplicate the section of code that you are proposing to modify and then comment out the duplicated section of code. Then, you can modify the original code but still have a copy of the original code if you need to check it or your new code doesn t work and you need to revert back to the original code.

49 49 Data type When programming, we often use numbers, characters and other data. Arduino code language has several basic data types as follows: int This stands for integer which is a number that does not have a fractional part, such as 0, 12, -1. double A number that has a fractional part, such as 0.1, -1.2, char It means character. Examples of these are 'a', '@', '0' string A group of characters in a particular order such as Test, book, Cool 1. Variable A variable is a label for a section of memory. The data that is stored in this memory section can be changed. A variable requires the coder to define the following three items: a type, a name and a value. Variables need to be defined in the code before they can be used. For example: 1 int i; "int" indicates the type is an integer. i indicates the name of the variable. ";" indicates the end of the statement. Statement are usually written in one single line. These statements together form the code. A statement is similar to a sentence in the English language. After the declaration of the variable, the variable can be used and assigned a value. The following is an assignment of a value to a variable: 1 i = 0; // after the execution, the value of i is 0 "=" is used to assign the value of a variable or constant on the right side of the equals sign to the variable on the left side of the equals sign. A certain number of variables can be declared in one statement, and a variable can be assigned values multiple times (See line 2 and 3 below). Also, the value of a variable can be assigned to other variables (See line 4). For example: 1 int i, m; // two variables declared 2 i = 0; // after the execution of this statement, the value of i is 0 3 i = 1; // after the execution of this statement, the value of i is 1 4 m = i; // after the execution of this statement, the value of m is 1

50 50 Compete the following: 1) What are comments in coding? 2) How do comments affect how a code runs? 3) Write an example of a single line comment? 4) What symbols are used to start and finish a multiple line comment? 5) What other uses do comments have? 6) What are some data types? 7) Give some examples of int data types?

51 51 Compete the following: 8) Give some examples of double data types? 9) Give some examples of char data types? 10) Give some examples of string data types? After the execution of following code: 11) What is the value of the variable i? 12) What is the value of the variable k? 13) What data type is the variable k? 1 int i, k; 2 i = 5; 3 k = 11; 4 k = i; 14) After the execution of following code, what is the value of the variable k? 1 string i, k; 2 i = test ; 3 k = what is it ; 4 k = i; // k = new code Score pages 48 to 51 Correct mistakes Rescore

52 52 Function A function is a collection of statements with a sequence of order, which perform a defined task. It is has similarities to a variable but many differences. It has a type which is based on the final output. It also had a name. However, a function also defines a collection of statements. As an example, below is the definition of a function called blink(). 1 void blink() { 2 digitalwrite(13, HIGH); 3 delay(1000); 4 digitalwrite(13, LOW); 5 delay(1000); 6 } The type "void" indicates that the function does not return a value. Later projects will detail how to return value from a functions. The "()" show that the function does not have any inputs. Inputs are also known as parameters. No content inside the "()" indicates that this function has no parameters. The "{}" contains the entire code of the function. The { indicates the start of the function s statements, and the } indicates the finish of the function s statements. After a function is defined, it is can then be called. Let's call the function void blink(), as shown below. 1 blink(); When the code is executed to a statement that calls a function, the function will be executed. After execution of the function is finished, it will go back to the statement and execute the next statement. In the below code, the statement on line 21 is executed, then line 22 calls the function blink(). So following the blue arrows, the UNO will then go to the definition of blink() which is on line 31. The UNO will then executed the defined statements from line 32 to 36 before returning back to the original section of code where it was called from. Then the sketch will continue execution the statements now following the orange arrows. Line 23 is executed and then line 24 calls the function blink() again. So again, the UNO will find the definition of the function, execute the defined statements and then return back to the original section of code as shown by the red arrows. 31 void blink() { 21 delay(500); 32 digitalwrite(13, HIGH); 22 blink(); 33 delay(1000); 23 delay(500); 34 digitalwrite(13, LOW); 24 blink(); 35 delay(1000); 36 } Some functions have one or more inputs or parameters. When you call such functions, you need to write parameters inside the "()" similar to the below example. The number of inputs required, depends on the number of inputs defined in the definition of the function. In the example below, the function digitalwrite() has two parameters: 13, and HIGH. 1 2 digitalwrite(13, HIGH); // turn the LED on (HIGH is the voltage level) delay(1000); // wait for a second

53 53 Compete the following: 1) In coding, what is a function? 2) When is the code in a function executed? 3) After the code in a function executed, where does the UNO go to find the next statement to execute? 4) What are the inputs of a function called? 5) When a function is called, how many parameters are required? 6) What value is returned from function whose type is void? Score pages 52 to 53 Correct mistakes Rescore

54 54 Project 1.2 Control LED by Arduino The goal of this project will be to use the Arduino UNO to make the LED turn on and off through programing. Component list Components are basically the same with those in the previous project (See page 32). The push button is no longer needed. Circuit Now, let 's use IO port of UNO to provide power for the LED. D13 pin of UNO is the digital pin. It can output high level or low level. In this way, UNO can control the state of LED. Step 1: Connect components with jumpers according to "hardware connection" above. Step 2: Code the sketch into the IDE as per the following instructions.

55 55 Sketch Sketch In order to make the LED blink, we need to make the 13 pin (D13) of UNO output high and low level alternately. We highly recommend you physically type the code in into the IDE instead of copying and pasting it. By this method, you can develop your coding skills and get more knowledge. 1 // the setup function runs once when you press reset or power the board 2 void setup() { 3 // initialize digital pin 13 as an output 4 pinmode(13, OUTPUT); 5 } 6 7 // the loop function runs over and over again forever 8 void loop() { 9 digitalwrite(13, HIGH); // turn the LED on (HIGH is the voltage level) 10 delay(1000); // wait for a second 11 digitalwrite(13, LOW); // turn the LED off by making the voltage LOW 12 delay(1000); // wait for a second 13 } An Arduino sketch s code must contain at least the two functions: void setup() and void loop(). The function setup() runs only once when you reset or power the board. Once the setup() function is completed, the loop() function the runs. Once the function loop() has completed its code, the UNO then goes back to the top of the loop() function and repeats the function again and again in an infinite loop until the UNO is turned off. After Arduino board is reset, the setup() function will be executed firstly, then the loop() function will be executed. Reset Pushing the UNO board's Reset button will cause the code to be execute from the beginning. Also switching on the UNO board's power, finishing uploading the code, or pressing the reset button will all trigger the UNO to execute the loaded code from the beginning. The setup() function is generally used to write code to initialize the hardware. The loop() function is used to write code to achieve certain functions. The loop() function is executed repeatedly. When the execution reaches the end of loop(), it will jump to the beginning of loop() to run again. Reset 1 // the setup function runs once when you press reset or power the board 2 void setup() { 5 } 6 7 // the loop function runs over and over again forever 8 void loop() { 13 }

56 56 Now we will step through the sketch and explain each line of the code. In the setup () function, first, we set the 13 pin of UNO board as output mode. This tells the UNO board to control the state of the pin rather than read the state of the pin. The UNO board will now control and make the port output high level or low level as per the sketches statements. 3 4 // initialize digital pin 13 as an output. pinmode(13, OUTPUT); Then, in the loop () function, set the 13 pin of UNO to output high level to make LED light up. 9 digitalwrite(13, HIGH); // turn the LED on (HIGH is the voltage level) Line 10 makes the UNO wait for 1000ms. That is one second. The delay () function is used to make control board wait for a moment before executing the next statement. The parameter indicates the number of milliseconds the UNO board 10 delay(1000); // wait for a second will wait before moving to the next line of code. Then, the UNO will set the 13 pin to output low level, and LED light will turn of off. One second later, the execution of loop () function will be completed. 11 digitalwrite(13, LOW); // turn the LED off by making the voltage LOW 12 delay(1000); // wait for a second Once the code reaches the end of the loop function (ie. line 13), the UNO will then go back to the start of the loop function (ie. line 8). The loop() function will continue being executed over and over and thus make LED keep blinking. The functions called in the above code are standard function of the Arduino. Standard function are those that have been predefined in the Arduino Software. Those function can be called directly. More common standard functions will be explained in later chapters. For more standard functions and their specification, please visit

57 57 Step 3: Check the connection to confirm there are no mistakes. Write Connections checked on the following line when this is completed? Step 4: Check that the UNO is on a non-conductive surface like a plastic tray, plastic plate or timber board. 3) Write UNO checked on the following line when this is completed? Step 4: Connect the UNO board to computer with USB cable being careful to avoid touching on wires as this may cause short-circuit fault. 4) Is the ON LED lit up on the UNO? Step 5: Verify and upload the code. 5) Is the LED blinking? Step 6: Modify the code so that the LED blinks twice as fast, then re-upload. Step 7: Modify the code so that the LED blinks half as fast as the original code, then reupload. Step 8: Unplug the USB cable from the computer and pack up equipment. Score pages 54 to 57 Correct mistakes Rescore

58 58 Project Using the circuit and hardware from the previous exercise, complete the following project. 1) Using Sketch 1.2.1, modify the coding so that the LED blinks twice as fast. Complete this in the Arduino IDE. In the box below draw the circuit diagram for your circuit. Once you have completed the coding, print it out or write in on a separate piece of paper and stable it to this page. Supervisor Initial: Check Project activities have been completed and are correct.

59 59 Project Using the circuit and hardware from the previous exercise, complete the following project. 1) Code a sketch so that the LED blinks at half the speed that they did in the original sketch (ie. Sketch 1.2.1). Complete this in the Arduino IDE. In the box below draw the circuit diagram for your circuit. Once you have completed the coding, print it out or write in on a separate piece of paper and stable it to this page. Supervisor Initial: Check Project activities have been completed and are correct.

60 60 Debugging Debugging is the process of finding and resolving of defects that prevent correct operation of computer software or a system. If your program won t compile (or it doesn t do what you expect), here are a few things to check that often confuse people: The programming language is case sensitive. In other words, myvar is different than MyVar Whitespace (spaces, tabs, blank lines) are all collapsed to the equivalent of a single space. It is for the human reader only. However, variable names cannot contain spaces. Blocks of code are encapsulated with curly braces { and } Every open parenthesis ( must have a matching close parenthesis ) There are no commas in numbers. So you must say 1000 and NOT 1,000. Each program statement needs to end with a semicolon ;. In general, this means that each line of your program will have a semicolon. Exceptions are: Semicolons (like everything) are ignored in comments Semicolons are not used after the end curly brace. } Compete the following: 1) What is debugging? 2) Is myfunction the same as MYfunction in programming language? 3) What must every open parenthesis have? 4) Are commas allowed in numbers? 5) What MUST each statement end with? Score page 60 Correct mistakes Rescore

61 61 Compete the following: SELF TEST Supervisor Initial: 1) On a UNO board, what does the LED ON light indicate? 2) Before connecting a UNO board to a computer with a USB cable, what three things are to be check? 1: 2: 3: 3) Circle the button used to upload the code to the UNO board? 4) Give some examples of double data types? 5) What is a resistor? 6) What are the two main types of power supplies in electrical circuits? 7) If a port is an I/O port, what does this mean?

62 ) Draw a line from each the following labels to the item on the UNO board below: Analog port A4 D13 LED Digital port D2 Transmit serial communication LED (TX) Receive serial communication LED (RX) DC power supply socket Reset Button Power light Digital port D13 One of the Ground ports. USB interface socket Digital ports D0 to D7 20) Design a simple circuit that would have a current of 50mA flowing through the resistor. Draw your design to the right. 21) Make a simple project using a UNO which contains all the following features: 1 LED, 1x220W resistor, and UNO as per the circuit diagram to the left. Make the LED blink using coding The duration that the LED is on during each blink needs to be twice as long as the duration that the LED is off. Complete the coding in the Arduino IDE, compile and upload to the UNO. Show your supervisor the working project. Once the supervisor has seen the working project, then print or write out the code on a separate piece of paper and attached it to this page.