ELEC360 Signals And Systems Essay.

Many young boys are interested in playing with toys. The toy industries are making huge strides in adding embedded systems in the normal toys to make them more accommodative of the automotive aspects of automobiles. With a slight increase in cost, one can purchase a toy that has remote controlled features. This report seeks to analyze the construction of such toys and the methodology implemented to get the most efficient outcome. Arduino is a tool for making smart devices that can sense and control. It provides open source electronics as prototyping platforms. These platforms are based on their flexibility, ease of use with hardware and software. Infrared communication has been successfully implemented on television systems and it can be improvised in any other electro-mechanical system for remote communication. The infrared sensor in the car circuit senses inputs from the remote and the vehicle responds based on the code set output. The television, for instance, is a common example of the infrared communication. The mode of communication has been used for decades now and it is still considered an appropriate means of communication for the home entertainment industry. There are health and environmental factors taken into consideration when choosing the mode of communication especially for wireless communication techniques.

Arduino is an embedded language that is used in the development of code in native C language that are used to control hardware and robotic implementations. The Arduino is comprised of the software and hardware sections where the software forms part of the code in embedded C while the hardware is a microprocessor. The microprocessors come in various forms dependent on the size, memory space, and functionality. These microprocessors are fed with code and have sections for input and output. These are the sections that interact directly with hardware and as a result the hardware can be controlled using the code fed into the controller. There are several types of Arduino boards namely Arduino Uno, At-mega 328 & 1280, Mega 2560, Genuino zero and 101, and Arduino MKR1000. The company keeps generating more and more variants as the need increases. The programming language used in the system design and coding is the wiring – C libraries and it is implemented in an Arduino integrated development environment (IDE). There is a robotic implementation as an electronic machine is used to control a mechanical machine. The mechanical machine in this report is the car. It is remote controlled through sensing, use of intelligence and the energy. This project focusses on the Arduino Uno as the microcontroller board used. The microcontroller is powered either by a battery or using an AC to DC adapter. The good thing about Arduino projects is that the source code is open sources, therefore, there is so much reuse of pre-existing code in the project. One does not need to generate their own code to perform the common functions. The Arduino Uno is a basic type of microcontroller for Arduino projects as it supports only the basic features and has limited memory space. The difference in size could imply that the microcontroller lacks in memory space, number of input ports, and output ports. There are several parts of an Arduino Uno that are of key interest in this project namely:

• Digital input and output pins
• Analog input pins
• Memory feature of the Arduino Uno

The Arduino Uno is a product of the ATMEL microcontroller with the controller of type Atmega 328. It has up to 32 pins and operates on flash memory with read-while-write capabilities. It runs on a 1024 Byte EEPROM and has 23 General Purpose input & output lines. It is very efficient for use with small scale projects as it provides the full package without wasting too much memory. The analog pins are usually up to 5 pins with a voltage capacity of up to 5 volts. They allow for input just as the digital pins but they mainly interact with sensor components. The system has a parallax standard servomotor that controls the rotary actuators in the system. The aim of the servomotor is to control the angular position, speed, and accelerator of the truck used in the system. It operates such that the motor operates depending on the sensor input. The parallax RF transceiver is used to obtain inputs and send serial data wirelessly to and from a microcontroller and personal computer. These transmitters send signals that are needed and a receiver gets them. The signal is processed and the car complies with the outputs of the microcontroller which highly depends on the input signals. Alternatively, a parallax tact switch is used. It is a normally-open push button. To control a manual model of the car, about 4 push buttons are incorporated. There are many ways of performing the remote communication. Several projects in the past have been carried out using Bluetooth and others using wireless signals through antenna systems. This project focusses on the use of infrared wireless communication. This wireless communication method is frequently used by the television systems to switch channels and control the volume, brightness, contrast, or any other parameter. The project requires only a receiver mode as the car does not send out other signals. The infrared sensor in the car circuit senses inputs from the remote and the vehicle responds based on the code set output.

Infrared communication uses the infrared light signals. The signals operate between the remote-control gadget and the car or television being controlled. These light signals are invisible to the human eye but can be easily detected by another digital gadget. The infrared remote acts as the transmitter while the IR sensor is the receiver. The light signals are projected at a carrier frequency of 38 kHz. The ATMEL 328 in the Arduino Uno decodes the series of pulses and determines if the input is valid or not. When valid the input is actualized and an output is denoted by the car moving in a certain direction or having it stop. Wireless communication techniques can be used for short range or long range communication. The radio frequency type provides the Bluetooth, ZigBee, and the near-field communication (NFC) variants for the short-range communication. For longer ranges, antennas are used to been radio waves from one point to another. Wireless communication modes ensure contactless communication for up to a given length. The wireless communication is merited highly when it comes to security concerns. There are common functions used in Arduino to allow for input and display.

The methodology defines the stepwise approach in achieving the set objectives in a system design.

• Arduino Uno
• Connecting wires
• Sample vehicle or toy truck chassis
• Remote sensor (Simulated with a push button)
• Parallax standard servo motor
• Parallax RF transmitter
• Parallax RF receiver
• Battery and ground

1. The system was designed and proposed. When the proposal was accepted, the designer set out to work on the implementation. All the required components as listed in the system components section were obtained in a budget friendly way.
2. All the passive components were well placed on the breadboard. The connecting wires were made according to the circuit diagram as shown in the project proposal. The circuit diagram shows all the connections from the power to the microcontroller and to the ground.
3. The system designer launches the Arduino software and types in code that will run on the microcontroller to control the car. The remote sensor on the breadboard is connected to the analog pin on the microcontroller
4. After connecting all the components to the microcontroller. The microcontroller is connected to the Personal Computer and the Arduino code inofile is loaded to the Arduino Uno board. The system is powered, and the microcontroller starts up.
5. The remote was used to test different inputs as shown in the code if conditional segment. For different values the LEDs lit differently. In some circumstances, they lit in full, partially, or not at all. The results section clearly highlights the system design implementation and testing.
6. The design was taken for testing. Different inputs were fed into the sensor and different outputs were expected. The discussion section confirms if the tests were successful and what was not well captured in the project.

The following block diagram shows the connection of components and the flow of information as the components interact. The remote communicates with the IR receiver which is an IR sensor attached to the breadboard and connected as an analog input to the microcontroller.

1. Line 1: calls the header file IRremote() so as to use its global variables and key functions in the implementation of the remote-controlled car system.
2. Several pins are declared and initialized to act as the inputs. The function irrecv()is used to obtain the value sent to the infrared sensor or receptor.
3. The common void setup ()acts as a constructor that defines the pin modes for different digital pins and shows the status of each pin at the initial stage. Usually this pins are LED pins. They are usually initialized as LOW meaning they are turned off.
4. The void loop ()function holds the conditional statements that are highly dependent on the input obtained by the receptor. Several values are anticipated by the code designer and outputs are generated as a result.
5. The function digitalWrite ()is a default function in the Arduino IDE that instructs the LED pin to either light or turn off the LED. When the output is being generated the remote-controlled receptor is put on hold for a moment and when the output is displayed it is resumed using the resume () This ensures that the commands do not conflict.

The structure was designed as stipulated in the methodology and it was implemented.

• The breadboard connection of passive components and the microcontroller

Figure 1 The breadboard connection based on the circuit design of the system

• The finished product

Figure 2 connection embedded on the Truck Chassis for testing

Figure 3 Finished product showing the sensor part

The source code first initialized the code by including the IRremote header file. This header file has functions and variables that are useful in the rest of the code especially in obtaining input from the IR remote through the sensor. The working principle behind the entire concept of the project is the transmission and reception of an infrared beam that is invisible to the human eye. There are other communication modes such as radio frequency that are to an extent more efficient than the infrared communication. They cover longer ranges and communication is received a bit much faster. The IR receiver in the circuit connection picks up the commands sent by the remote and performs the required function. The IR remote acts as the transmitter. It sends out pulses of the infrared light through an LED on the front of the remote. The pulses are encoded in a manner that the IR receiver can interpret and turn into specific commands. The signal is limited in the coverage distance. It can only beam up to about thirty feet or lesser than that. Infrared is an optical control that requires a line of sight. The LED on the IR transmitter must be pointing at the IR receiver in order to work. Unfortunately, the signal cannot be beamed through a wall. Depending on the strength of the infrared signal being transmitted, when it is beamed under sunlight the range may be shortened.

As a result, it is very unsuitable to design remote controlled car or vehicle projects with the intention of controlling them over a long-range flight, outdoor racing, and other forms of activity that bypass the limited range and those that are within the line of sight. The radio frequency transceivers have better performance as compared to the infrared transceivers. Unfortunately, the RF transceivers are bulky and heavy. As a result, it makes it difficult for a manufacturer to come up with smaller toys. It is also more expensive than the IR remote control. The remote-control toys that use infrared are micro-sized. The RC toys for the young kids tend to use the infrared control as it eradicates the use of antenna on the vehicle controller. The IR remote is a header file included at the beginning of the code to provide the reuse of function for input and control. It sends and receives infrared signals with multiple protocols. It can be obtained from the Arduino portal for tutorial design or on the GitHub master page. Other alternatives simply use it for transmitting the wireless serial data to and from the embedded system on the truck chassis. Further work proposes the use of camera live view and the interface of the application and settings are set around the Wi-Fi. The remote gets additional buttons as the features of the toy car, being remote controlled, increase.

Further Studies

1. The system designer needs to ensure that there is exclusivity during the remote configuration and communication to a given truck. For instance, if two toy trucks are in the same range, a designer must configure the sensors and label them uniquely such that the remotes only control their own toy trucks and not those of others. This is termed as collision avoidance of the systems.
2. Similarly, the cost of manufacturer and production of the system should be taken into consideration to ensure that it is economically feasible and technically efficient by the time it becomes a product.

The project transforms the manual toys to automated toys. The project is based on the infrared sensors for reception. More and more devices are being automated in this digital era making life much more easy and interesting. Different kinds of remotes perform different functions and issue different commands as shown in the inputs at the Arduino code. The microcontroller integrates the entire system and control the input as well as the outputs. More can be done besides just controlling a vehicle. A vehicle can have add-ons controlled to do more than just move in the direction it is pointed to or to stop.

• A.V. Deshmuk, “Microcontrollers (Theory & Applications)”, WTMH, 2005.
• Sony SIRC infrared protocol, http://picprojects.org.uk/, February 2010.
• Study of several promising short range wireless communication technologies. Weifang Wang (IEEE explorer).