· For programming any microcontroller, the general approach is to declare and define functions in the same file in which the main logic of the program [generally in main () function] is written. · This approach is universally adopted because it is easy for the reader to understand the whole program as the functions used…
While dealing with controllers we are dealing with digital signals but real world is analog. In real world all natural quantities like temperature, pressure, light intensity etc. are analog. If we have to deal with such quantities using embedded systems, we have to convert these analog quantities which can be understood and proceed by digital signal. Devices used for this purpose is known as ADC. Special ICs such as ADC0804, ADC0808, ADC0809, Serial ADC MAX1112 etc. are handy for this. Nowadays, many controllers are having inbuilt ADC. LPC2148 of ARM7 family is one of the widely used controller and it also has multichannel ADC inbuilt. In this article, we will understand how to use inbuilt ADC of LPC2148.
We can control the speed of the single phase DC Motor with ease by using microcontroller and proper driving mechanism.In industries mostly coil based analog variable frequency drive is used. Because of this type of variable frequency drive there are problem rising like over current, short circuit, over voltage, under voltage, under frequency which results in unwanted tripping of the devices.We can replace this coil based analog variable frequency type with microcontroller based speed controlling mechanism. Because of this type of speed controlling, we can accurately control the speed of DC motor in operation. In addition to this, this type of controlling comparatively cheaper, reliable and accurate .It requires less maintenance and it is more convenient in use.Aim of this project is to control speed of dc motor using commands sent from mobile phone. As speed of dc motor is dependent on duration of input voltage, by changing the duration we can control the speedof the single phase dcmotor.
Fig. 1: Digital Clock Using Inbuilt RTC of LPC2148 Prototype Real Time Clock (RTC) is used to store Time and Date in the system even when the system is not in operation. This is the system used in many devices including Laptop. Mobile phones, Tablet, Digital Cameras etc. RTC is inbuilt part of any electronics device. DS1307…
In embedded systems, it is often required to communicate with other peripherals like GSM, GPS and even PC. Various protocols like I2C, SPI, BLUETOOTH, WI-FI etc. are used for this purpose. Serial communication using RS232 protocol is the most common and widely used protocol in embedded systems. In this section, we will explain basics of serial communication and how to communicate with PC using RS232 protocol.LPC 2148 controller from Philips of ARM7 family is used in this section
Fig. 2: General Keypad MatrixSwitch is the most widely used input device. When a switch is pressed either low or high signal is given to controller depending upon the circuit designing. This approach requires one pin for a single switch. With increasing requirement of input devices, more numbers of controller pins are required which may not be available all the time. For example, to enter value from 0 to 15, we need 16 pins of controller to be interfaced with switches. To reduce number of required pins, we can arrange keys in matrix form.Matrix keypad is one of the widely used input devices. Some of the application includes Mobile keypad, Telephone dial pad, calculator, ATM etc. Keypad provides an easy way to allow user to provide input to any system. In this article, we will explain how to interface 4×4 matrix keypad with LPC2148. The pressed key will be displayed on LCD.
LCD stands for Liquid Crystal Display used to display numbers, strings and special characters as per the application. It is one of the widely used modules in embedded system. Almost all embedded product requires LCD.Advantage of LCD over LEDs is its ability to display any number, alphabet, special characters and user defined symbol (at extra effort for programming) without increasing number of pins required to be connected with controller. Interfacing of LCD with LPC2148 differs little bit compared to interfacing with 8051 or AVR which operates on 5V. LCD operates on 5V but LPC 2148 operates on 3.3V so we have to take care of this fact for the controller pins which has to be connected with LCD.
A buzzer or beeper is an audio signal generator type device, which may be mechanical, electromechanical or piezoelectric depending upon the operating principle of the device. Buzzers are widely used in alarm devices, timers and confirmation of user input such as a mouse click or keystroke.In embedded systems, buzzer is widely used to notify various events such as interrupt generation, end of any process or as an alarming on emergency situation such as detection of fire, exceeding radiation in nuclear reactor plant etc.
India is an agricultural country & farming is a basic occupation in our country. Since today farmers are watering the plants everyday but this is the project whichhelps the farmers & in farming field for watering without any problem because here there is watering system is made. In this system the thirsty plant gives message to the farmer that it needs water and then we can water the plants. Nowadays, people have nursery at their home and some people have hobby of gardening. So at these places also this watering system is very useful for people. Many plants need more water & some plants need less water depending on the level of moisture in the soil.People use this system in their daily life & this system is called botanical system.
Line follower is an autonomous robot which follows either black line in white are or white line in black area. Robot must be able to detect particular line and keep following it. For special situations such as cross overs where robot can have more than one path which can be followed, predefined path must be followed by the robot. In the following section, we will discuss the line follower robot which follows black line in white area and take right turn whenever cross overs or Y shaped turn arrives.However with some minor suitable changes, users can make robot for other possibilities also.
ADCs acts as a bridge between the ANALOG real world and digital world of controllers. ADC converts analog voltage into a digital number which can be understood and proceed by controller. Let us understand this with an example. LPC 2148 operates on 3.3V supply. If we use 10 bit ADC, 3.3V correspondences to 2^10=1023. Half…