Embedded Systems & Robotics BasicsSubmitted to : Submitted by:Mr. Ritesh Saraswat (guide) Sachin kr. JainMs. Seema Sharma (co-guide) Subhash choudhary Vivek kr. gupta
Embedded SystemsA embedded system is a microprocessoror microcontroller based electronic deviceused for specific task. It is designed to perform operationswhich minimize (or even completelyavoid) need of human control.
Types of embedded systems1. Real time embedded system (a) Soft real time embedded system (b) Hard real time embedded system2. Non real time embedded system
Applications of embedded system• Pen drives• Hard disk• Mouse• Calculators, electronics welding machine• Cell phones• Security system• Alarm system• Digital camera• Environment monitoring systems
Microcontroller A Microcontroller is a programmable digital processor withnecessary peripherals. Both microcontrollers andmicroprocessors are complex sequential digital circuits meant tocarry out job according to the program / instructions. Sometimesanalog input/output interface makes a part of microcontrollercircuit of mixed mode (both analog and digital nature).Types: (a) RISC microcontroller (b) CISC microcontroller we have used ATmega16 in training
Features of Modern Microcontrollers• Built‐in Monitor Program• Built‐in Program Memory• Interrupts• Analog I/O• Serial I/O• Facility to Interface External Memory• Timers
Features of ATMEGA16• It is a 40 pin Ic• Advanced RISC Architecture• 16K Bytes of In‐System Self‐Programmable Flash• 512 Bytes EEPROM• 1K Byte Internal SRAM• 32 Programmable I/O Lines• In‐System Programming by On‐chip Boot Program
ProgrammingProgrammer basically consists of two parts: • Software (to open .hex file on your computer) • Hardware (to connect microcontroller Hardware depends on the communication port you are using onthe computer (Serial, Parallel or USB).There are 2 good software which support this hardware and cancommunicate with micro controller using this circuit. They are,• Pony Prog• At‐Prog
Code Vision AVR (CVAVR) Atmel Microcontrollers are very famous as they are very easy to use. First of all we need an easy IDE (Integrated Development Environment) for developing code. We used CVAVR (Code Vision AVR) It has limitation of code size. It works on computers with Windows platform that is Windows XP & Vista.
I/O functions RegisterInput Output functions are set by Three Registers foreach PORT.DDRX ‐‐‐‐> Sets whether a pin is Input or Output of Port X.PORTX ‐‐‐> Sets the Output Value of Port X.PINX ‐‐‐‐‐> Reads the Value of Port X.
• Since Timer works independently of CPU it can be used to measure time accurately.• As we know a timer is an 8 bit register that keeps on increasing its value, so one of the basic conditions is the situation when timer register OVERFLOWS i.e. it has counted up to its maximum value (255 for 8 BIT timers) and rolled back to 0. In this situation timer can issue an interrupt and we must write an Interrupt Service Routine (ISR) to handle the event.
Timers in Atmega16 Atmega 16 has following timers:- Timer 0 - It is an 8-bit timer and for this pin no. 4 (PB3) is used. Timer 1 - It is 16 –bit timer, It has two types OC1A(8-bit) at pin no 19 and OC1B(8-bit) at pin no 18. Timer 2 - It is also an 8-bit timer and pin no 21 (OC2) is used for this.
Modes of TimersThere are four modes of timers, are as: Normal mode CTC mode Fast PWM mode Phase correct PWM mode
SPI: Serial Peripheral Interface• Serial Peripheral Interface Bus or SPI bus is a synchronous serial data link used to communicate between two or more microcontroller and devices supporting SPI mode data transfer.• In this mode, devices communicate in master/slave mode where the master device initiates the dataframe. Multiple slave devices are allowed with individual slave select (chip select) lines.
SPI: Serial Peripheral Interface• SPI communication protocol consists of following pins:- – MOSI : Master Out Slave In (Tx for Master and Rx for Slave) – MISO : Master In Slave Out (Rx for Master Tx for Slave) – SCK : Serial Clock (Clock line) – SS : Slave Select (To select Slave chip) (if given 0 device acts as slave)
SPI: Serial Peripheral InterfaceMOSI:-Channel where the master sends thedata to the slave and the slave receives it. MISO:-Channel where the slave sends the data and the master receives it.
SPI: Serial Peripheral InterfaceSCK:-Clock is send by the master.SS:-Slave select when the master wants tosend data to a particular slave it makes its SSpin low, sends the data and then again makes ithigh.
UARTIn the UART protocol, the transmitter and the receiverdo not share a clock signal. That is, a clock signal doesnot emanate from one UART transmitter to the otherUART receiver. Due to this reason the protocol is saidto be asynchronous
Serial Port of Computer• Serial Port is used for communication between the uC and the computer.• A serial port has 9 pins.• For laptop, most probably there wont be a serial port. In such case, we use a USB to serial Converter.• For transmitting one byte of data, the serial port will transmit 8 bits as one bit at a time.
Serial Port of Computer• Pin 3 is the Transmit (TX) pin, pin 2 is the Receive (RX) pin and pin 5 is Ground pin.• Other pins are used for controlling data communication in case of a modem.• For the purpose of data transmission, only the pins 3 and 5 are required.
MotorsDevice used to convert electrical energy into mechanicalenergy is called a motor.Some Motors used in embedded systems and roboticsare described as below:i. Stepper motorsii. Servo motorsiii. Geared DC Motors
MotorsWe used Gear motors during Training.• Gear motors are motors with an integrated gearbox.• Geared motors have a variety of applications. Some of its uses are as in wheelchairs, stair wheels etc.
SensorsA sensor is a device that measures a physical quantityand converts it into a signal which can be read by anobserver or by an instrument.We can use different types of sensor like,1. Temperature sensor: We use LM35 IC as temperature sensor.
Sensors2. Light Dependent Resistor (LDR): LDR is basically a resistor whose resistance varies with intensity of light. More intensity less its resistance (i.e, in black it offers high resistance and in white it offers less resistance).
SensorsTSOP:TSOP 1738 Sensor is a digital IR Sensor; It is logic 1(+5V) when IR below a threshold is falling on it andlogic 0 (0V) when it receives IR above threshold.It does not respond to any stray IR, it only responds to IR falling on it at a pulse rate of 38 KHz.
SensorsIR-Sensor:In this we use three main components IR-LED, Photodiode & LM358 IC.From any “non black body” obstacle IR reflects andfalls on photo diode.Hence Photo diode become forward bias, and it turnon the IC LM358 that gives the output.