this program generates the template code for delay for AVR microcontrollers.The input given is the cycles or Time/sec or the clock frequency.After the entering these details the press the GO button and the code is generated which can be copied or saved.The copied or saved code can be used in the AVR STUDIO to program the microcontroller.
click here to download the the AVR delay calculator
Final Year Electronic Projects
It is usually the norm of students in the field of electrical, electronics, telecommunication, computer or communication of most universities and colleges to complete a final year project. Each must synthesize the theory and experimental work they learned during the first two to three years in order to complete the project. Under the supervision of their faculty supervisor, they must research, design, execute, document, and then present their work to the supervising committee.
A list of suitable topics will be offered by the university, from which preferred topics may be selected. Students sometimes will also have the opportunity to propose topics of their own devising, subject to approval for suitability.
Some of the projects which students may want to consider and get some ideas from are listed below. It usually involves the use of a microcontroller or a microprocessor in these projects. A lot of applications and ideas can be modified and build once they are familiar with circuit theory and operation.
Among the projects that one can consider is the utility metering projects which will become a norm in the near future. Hands-on of microcontroller projects will enable one to familiarise himself with the assembly language, C language and other tools that are used in the project.
Some of the final year electronic projects that one can get some ideas from are listed below.
Final Year Electronic Projects - Metering Project
Electronic meters compared to traditional mechanical solutions in use offer several additional advantages to the utility market. The metering utilities that can be replaced are gas, water and electricity meters.
Biometrics Digital Signal Processing Project
Biometrics is the technology used to analyze biological data. Its most recent application is in the area of security where the biological data of a person is used for personal identification and authentication before the person is allowed to proceed to enter a building or do any business transactions.
Bluetooth Technology
Bluetooth technology is a radio frequency short range communications technology that was created with the intention of replacing wired cables that are used to connect various portable and fixed devices. Get some reference design for your final year electronic projects here.
USB2.0 Card Reader Design Project
This project provides a reference USB2.0 Card Reader design with schematics and source codes for Compactflash, Memory Stick, Memory Stick Duo, Magic Gate, Secure Digital, MultimediaCard and SmartMedia.
X10 Home Automation Project
This project discusses the implementation of X-10 on a PIC microcontroller to create a home controller that can both send and receive X-10 signals.
Sensorless Brushless DC Motor Control Project
This project provides the application notes on the control of 3 phase sensor less brushless DC Motor.
Lighting Networking System Project
This project provides the application notes on the networking control of lighting devices using Digitally Addressable Lighting Interface Standard.
Zigbee Wireless Project
This project provides the application notes on the free frequency band wireless networking using Zigbee Standard.
The following are some engineering free magazine available to cater for your various engineering needs :
EE Times
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Electronic Design
Electronic Design's on-going objective is to observe and report the latest breakthroughs in EOEM technology. By providing this information Electronic Design has been the strategic partner of system designers and suppliers for the past 50 years, helping to bring them together so that they can deliver more competitive products to market faster.
Embedded System
Embedded Systems Design is a magazine for engineers, programmers and electronics hobbyists who are into using microcontroller and embedded microprocessor-based systems in their design.
This magazine provides best practices and peer guidance for Senior Systems Designers and their teams. These are the key designers responsible for defining systems, selecting the critical hardware and software components, building the systems, and integrating the hardware and firmware designs. This systems design magazine highlights the significant design methodologies, strategies and new products engineers need to gain a competitive advantage.
Electronic Products
Electronic Products reports on important developments in products and product technology. Its editorial serves as a key information source for engineers and managers.
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Test and Measurement
Test & Measurement World is the leading publication for engineers involved in electronics test, measurement, and inspection.
Test & Measurement World provides practical content and industry updates for engineers and engineering managers who are involved in using and buying equipment, software and services for test, measurement, inspection, and quality control during development, design and manufacturing or field service. 11 issues per year.
This I2C tutorial shows you how the I2C protocol works at the physical bit level. It only discusses single master mode (a single controlling device) as this is the most common use for I2C in a small system.
I²C (pronounced I-squared-C) created by Philips Semiconductors and commonly written as 'I2C' stands for Inter-Integrated Circuit and allows communication of data between I2C devices over two wires. It sends information serially using one line for data (SDA) and one for clock (SCL).
The phillips I2C protocol defines the concept of master and slave devices. A master device is simply the device that is in charge of the bus at the present time and this device controls the clock and generates START and STOP signals. Slaves simply listen to the bus and act on controls and data that they are sent.
The master can send data to a slave or receive data from a slave - slaves do not transfer data between themselves.
Multi master operation is a more complex use of I2C that lets you have different controlling devices on the same bus. You only need to use this mode if you have more than one microcontroller on the bus (and you want either of them to be the bus master).
Multi master operation involves arbitration of the bus (where a master has to fight to get control of the bus) and clock synchronisation (each may a use a different clock e.g. because of separate crystal clocks for each micro).
Note: Multi master is not covered in this I2C tutorial as the more common use of I2C is to use a single bus master to control peripheral devices e.g. serial memory, ADC, RTC etc.
The I2C interface uses two bi-directional lines meaning that any device could drive either line. In a single master system the master device drives the clock most of the time - the master is in charge of the clock but slaves can influence it to slow it down (See Slow Peripherals below).
The two wires must be driven as open collector/drain outputs and must be pulled high using one resistor each - this implements a 'wired AND function' - any device pulling the wire low causes all devices to see a low logic value - for high logic value all devices must stop driving the wire.
Note : If you use I2C you can not put any other (non I2C) devices on the bus as both lines are used as clock at some point (generation of START and STOP bits toggles the data line). So you can not do something clever such as keeping the clock line inactive and use the data line as a button press detector (to save pins).
You will often will find devices that you realise are I2C compatible but they are labelled as using a '2 wire interface'. The manufacturer is avoiding paying royalties by not using the words 'I2C'!
There are two wires (three if you include ground!) :
SDA : Serial Data
SCL : Serial Clock
I2C Tutorial : Typical SDA and SCL signals
Standard clock speeds are 100kHz and 10kHz but the standard lets you use clock speeds from zero to 100kHz and a fast mode is also available (400kHz - Fast-mode). An even higher speed (3.4MHz - High-speed mode) for more demanding applications - The mid range PIC won't be up this mode yet!
Note that the low-speed mode has been omitted (10kHz) as the standard now specifies the basic system operating from 0 to 100kHz.
A slow slave device may need to stop the bus while it gathers data or services an interrupt etc. It can do this while holding the clock line (SCL) low forcing the master into the wait state. The master must then wait until SCL is released before proceeding.
A basic Master to slave read or write sequence for I2C follows the following order:
Note: You can use 7 bit or 10 bit addresses.
The sequence 5 and 6 can be repeated so that a multibyte block can be read or written.
I2C Tutorial : Instruction sequence data from master to slave
A master device sends the sequence S ADDR W and then waits for an acknowledge bit (A) from the slave which the slave will only generate if its internal address matches the value sent by the master. If this happens then the master sends DATA and waits for acknowledge (A) from the slave. The master completes the byte transfer by generating a stop bit (P) (or repeated start).
I2C Tutorial : Instruction sequence data from slave to master
A similar process happens when a master reads from the slave but in this case, instead of W, R is sent. After the data is transmitted from the slave to the master the master sends the acknowledge (A). If instead the master does not want any more data it must send a not-acknowledge which indicates to the slave that it should release the bus. This lets the master send the STOP or repeated START signal.
Each device you use on the I2C bus must have a unique address. For some devices e.g. serial memory you can set the lower address bits using input pins on the device others have a fixed internal address setting e.g. a real time clock DS1307. You can put several memory devices on the same IC bus by using a different address for each.
Note: The maximum number of devices is limited by the number of available addresses and by the total bus capacitance (maximum 400pF).
The general call address is a reserved address which when output by the bus master should address all devices which should respond with an acknowledge.Its value is 0000000 (7 bits) and written by the master 0000000W. If a device does not need data from the general call it does not need to respond to it.
0000 000 1 START byte - for slow micros without I2C h/w
0000 001 X CBUS address - a different bus protocol
0000 010 X Reserved for different bus format
0000 011 X Reserved for future purposes
0000 1XX X Hs-mode master code
1111 1XX X Reserved for future purposes
1111 0XX X 10-bit slave addressing
Most of these are not that useful for PIC microcontrollers except perhaps the START byte and 10 bit addressing.
START (S) and STOP (P) bits are unique signals that can be generated on the bus but only by a bus master.
Reception of a START bit by an I2C slave device resets its internal bus logic. This can be done at any time so you can force a restart if anything goes wrong even in the middle of communication.
START and STOP bits are defined as rising or falling edges on the data line while the clock line is kept high.
START condition (S)
SCL = 1, SDA falling edge
STOP condition (P)
SCL = 1, SDA rising edge
The following diagram shows the above information graphically - these are the signals you would see on the I2C bus.
I2C Tutorial : START (S) and STOP (P) bits.
Note : In a single master system the only difference between a slave and a master is the master's ability to generate START and STOP bits. Both slave and master can control SDA and SCL.
This seems like a confusing term at first as you ask yourself why bother with it as it is functionally identical to the sequence :
S ADDR (R/W) DATA A P
The only difference is that for a repeated start you can repeat the sequence starting from the stop bit (replacing the stop bit with another start bit).
S ADDR (R/W) DATA A Sr ADDR (R/W) DATA A P
and you can do this indefinitely.
Note: Reception of both S or Sr force any I2C device reset its internal bus logic so sending S or Sr is really resetting all the bus devices. This can be done at any time - it is a forced reset.
The main reason that the Sr bit exists is in a multi master configuration where the current bus master does not want to release its mastership. Using the repeated start keeps the bus busy so that no other master can grab the bus.
Because of this when used in a Single master configuration it is just a curiosity.
All data blocks are composed of 8 bits. The initial block has 7 address bits followed by a direction bit (Read or Write). Following blocks have 8 data bits. Acknowledge bits are squeezed in between each block.
Each data byte is transmitted MSB first including the address byte.
To allow START and STOP bit generation by the master the data line (SDA) must not be changed while the clock (SCL) is high - it can only be changed when the clock is low.
The acknowledge bit (generated by the receiving device) indicates to the transmitter that the the data transfer was ok. Note that the clock pulse for the acknowledge bit is always created by the bus master.
The acknowledge data bit is generated by either the master or slave depending on the data direction. For the master writing to a slave (W) the acknowledge is generated by the slave. For the master receiving (R) data from a slave the master generates the acknowledge bit.
Acknowledge
0 volts
Not acknowledge
High volts
In this case the slave generates the acknowledge signal.
When a not-acknowledge is received by the bus master the transfer has failed and the master must generate a STOP or repeated START to abort the sequence.
In this case the master generates the acknowledge signal.
Normally the master will generate an acknowledge after it has received data but to indicate to the slave that no more data is required on the last byte transfer the master must generate a 'not-acknowledge'. This indicates to the slave that it should stop sending data. The master can then generate the STOP bit (or repeated START).
To use the I2C mode in the 16F88 the SDA and SCL pins must be initialised as inputs (TRIS bit = 1) so that an open drain effect is created. By setting them as inputs they are not driving the wires and an external pull up resistor will pull the signals high.
The 16F88 fully implements all slave functions except general call.
The general call function does not really matter as it is quite specialised commanding all devices on the bus to use some data.
A low output is generated by driving the signal line low and changing the pin direction to an output. A high output is generated by changing the pin direction to an input so that the external resistor pulls the signal high.
In slave mode this action is done for you by the SSP module (the outputs of the register at SDA and SCL are driven low automatically - regardless of the state of the register value).
Basically there is very limited master mode functionality.
There are two elements that are provided:
There are two interrupts that activate on reception of either a START or STOP condition. These two interrupts are only useful in a multi master mode system where it is necessary for the non-master device to detect the start and stop conditions. So for a single master system they are of no use at all!
Note When the SSP module is active SDA and SCL output are always set at zero regardless of the state of the register values. So all you have to do is control the port direction.
In master mode (16F88) SDA and SCL must be controlled using software.
It does it all for you!
Note if you want a chip with full master and slave mode operation look for the MSSP module in a PIC chip e.g. 16F877A - then you won't need more software - just enough to drive the module.
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Electronics Design Software (free or sharew)
FPGA, VHDL stuff
