AVR ISP SERIAL PROGRAMMER

This simple COM PORT based  AVR atmega Programmer will allow you to painlessly transfer hex programs to most ATMEL AVR microcontrollers

without sacrificing your budget and time. It is more reliable than most other simple AVR programmers available out

there and can be built in very short amount of time.

AVR programmer consists of in-circuit serial programmer (dongle) and small pcb with a DIP socket where you can fit

your microcontroller and have it quickly programmed.

You may also use this programmer as a stand alone in-circuit serial programmer that can be used to conveniently

program AVR microcontrollers without removing them from the target circuit.

Entire AVR programmer has been build with using common parts and fits in the case of the serial connector. The socket pcb has been created to fit a 28-DIP AVR ATmega8 microcontroller, but you can build a socket pcb for any other AVR microcontroller out there. This AVR programmer is compatible with a popular PonyProg software that shows you a status bar of the programming progress.

AVR In-Circuit Serial Programmer Schematic

Ensures that the chip is receiving exactly +5V voltage it ensures error free programming.

+5V voltage supply for AVR chip may be provided from external power supply or even better - directly from USB

Pony Prog :The Programming software

To be able to send hex file from your computer to AVR microcontroller you will need to download and install PonyProg2000. After the installation, the first thing you will need to do is configure PonyProg to work with our AVR Programmer. To do this go to "Setup" menu and select "Interface Setup". The following window will be shown and highlighted areas show you exactly which options should be selected.

In the next step select "AVR micro" and your microcontroller type that you will be programming (ex. ATmega8

At this point PonyProg configuration is complete and we can open hex program with which AVR microcontroller will be flashed. Go to "File" menu, select "Open Program (FLASH) File ...", and point to the hex file to open it up. You should see hex numbers as shown on the screen below. If you haven't connected AVR Programmer dongle to your computer's serial port yet, then now is the time. Make sure that AVR Programmer is physically connected to your AVR microcontroller through Socket PCB or through ICSP 6-PIN connector. Finally click on the highlighted icon "Write Program Memory (FLASH)", or go to "Command" menu and select "Write Program (FLASH)".

!! IF your Flash(.hex) file have special configuration bits Then you have to configure those bits manually.

Click on "Yes" button to confirm the programming.

Now sit tight, relax and watch the programming progress on the status bar. PonyProg will program AVR microcontroller and verify if the hex file was transferred without any errors. For your information this process shouldn't really take more than 10 to 30 seconds. This depends on the size of the program that you're trying to flash.

After programming is completed "Write successful" window will be shown letting you know that AVR microcontroller has been programmed, and is now ready to be used.

Programming The Security and Configration Fuse bit (if needed)

          First click on the sercurity and configration button in the tool bar,  a dilog box will apper as shown in the image blow.

To read the current security bit from the devive please click Read button in the securit and configration bits dialog box

now you are ready to change the configration bits
To caclulate these ceck box values accoring to your needs or to claculte by use hfuse and lfuse

just check and uncheck the boxes accoring to your setting and click write button.

Here is the "WORLDS SMALLEST MAGNETIC DATA STORAGE"

There will be a time when all the major technologies in the world will be in nanoscale. Recent developments have been undergone in daily used electronic gadgets like mobiles, computers, laptops and so on. As a part of this, a group of researchers from IBM and CFEL (Centre for free-electron Laser Science) have been successful in developing the world’s smallest magnetic data storage unit. The newly invented unit needs only 12 atoms for storing one bit. That is, 96 atoms for storing one byte. In a conventional memory storage unit a byte consists of half a billion atoms and hence this new technology will prove to be a breakthrough for producing the new generation of devices called “nanogadgets”.

This nano data storage unit was made by placing atom by atom by using a STM (scanning tunneling microscope) at IBM’s Almaden research centre in San Jose, California. First a regular pattern of iron atoms were constructed and then they were aligned in such a way that each row contains six atoms. The storage density of this nano structured memory unit is supposed to be a hundred times better than the currently used hard drives.

With the help of an STM data is written to the nano storage unit. The pairs of the atoms will be having two magnetic states representing zero and one. By using the STM the polarity of the atoms are changed to the desired value. For this purpose, an electromagnetic pulse is applied to the electrons from the STM. A weaker electronic pulse is used to read the data from the nano structure.

 In conventional hard drives and other data storage structures data is stored by ferromagnetism but here special form of magnetism called the anti ferromagnetism is used here to record data. As the materials are anti ferromagnetic, the atoms can be spaced more closely as the magnetic fields will not be interfering with each other and hence nano size can be achieved. Scientists say that this discovery will open new doors to quantum physics and smarter gadgets can be developed in the near future.

WIRELESS Main Voltage Tester

Description.

This circuit can be used to test whether mains voltage is present or not without having electric contact with mains line. The CMOS IC CD4033 is the heart of this circuit. The CD4033 consists of a 5 stage decade Johnson counter and an output decoder for converting the Johnson code to a 7 segment decoded output for driving 7 segment LED display. A 10cm long insulated copper wire connected to the clock pin (pin1) of the IC serves as the sensor. The sensor wire has to be placed in the vicinity of the mains wire to be tested. When there is no voltage in the mains line, no voltage will be induced in the sensor wire and the display will show a random digit. When there is voltage in the mains line, a small voltage will be induced in the sensor wire due to electromagnetic induction and this voltage is sufficient enough to clock the CMOS IC CD4033. Now the display will count from zero to nine and repeat.

Circuit diagram.

 

Notes.

• The circuit can be assembled on a Vero board.
• Use 9V PP3 battery for powering the circuit.
• Use a 10cm insulated wire as the sensor.
• The IC must be mounted on a holder.
• Switch S1 can be a miniature ON/OFF switch.

Testing a Diode with Multimeter

DESCRIPTION :-

Diodes are one of the components that can be tested very easily.Ordinary diodes as wells as Zener diodes can be checked by using a multimeter. While testing a diode the forward conducting mode and reverse blocking mode has to be tested separately.

Testing ordinary diode using a digital multimeter.

To check an ordinary silicon diode using a digital multimeter, put the multimeter selector switch in the diode check mode. Connect the positive lead of multimeter to the anode and negative lead to cathode of the diode. If multimeter displays a voltage between 0.6 to 0.7, we can assume that the diode is healthy. This is the test for checking the forward conduction mode of diode. The displayed value is actually the potential barrier of the silicon diode and its value ranges from 0.6 to 0.7 volts depending on the temperature.

Now connect the positive lead of multimeter to the cathode and negative lead to the anode. If the multimeter shows an infinite reading (over range), we can assume that the diode is healthy. This is the test for checking the reverse blocking mode of the diode.

For testing Germanium diodes, the procedure is same but the display will be between 0.25 to 0.3 V to indicate a healthy condition in the forward biased mode. The potential barrier for Germanium diode is between 0.25 and 0.3V.When reverse biased the multimeter will show an infinite reading (over range) to indicate healthy condition.

Testing ordinary diode using  analog multimeter.

To check an ordinary Silicon diode using an analogue multimeter, put the multimeter selector switch in a low resistance position (say 1K).Connect the positive lead of multimeter to anode of the diode and negative lead of multimeter to cathode of the diode. If meter shows a low resistance reading, we can assume that the diode is healthy. This is the test for checking forward biased mode of the diode.

Now put the multimeter selector switch in a high resistance position (say 100K).Connect the positive lead of multimeter to cathode of the diode and negative lead to anode of the diode. If the meter shows an infinite reading, we can assume that the diode is healthy. This is the test for checking the reverse blocking mode of the diode. The meter shows infinite or very high resistance reading because a reverse biased diode has a very high resistance (usually in the range of hundreds of K Ohms).

Testing Zener diode.

The forward characteristics of a Zener diode is similar to an ordinary diode.So the methods used for testing  forward conducting mode of  any ordinary diode is applicable to the Zener diode too.But in reverse mode, the reverse  breakdown voltage has great significance and it has to be specifically tested.For example a 5.3V Zener diode must start conducting only when the applied reverse voltage just exceeds 5.3V.The reverse  bias mode of Zener diode can be easily tested by using the circuit given below.The resistance R1 can be typically 100Ohms.The multimeter must be in voltage mode.Now slowly increase the output of variable power supply  and at the same time observe the voltage shown in the multimeter. The multimeter display increases along with the increase in power supply voltage until the breakdown voltage. Beyond that the multimeter reading stays put despite of the power supply voltage. This is because the Zener diode is now in breakdown region and the voltage across it will remain constant irrespective of the increase in supply voltage and this constant voltage will be equal to the breakdown voltage. If the reading of multimeter in this instant is equal to the breakdown voltage specified by the manufacturer, we can assume that the Zener diode is healthy.

While carrying out this test, remember not to exceed the input excitation voltage to a point that forces the Zener diode to dissipate more power than it can safely handle. Typically current through the diode should not be allowed to exceed more than 10mA.

Testing a SCR with Multimeter

Testing SCR using a multimeter.

A multimeter can be used to test SCRs quite effectively. The first procedure is to check the diode action between the gate and cathode terminals of the SCR. This test is just like what you have done in the case of testing a silicon diode (see testing a silicon diode).

Now put the multimeter selector switch in a high resistance position. Connect the positive lead of multimeter to the anode of SCR and negative lead to the cathode. The multimeter will show an open circuit. Now reverse the connections and the multimeter will again show an open circuit.

Then connect the anode and gate terminals of the SCR to the positive lead of multimeter and cathode to the negative lead. The multimeter will show a low resistance indicating the switch ON of SCR. Now carefully remove the gate terminal from the anode and again the multimeter will show a low resistance reading indicating the latching condition. Here the multimeter battery supplies the holding current for the triac. If all of the above tests are positive we can assume the SCR to be working fine.

Circuit for testing SCR.

This is another method for testing an SCR. Almost all types of SCR can be checked using this circuit. The circuit is just a simple arrangement for demonstrating the basic switching action of an SCR. Connect the SCR to the circuit as shown in diagram and switch S2 ON. The lamp must not glow. Now press the push button switch S1 ON and you can see the lamp glowing indicating the switch ON of SCR. The lamp will remain ON even if the push button S1 is released (indicates the latching).If the above checks are positive then we can conclude that the SCR is fine.

Testing a TRIAC with Multimeter

Testing TRIAC using a multimeter.

A multimeter can be used to test the health of a triac. First put the multimeter selector switch in a high resistance mode (say 100K), then connect the positive lead of multimeter to the MT1 terminal of triac and negative lead to the MT2 terminal of triac (there is no problem if you reverse the connection).The multimeter will show a high resistance reading (open circuit).Now put the selector switch to a low resistance mode, connect the MT1 and gate to positive lead and MT2 to negative lead. The multimeter will now show a low resistance reading (indicating the switch ON).If the above tests are positive then we can assume that the triac is healthy. Anyway this test is not applicable triacs that require high gate voltage and current for triggering.

Circuit for testing a TRIAC.

This is another approach for testing a triac. Almost all type of triacs can be tested using this circuit. This circuit is nothing but a simple arrangement to demonstrate the elementary action of a triac. Connect triac to the circuit as shown in circuit diagram and switch S2 ON. The lamp must not glow. Now press the push button switch S1.The lamp must glow indicating the switching ON of triac. When you release the push button, you can see the lamp extinguishing. If the above tests are positive you can assume that the triac is healthy.

Testing a Thermistor with Multimeter

Thermistors are of two types, NTC (negative temperature coefficient) and PTC (positive temperature coefficient types). As their name indicates the resistance of an NTC thermistor will decrease with temperature and the resistance of a PTC thermistor will increase with temperature. Both PTC as well as NTC thermistors can be roughly checked by using an analogue multimeter.

Keep the analogue multimeter in resistance mode. Connect the multimeter terminals to the thermistor leads. Polarity is not an issue here. Now heat the thermistor by moving your heated soldering iron tip to it. Now you can see the multimeter reading smoothly increases or decreases depending on whether the thermistor under test is PTC or NTC. This will happen only for a healthy thermistor.

For a faulty thermistor, following observations are possible.

• The change in reading will not be smooth or there will not be any change.
• For a short thermistor the meter reading will be always zero.
• For an open thermistor the meter reading will be always infinity.

This is only a rough test. For a perfect check up; you need some way to measure the temperature and the corresponding resistance reading must be according to the thermistor’s temperature-resistance characteristics provided by the manufacturer.