EXASUB

  • Capacitor Time Constant=RC or Charging Time

    In this video, the time constant for the capacitor is calculated.

    Time Constant is denoted by the symbol tau τ

    τ = R*C

    Where R = value of the resistor

    and C = value of capacitor

  • Capacitor ESR

    A real capacitor has a series resistance which is due to the imperfect manufacturing process and also because of the cost regulations.

    lower ESR = Better Capcitor = Higher Cost

    A lower ESR capacitor is better but the manufacturing cost will also be on the higher side. So, there is a compromise made between ESR and cost.

  • Arm Based Microcontrollers

    At the time of writing this article ARM-based microcontroller means the microcontroller which uses a 32-bit RISC processor design from ARM holdings.

    Presently ARM Cortex-M series of processor cores are being integrated into microcontrollers.

    The ARM-Cortex M family comprises the following processors.

    • Cortex-M0
    • Cortex-M0+
    • Cortex-M1
    • Cortex-M3
    • Cortex-M4
    • Cortex-M7
    • Cortex-M23
    • Cortex-M33
    • Cortex-M35P
    • Cortex-M55

    The Cortex-M4 / M7 / M33 / M35P / M55 cores also have a hardware-based floating-point unit. The addition of a Floating point unit adds the capabilities for digital signal processing.

    To see a list of ARM-based microcontrollers.

    Keil.com has a great list that has almost all the major microcontrollers out in the market and is supported by the Keil IDE.

    https://www.keil.com/dd/chips//arm.htm

  • Compile AVR Code in Raspberry Pi

    I have recorded a video showing the steps to compile AVR code.

    In this video, you will see how to compile AVR led blinking code for the atmega32 microcontroller is being compiled using AVR-GCC in raspberry pi 3 b+.

    Step 1. : Create a file and put your avr c code in that file. Save that file with a “.c” extension

    Step 2. : Run the following commands one by one

    avr-gcc -g -0s -mmcu=atmega32 -c led.c

    avr-gcc -g -mmcu=atmega32 -o led.elf led.o

    avr-objcopy -j .text -j .data -o ihex led.elf led.hex

    Step 3. : The step 2 will create a hex file. which can be uploaded to the microcontroller with the help of a programmer.

  • How to install AVR-GCC Compiler in raspberry pi

    In this video, you will see that how avr compiler can be installed in raspberry pi model 3 b+.

    For steps on how to install avrdude in raspberry pi you can go here.

    http://www.exasub.com/component/integrated-circuit/microcontroller/avr/using-usbasp-v2-0-avr-programmer-with-raspberry-pi-3/

    AVR compiler and avrdude together on raspberry pi make it a development environment for embedded systems involving Avr microcontroller.

  • Using USBASP V2.0 AVR Programmer with Raspberry Pi 3

    Raspberry pi or Rpi can be used for programming certain AVR microcontrollers. I have made a video showing you the steps.

    Step 1: you have to install AVRDUDE

    sudo apt-get install avrdude -y

    Step 2: You can check if the avrdude is installed properly or not using

    avrdude

    step 3: connect your USBASP v2.0 to your microcontroller 

    avrdude -c usbasp -p m32

    Microcontroller Programmed:

    Atmega32, atmega32a, Atmega16, Atmega16a,

  • Capacitor

    A physical device capable of storing energy in the form of the electric field in the dielectric medium when voltage is applied across it.

    In the following video, you will find explanations to:

    1. capacitor
    2. capacitance
    3. Series and Parallel connection of capacitor
    4. Impedance
    5. Reactance

  • How to calculate the value of a resistor from colour codes

    To calculate the value of a resistor from colour codes.

    Then, First, you have to locate the Tolerance band.
    The tolerance band mostly in most of the resistors is made from either gold colour or silver colour.

    Then you need to look at the next band which tells you the multiplier.

    Then you need to look at the opposite end of the resistor and note down the colour in order till the multiplier.

    The first band from the left gives us the first digit.
    The next band gives the next digit.

    Resistor color coding chart

  • Resistor

    A resistor is an electronic component that offers resistance in the flow of current. The practical resistor has a slight shift in its values from the ideal counterparts.

    Not all the values of the resistor are available in the market. There is a certain number that is chosen and is readily available. If a particular value is to be achieved then a combination made from the selected resistors is to be used.

    An ideal resistor follows Ohm’s law.

    A practical resistor changes its value if the surrounding temperature, pressure and changes in mechanical dimension etc. Though there are very nominal changes yet they differentiate the ideal resistor from the practical counterpart.

    The resistors value is generally marked on the surface. If the resistor is big, standard values along with manufacturing company seal are also printed on top of it.

    For very small resistors; either colour bands or some code is written on top of it. As the size goes on decreasing the surface area becomes small and reaches a point where it is not feasible to print anything that can be visible to the naked eye. Then the values are written beside the component.

    10 Kilo Ohm Through Hole Type Resistor
    SMD Resistor with value code written on it
    SMD resistor with a reference to value is printed beside it.

    There are two types of resistors.

    1. Fixed Value resitors
    2. Variable Value Resistors

    It is important to consider the power dissipation of a resistor. Since resistor obstructs the flow of current. The obstruction causes a buildup of energy which needs to dissipate. If this energy is not released then it will burn the resistor or permanently change its resistance values. So resistors use heat to dissipate the energy.

    for example:
    Let’s consider an 8-ohm resistor that resists the flow of current.


    A voltage source of 9V has connected across. The 8-ohm resistor drops the voltage from 8V to 0V. Blocking a significant portion of voltage that is 8V.
    and Let’s say the current flowing in the circuit is one Ampere.
    So the resistor needs to dissipate 8W of energy.
    Now you need to select a resistor that can dissipate more than 8W of energy. and the next best option is to use a resistor of 10 watts.

  • How to add a new .h header file in STM32 Cube IDE

    1. Click on [arrow] besides Core in your project explorer
    2. Right Click on “Inc” folder and point your mouse at the “NEW” menu item.
    3. Select “header file” option
    4. A new Header file dialog box will appear
    5. Fill in the name of the header file in “Header file” with a dot h extension
    6. Click on finish
    7. Now open your main.c file and add your custom header file after USER CODE BEGIN Incudes

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