Keypad 4x4 || TinkerCAD Circuits Input Component

 A 16-button keypad with digits 0-9, letters A-D, and the * and # symbols. It is used for user input.

Description:

This device consists of 16 momentary switches arranged in a grid pattern.

How It Works:

Patterns of conductive material are printed onto layers of plastic, and a small domed membrane can be squeezed or pressed to allow contact between the two surfaces.

Connect It:

This device has eight wire leads that correspond to the rows and columns of switches inside. Connect each pin to its own digital pin on the Arduino.

How It Is Used:

Click the device’s buttons during simulation to press the switches.

Get Started:

Details about component in a circuit’s working [No Get Started Circuit]

More About Keypad 4x4

To add a Keypad 4x4 in Tinkercad, search for "Keypad 4x4" in the component library, drag it onto your breadboard, and connect its terminals with wires to other components in your circuit. You can then click on the Keypad 4x4 to set its name for easy identification. 

The 4x4 Keypad is a compact input device used in digital electronics, most commonly utilizing a Membrane Keypad design. This type is constructed from flexible sheets (membranes) with conductive traces (typically silver or carbon) forming a 4×4 matrix of momentary switches. The key feature of its construction is the matrix wiring which allows 16 keys to be interfaced using only 8 connection pins (4 rows and 4 columns), significantly saving microcontroller I/O ports. Key specifications for these low-power devices typically include a Maximum Voltage Rating of 24 VDC to 35 VDC, a very low Maximum Current Rating of 30 mA to 100 mA (milliamperes), and an Operating Temperature Range of approximately 0∘C to 50∘C (degrees Celsius). The durability is high, with a Life Expectancy often rated at over 1 million key presses.

Instructables – Connecting a 4 X 4 Membrane Keypad to an Arduino Website Title: Instructables

Website Page URL: https://www.instructables.com/Connecting-a-4-x-4-Membrane-Keypad-to-an-Arduino/ 

URL recommended for (Reason): A practical, step-by-step tutorial with clear pin-to-pin wiring instructions, including the modified Arduino code needed to get the 4x4 keypad working using the standard Keypad library.

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FactoryForward – 4×4 Matrix Keypad – Principle and Interfacing with Arduino Website Title: FactoryForward

Website Page URL: https://www.factoryforward.com/4x4-matrix-keypad-principle-interfacing-arduino/ 

URL recommended for (Reason): Detailed explanation of the keypad's working principle and scanning logic (how a microcontroller identifies the pressed key by checking rows and columns), along with the Arduino implementation.

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ElectronicWings – 4x4 Keypad Interfacing With Arduino UNO Website Title: ElectronicWings

Website Page URL: https://www.electronicwings.com/arduino/4x4-keypad-interfacing-with-arduino-uno 

URL recommended for (Reason): Provides the keypad library setup, complete Arduino code, and a discussion on different interfacing techniques, including a complex single-wire method for pin-saving.

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Adafruit Learning System – Matrix Keypad Overview Website Title: Adafruit Learning System

Website Page URL: https://learn.adafruit.com/matrix-keypad/overview 

URL recommended for (Reason): Excellent concise overview of the matrix layout (4 rows, 4 columns, 8 pins) and how it saves microcontroller pins, including links to resources for Arduino and CircuitPython.

Note: Autodesk® and TinkerCAD® are trademarks of their respective company

TinkerCAD Circuits Platform related Interesting Links:

TinkerCAD Circuits Reference Handbook eBook: About Page 

Quickly Master Electronics with the TinkerCAD Circuits Reference Handbook 

…till next post, bye-bye & take care.

C Interview Questions & Answers || Freshers Level || Set - II

 Question: What is C Language? 

Answer: C is a general-purpose and procedural language. The C programming language offers low-level access to system memory. Any program written using C must be run via a C compiler to transform it into an executable code for any computer to run.

Question: What is a token? 

Answer: A token can be described as the smallest unit required for creating a C program. Every punctuation and word in a C program can be called a token. A compiler will segment a C program into various tokens before proceeding to the different stages of a compilation process.

Question: Why is C called a mid-level programming language? 

Answer: C is called a mid-level language because it combines the characteristics of low-level and high-level languages. It is machine-independent like a high-level language, even though it can support pointer arithmetic like a low-level language. Programs written using the C language are converted into assembly code.

Question: What is the use of printf() and scanf() functions? 

Answer: The scanf() and printf() functions are useful for inputs and outputs in the C programming languages. These are in-built library functions defined in the header file called stdio.h.

Question: Why is the static variable used in C? 

Answer: The static variable in the C programming language is utilized for the following purposes:

• It is useful for retaining the value of multiple function calls.

• Its wide scope makes it accessible anywhere in the C program.

• It is treated as a common value, shared by all methods.

• It is initialized a single time in the memory heap to minimize memory usage.

Question: What is a built-in function in C? 

Answer: The C compiler creates inline code for built-in functions during compile time. Calling a built-in function can remove the runtime call to the function having the exact name in the dynamic library.

Question: What is recursion in C? 

Answer: Recursion involves making a function call itself. This valuable technique is useful for breaking complicated programs into simple ones.

Question: What is the difference between global int and static int declaration? 

Answer: The difference stems from where they can be declared. Global variables are always required to be declared outside the primary function. Static variables can be declared inside as well as outside the primary function.

Question: What is a pointer in C? 

Answer: Pointers in C are variables that store the memory address of other variables in the form of their value.

Question: How is const char* p different from char const* p? 

Answer: Const char*p denotes a constant character. Char*const p refers to a constant pointing toward a character.

Question: How are macros in the C programming language different from functions? 

Answer: The differences include:

• Code Length: Macros can increase code length, while functions cannot affect the code length.

• Processing: Macros need to be preprocessed, while functions need to be compiled.

• Execution Speed: Macros can help increase the execution speed, while function execution speed is somewhat lower.

• Substitution/Control: Before compilation, the macro value replaces the macro name, while transfer of control will occur during the function call.

• Error Checking: Macros won’t consider errors during compile time, while functions will check all errors during compile time.

…till next post, bye-bye & take care.

Gas Sensor || TinkerCAD Circuits Input Component

 A Winsen gas sensor used to detect gas leaks like carbon monoxide, alcohol, or methane. It is used for gas detection.

Description:

This sensor detects particles of a particular substance in the air.

How It Works:

This device detects the presence of a gas in an environment by measuring the electrical properties of the air.

Connect It:

This device has six wire leads. Power the heater by connecting +5V to either H1 or H2, and ground to the other. The resistance between A and B changes with the amount of gas detected. Connect one side of your detection circuit to A1 or A2, and the other to B1 or B2.

How It Is Used:

Select the device during simulation to show a cloud representing gas concentration. Slide the target to change the simulated gas level.

Get Started:

Select the device during simulation to show a cloud representing gas concentration. Slide the target to change the simulated gas level.

More About Gas Sensor

To add a Gas Sensor in Tinkercad, search for "Gas Sensor" in the component library, drag it onto your breadboard, and connect its terminals with wires to other components in your circuit. You can then click on the Gas Sensor to set its name for easy identification. 

Gas sensors are critical safety and environmental monitoring components, with the main types being Semiconductor/Metal Oxide (MOS), Electrochemical, and Non-Dispersive Infrared (NDIR). A popular example, the MOS type (like the MQ series), uses a tin dioxide (SnO2​) sensing layer and an internal heater coil (typically Nickel-Chromium alloy) to operate, drawing a power rating (heating consumption) of under 800 mW (milliwatts).General specifications often include a Circuit Voltage (VC​) of 5V (volts), a Heating Voltage (VH​) of 5V, and a corresponding Heating Current (IH​) up to 120 mA (milliamperes). The sensors' detection range—their working range—is measured in parts-per-million (ppm), with common ranges like 10 to 10,000 ppm for gases such as Methane (CH4​), Carbon Monoxide (CO), or LPG, indicating the volume ratio of the gas in the air.

Newark Electronics – Ultimate Guide to Gas Sensor Technologies Website Title: Newark Electronics 

Website Page URL: https://www.newark.com/decoding-gas-sensors-ultimate-guide-to-cutting-edge-gas-sensors-technologies-sg  

URL recommended for (Reason): A comprehensive overview of various gas-sensing technologies, including principles of operation (LEL, ppm, volume %), advantages, disadvantages, and the impact of environmental factors like temperature and humidity.

Asahi Kasei Microdevices (AKM) – Gas Sensors Types and Mechanism 

Website Title: Asahi Kasei Microdevices (AKM) 

Website Page URL: https://www.akm.com/global/en/products/co2-sensor/tutorial/types-mechanism/  

URL recommended for (Reason): Provides a focused, technical comparison of the NDIR, Semiconductor, and Electrochemical methods, detailing the underlying principle, precision, and application for each type of gas sensor.

Circuit Digest – A Comprehensive Guide to Gas Sensors 

Website Title: Circuit Digest 

Website Page URL: https://circuitdigest.medium.com/a-comprehensive-guide-to-gas-sensors-types-construction-and-applications-72fc5e59b74a   

URL recommended for (Reason): Offers a detailed breakdown of multiple sensor types (including PID, Catalytic, and Thermal Conductivity) along with the construction and working principle of common MQ-series (semiconductor) gas sensors.

Instructables – Interfacing Gas Sensor With Arduino 

Website Title: Instructables 

Website Page URL: https://www.instructables.com/Interfacing-Gas-Senslr-With-Arduino/  

URL recommended for (Reason): A practical, step-by-step tutorial on interfacing a standard MQ-series gas sensor with an Arduino, including the circuit diagram, components list, and the necessary code.

Note: Autodesk® and TinkerCAD® are trademarks of their respective company

TinkerCAD Circuits Platform related Interesting Links:

TinkerCAD Circuits Reference Handbook eBook: About Page 

Quickly Master Electronics with the TinkerCAD Circuits Reference Handbook 

…till next post, bye-bye & take care.