Electrical and Electronics Circuit: June 2018

Saturday 30 June 2018

Scientists fine-tune carbon nanotubes for flexible, fingertip-wearable terahertz imagers

Researchers have developed flexible terahertz imagers based on chemically 'tunable' carbon nanotube materials. The findings expand the scope of terahertz applications to include wrap-around, wearable technologies as well as large-area photonic devices.

Sintering atomically thin materials with ceramics now possible

For the first time, researchers have created a nanocomposite of ceramics and a two-dimensional material, opening the door for new designs of nanocomposites with such applications as solid-state batteries, thermoelectrics, varistors, catalysts, chemical sensors and much more.

The culprit of some GaN defects could be nitrogen

As silicon-based semiconductors reach performance limits, gallium nitride is becoming the next go-to material for several technologies. Holding GaN back, however, is its high numbers of defects. Better understanding how GaN defects form at the atomic level could improve the performance of the devices made using this material. Researchers have taken a significant step by examining and determining six core configurations of the GaN lattice.

Friday 29 June 2018

BNAs improve performance of Li-ion batteries

Recent research has investigated the effect of hierarchical Bi2MoO6 nanosheet arrays on the performance of Li-ion batteries (LIBs) and found that it improves the cycle stability and capacity and is expected to be used in portable electronic devices in the future.

Simple logic for nanofluidic computing simulated

Invigorating the idea of computers based on fluids instead of silicon, researchers have shown how computational logic operations could be performed in a liquid medium by simulating the trapping of ions (charged atoms) in graphene (a sheet of carbon atoms) floating in saline solution. The scheme might also be used in applications such as water filtration, energy storage or sensor technology.

Arduino Interrupts Tutorial

In this tutorial, I will talk about Arduino Interrupts and how can we use Interrupts in Arduino to handle various real time events and multi-tasking.

Normal Execution of Arduino Code

All the Arduino Projects that we have implemented so far are pretty straightforward i.e. the code written in void setup { } function will initialize all the pins, variables and other important functions (like Serial or LCD) and the code written in the void loop { } function is executed over-and-over again.

We have implemented this method in all our Arduino projects; right from Blinking LEDs to Controlling a Robotic Arm with an Android Phone.

This mechanism is well and good if you just want your Arduino to execute a series of instructions sequentially like this simple Blinking of LEDs.

In this code, the setup function will run only once when the Arduino is powered ON and will initialize the Digital I/O Pin 12 as an OUTPUT pin.

Arduino will now enter into the loop function, where it turns ON the LED, waits for a second, turns OFF the LED, waits for a second and repeats the process.

Button Example

Now, consider the same situation with interfacing a button with Arduino. In this simple sketch, I am interfacing a push button with Arduino in order to toggle the status of the LED i.e. push once for turning the LED ON and push again for turning it OFF.

Arduino Interrupts Tutorial Circuit Diagram

This is Polling!

In this scenario, the Arduino (or the ATmega328p Microcontroller, to be specific) keeps on checking for the state of the button in the loop function. This method of checking whether a device or pins needs service from the processor (the microcontroller) is called as Polling.

The main problem with this approach is that the controller is continuously engaged in an activity (checking the status of the button in this case) and cannot perform any other tasks. Here comes the concept of Interrupts to the rescue.

What is an Interrupt?

Interrupt is a mechanism through which the processor is informed to stop the current execution of instructions, execute a special event or process and then return back to the original execution.

Interrupt Occurred

The main advantage of Interrupts in Arduino (or any microcontroller or processor on that note) is that the processor doesn’t have to continuously poll with the devices whether they need any attention. The device itself “Interrupts” the processor whenever a service is required until which, the processor can perform some other tasks.

If you take the button example once again, originally, the controller was continuously checking for the status of the button. But introducing the concept of Interrupts into this situation, the controller can do whatever it wants (I mean anything other than checking for the status of the button, as per your code) and whenever the button is pressed, it will automatically stop the current execution and puts its full attention to the button press event.

Upon interrupt, I said that the processor executes a special process and this special process is nothing but a set of instructions called Interrupt Service Routine. The structure of an Interrupt Service Routine or ISR is similar to that of any user defined void function.

Interrupts in Arduino

Arduino has three different sources of Interrupts:

Timer Interrupts
External Interrupts
Pin-Change Interrupts

NOTE: Timer Interrupts in Arduino, as the name suggests, are caused by the Arduino Timers while the Pin-Change Interrupts can be enabled when a change in state of a group of Pins is detected.

Discussion on Arduino Timers, Timer Interrupts and Pin-Change Interrupts is a little bit out of the scope of this tutorial so I will continue with the External Interrupts.

External Interrupts

As the name suggest, the External Interrupts in Arduino are due to external events i.e. a change in state of any of the External Interrupt Pins. For example, when you receive a pulse from Water Flow Sensor like in this project “ARDUINO WATER FLOW SENSOR TUTORIAL” or when simply when you press a button.

Arduino UNO has two external interrupt pins namely INT0 and INT1. Internally, INT0 is mapped to Digital I/O pin 2 and INT1 is mapped to Digital I/O pin 3.

How to Enable Interrupts on Arduino?

There is a special function called attachInterrupt() in Arduino, using which you configure the External Interrupts.

The syntax of attachInterrupt() function is as follows.

attachInterrupt(digitalPinToInterrupt(pin), ISR, mode);

There are two other syntaxes of this function but this one is recommended by the Arduino reference guide.

Let us now understand the arguments of this function.

digitalPinToInterrupt(pin)” is to specify the Interrupt pin number.
ISR is the Interrupt Service Routine function call.
mode is to indicate when to trigger the interrupt.
- CHANGE: Trigger the Interrupt when there is a change in the pin value.
- RISING: Trigger the Interrupt when the pin value rises from LOW to HIGH.
- FALLING: Trigger the Interrupt when the pin value falls from HIGH to LOW.
- LOW: Trigger the Interrupt when the pin value becomes LOW.

Button Example with Interrupt

Now, let us revisit the earlier button example by attaching Interrupt to the button pin. The following is the new code with button interrupt.

In the above code, the button is connected to Pin 2 (INT0) of Arduino and an interrupt is attached with respect to this pin on an event of CHANGE in the value of the button pin and triggering an ISR named button_ISR.

An important note about this code is even though Interrupt is implemented here, it is still not the best executions possible. The following is a more suitable code with interrupt and it even considers the button debounce.

The important points to note from above implementation are:

Variable used in the ISR must be declared as Volatile.
The ISR should be as minimum as possible.
No delay () in ISR.

The post Arduino Interrupts Tutorial appeared first on Electronics Hub.

Wednesday 27 June 2018

Top 20 Best RGB LED Strip Light Kits: 2018 Reviews

With the advancement in technology, and change in lifestyle, everybody wants to enjoy the cinematic experience at home. For them, the best choice is to go with the RGB LED Strip Lights.

LED strips are becoming more popular now-a-days due to the energy-saving option, vibrant colours (red-green-blue), brightness and flexible to work at both homes and offices. They take up the design to next level by hanging in gaps, small electronic appliances like TV, refrigerator, PC, furniture’s and wall hangings.

This amazing strips do come with programmable options, remote control, smart app navigation features for the convenience of users to handle wirelessly at a distance and perform hassle-free functioning.

However, for choosing LED strip lights there is no clear-cut idea as there’re plenty of options available in the market. So we’ve come with Buying Guide to help you in deciding the right one as per the requirements.

Our team of experts have done 48 hours of intense research on RGB LED strip lights by interacting with customers, and reviewing the products. Finally, we’ve come with the Top 20 Best RGB LED Strip Lights that helps you to make an intimated choice.

RGB LED Strip Light Kits	Check the Price
Tingkam 5050 SMD RGB LED Flexible Strip Light Kit	Check the Price
TBI RGB LED Strip Lights Kit	Check the Price
Music LED Strip Lights 6.6FT/2M 5V USB Powered Light Strip Kit	Check the Price
LEDMO LED Strip Lights	Check the Price
Pangton Villa USB LED TV Backlight Kit	Check the Price
HitLights Weatherproof RGB 150 LED Light Strip Kit	Check the Price
KorJo RGB LED Strip Light	Check the Price
MINGER DreamColor LED Strip Lights	Check the Price
MINGER RGB LED Strip Lights	Check the Price
MINGER One-Line Car Interior Lights	Check the Price
LEDdess Full Kit RGB LED Strip Computer Lighting via Magnet	Check the Price
TINGKAM 5050 SMD RGB Flexible LED Strip Light Kit	Check the Price
ALITOVE WS2812B Individually Addressable LED Strip Light	Check the Price
RXment RGB LED Strip Lights	Check the Price
LEN RGB Light Strip Complete Kit	Check the Price
Magic Light Wi-Fi LED Light Strip	Check the Price
NexLux Non-waterproof LED Light Strip	Check the Price
Targher RGB LED Strip Lights	Check the Price
Nexlux LED Strip Lights, Wi-Fi Wireless	Check the Price
Sunnest 2 Reels 12V 32.8ft Waterproof Flexible LED Strip Light Kit	Check the Price

1. Tingkam 5050 SMD RGB LED Flexible Strip Light Kit

Are you looking for the best strip lights that spreads vibrant colors, then Tingkam RGB LED strip light is for you. It is one of the finest quality LED strip light that is made with durable materials and environmentally protected.

Moreover, Tingkam brand maintains high standards of performance and safety. Hence we’ve given top priority in the list of top 20 best RGB LED strip lights. Its design is very simple and can be used for home interior designs, weddings, parties, events, gardening and so many possibilities at an affordable price.

What is included?

RF control box
US power adapter
44-key remote controller
5050 RGB LED strip light (5-meter)

Using 16.4feet strip tape and 150 LED’s, it generates 15 different dynamic colors that can be changed according to your mood. There is an option for you to cut 3LED’s for shaping into patterns and fix to groceries, cupboards and other decorative items.

You can control the light settings, using light controller and to function this wonderful device, it should be connected to a power supply of 12V/2.5A.

The compact and flexible PCB strips are of 3meters apart for making different designs and styles. It has got a IP44 waterproof rating in which the strips are protected from rain and water. And the device is backed with 12-months of manufacturing warranty. If you find anything serious or damaged part, then go to the nearest authorized service center for replacement.

Wrapping up, this Tingkam RGB LED strip light is a decent quality product that delivers outstanding performance. It has all the features required for a strip light and saves electricity bills. It is widely used in exhibitions, shopping malls, parties, festivals, hotels, restaurants, pubs, cinema theaters, etc.

The only thing we don’t like about the product is that it can spread the brightness to an extent where you may feel discomfort and also there’re batteries included in the kit to provide the remote. Apart from these, it’s totally good to buy for homes.

Things we love

Low power consumption.
Waterproof protection.
Best price LED strip light.
High intensity and reliable strip lights
Simply plug and play type device.
Environmentally protected LED strip.
12 months of manufacturing warranty.

Things we hate

No batteries provided for the remote.
You don’t find dimmable option.