Nikhil Agnihotri

The COVID-19 pandemic has severely affected the lives of millions across the world. It has caused a significant increase in the awareness of health and better hygiene. As a result, the electronics industry has experienced a rapid demand for touchless devices and appliances, such as contactless sanitizer or soap dispensers and automatic doors. For this…

As electronic miniaturization has been an all-time goal of chip manufacturers, motherboard-based computer/electronic systems have been eventually replaced by System-on-Chip (SoC) and Package-on-Package (PoP) ICs. Complex computer systems are now condensed to smartphones and other handheld devices. These sophisticated electronic devices and gadgets have an SoC at their heart which manages complete computing and control.…

Proximity sensors are used to detect something approaching near. These sensors are useful in many applications like collision avoidance, obstacle detection, path following, touchless sensing, motion detection, and object detection. There are different types of proximity sensors like optical, ultrasonic, capacitive, inductive, and magnetic. The capacitive, inductive, and magnetic proximity sensors are used in specific…

Light sensors or photosensors, which are designed to measure light intensity, are one of the most commonly used sensors in electronic applications. Light intensity is one of the seven base physical quantities. The measurement of light intensity is useful in many consumer, industrial, and security applications. What is a light sensor? A light sensor is…

Light sensors are widely used in electronic applications. The most common one used is a photoresistor or light-dependent resistor. Despite a long response time, this sensor is inexpensive and useful in several applications. A photoresistor consists of a zigzag track of photo-sensitive semiconductors. It offers pure resistance although this is dependent on the ambient light.…

A digital clock is a commonly used electronic gadget. A digital clock keeps track of time and displays the current time through an output device. The users can set or reset the clock using buttons. Electronic clocks are built using microcontrollers and may or may not use a real-time clock. Here, a digital clock is…

Smart homes need wireless connectivity, and Z-wave has emerged as the ultimate solution for home automation. The Z-wave protocol is a wireless, radio frequency protocol designed primarily for smart home networks. All the existing wireless communication protocols had one or the other problem. Bluetooth and Zigbee often shortfall of range while Wi-Fi poses its own…

Data communication over analog signals is a common process. In automation, the data is communicated to and from controllers with several different process instruments. Quality is important as the controllers and smart instruments must communicate over long distances.  Additionally, the data communication between a device and a controller must be dictated by a protocol (i.e.…

In the previous tutorial, we learned how to interface a buzzer with Arduino. A buzzer is an audio signaling output device. Embedded systems are built by interfacing several input and output devices with a controller or computer.  In this tutorial, we’ll interface an input device — specifically, a TTP229 capacitive touch keypad — with Arduino.…

In the previous tutorials, we learned about serial communication using the SPI (serial peripheral interface) and seven-segment multiplexing using the MAX7219 IC. We’ve also covered digital I/O, analog input, PWM (pulse width modulation), and all of the serial communication protocols commonly used by embedded controllers (the UART, I2C, and SPI).  This completes the basic coverage of the Arduino platform. With the above-mentioned skillsets, we…

In the previous tutorial, we learned how to interface a seven-segment display with Arduino. A seven-segment display is comprised of a unit of eight LEDs and seven of which are bar-shape and one is a dot. These display units are ideal for displaying numbers or letters. For example, they’re often used as a display unit…

A buzzer or beeper is an audio signaling device. It generates sound in a frequency range of 1 to 7 kHz as an audio indication. In this frequency range, the hearing threshold is maximum. Therefore, the sound of a buzzer is so piercing that it is noticeable even in a highly noisy environment. The buzzers/beepers…

In the previous tutorial, we learned how to interface an ADXL345 accelerometer with Arduino by using the I2C bus. UART, I2C, and SPI are the most common serial communication protocols used in embedded electronics.  UART, a universal asynchronous receiver-transmitter, is used for full-duplex serial communication with a single device. The I2C, an inter-integrated circuit, is a master-slave,…

In the previous tutorial, we covered the I2C bus in Arduino. We also learned about using the wire library to communicate with the Inter-integrated circuit or I2C devices using Arduino boards.  The I2C bus is commonly used by digital sensors. When using this interface, hundreds of slave devices can be connected over just two wires. Each device —…

In the previous tutorial, we learned about serial communication in Arduino using the universal asynchronous receiver-transmitter (UART). We also discussed how Arduino can talk with a computer system using the UART protocol.  The UART is a dedicated circuit that implements serial communication according to its protocol. Arduino boards have one or more UART/USART. These UART/USART interfaces are available through…

In previous tutorials, we’ve covered serial communication using the UART and software serial in Arduino. The universal asynchronous receiver/transmitter (UART), I2C, and SPI are the most commonly used serial interfaces in embedded systems.  UART is useful for full-duplex serial communication with a single device over two wires. The I2C or two-wire interface (TWI) is used for half-duplex…

In the previous tutorial, we discussed interfacing with the ADXL345 accelerometer sensor with Raspberry Pi using the I2C interface. UART, I2C, and SPI are the most common serial communication interfaces used in embedded systems. UART is used for point-to-point full-duplex asynchronous serial communication between two devices. I2C is used for synchronous serial communication among multiple…

In the previous tutorial, we discussed synchronous serial communication in Raspberry Pi using I2C protocol. In this tutorial, we will use the I2C interface of Raspberry Pi to communicate with a digital sensor. The digital sensor that we will talk with is the ADXL345 accelerometer. ADXL345 is a small, ultra-low power, 3-axis accelerometer sensor that…

Inertial sensors are used to detect linear and rotational motion of an object. There are two types of inertial sensors – accelerometers that detect linear acceleration and gyroscopes that detect rotational motion. Accelerometers and gyros are widely used in several applications, including aerospace, military, automotive, mobile phones, and consumer electronics. For example, in mobile phones,…

Inertial sensors are used to transduce inertial force into measurable electrical signals to measure acceleration, inclination, and vibration of an object. Micromachining technology has made it possible to produce MEMS (Micro Electromechanical System) inertial sensors using single-crystal silicon sensor elements. These micron-sized sensors meet all major system design drivers like low-cost, high performance, high precision,…