Nikhil Agnihotri

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,…

In the previous tutorial, we discussed the basics of the I2C protocol. In most of the embedded devices, either UART otherwise I2C is used for console messages. In this tutorial, we will discuss serial communication in Raspberry Pi using the I2C protocol. I2C in Raspberry Pi For serial communication over the I2C protocol, the Broadcom…

In the previous tutorial, we covered how to interface a NEO-6M GPS module with Raspberry Pi (RPi). The module communicates with RPi over the universal asynchronous receiver/transmitter or UART protocol.  The UART is the most common point-to-point data communication protocol. But, it’s not the only serial communication protocol. In embedded electronics, I2C and SPI protocols are…

In previous tutorials VHDL tutorial (#6), we built a circuit for D Morgan’s Theorems in VHDL and verified its output to prove D Morgan’s theorems. (If you are not following this VHDL tutorial series one by one, you are requested to go through all previous tutorials of these series before going ahead in this tutorial)…

In the previous tutorial, we learned how to interface a SIM900 GSM-GPRS modem with Raspberry Pi (RPi) and a desktop computer. We employed serial UART communication to “talk” with the SIM900 modem. By using bidirectional data communication with the modem via a standard UART interface, we were able to make/receive calls and send/receive SMS messages on RPi and…

The Global Positioning System (GPS) is the most widely used satellite navigation system around the world. It is one of the Global Navigation Satellite Systems (GNSS) that provides geolocation, time, and velocity information. GPS is operational since 1978 and globally available since 1994. The latest GPS receivers provide geolocation with an accuracy of 30 centimeters.…

In the previous tutorial, we learned how to interface a DHT-11 sensor with Arduino. DHT-11 is a digital sensor that comes integrated with an 8-bit microcontroller. This integrated microcontroller outputs humidity and temperature values in the form of a 40-bit digital data packet.  In the last tutorial, we read the data packet by polling one…

In the previous tutorial, we covered the AT commands that are supported by a SIM900 GSM-GPRS modem. We’ve already discussed how to interface a SIM900A GSM-GPRS modem with Raspberry Pi, Arduino, as well as other microcontrollers and desktop computers. Now, it’s time to use this modem to make and receive calls, and send and receive…

eSIMs are not only going to cater to M2M solutions. They are about to have a significant impact on the consumer segment as well. Apple has already incorporated eSIM is some of its latest models. Other consumer device manufacturers are also moving on to include eSIMs in their smartphones and wearable devices. GSMA has proposed…