Nikhil Agnihotri

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…

eSIM is the upfront SIM technology that is deemed to be adopted globally for long-range and mobile M2M/IoT applications. The fundamental feature of eSIM technology is remote SIM provisioning. A complete eSIM ecosystem is all about subscription management solution. At present, both proprietary and GSMA-compliant subscription management solutions are under development. The proprietary systems are…

In the previous tutorial, we learned how to interface an LM35 temperature sensor with Arduino. LM35 is an analog sensor that can be interfaced with Arduino’s analog input pin.  In this tutorial, we’ll cover how to interface a DHT-11 sensor with Arduino. DHT-11 is a digital temperature and humidity sensor. It outputs a much more…

In the previous tutorial, we covered how to interface a SIM900A GSM-GPRS modem with Raspberry Pi, Arduino, and desktop computers. SIM900A can communicate data with the controlling device over the universal asynchronous receiver/transmitter (UART), I2C, or SPI protocol.  The modem is a piece of mobile equipment with an IMEI number that’s capable of all cellular…

In the previous tutorial, we learned how to use Raspberry Pi’s (RPi) serial hardware port for serial data communication over the universal asynchronous receiver/transmitter (UART) protocol. Most of the embedded devices have the UART port for exchanging console data. In fact, most of the sensor modules that are designed for peer communication with controllers/computers have the…

In the previous tutorial, we discussed the universal asynchronous receiver-transmitter (UART) protocol and voltage levels, covering USB-serial boards and other serial adaptors. We also learned how to find a serial port name on Linux, Windows, macOS, and Raspberry Pi (RPi). In this tutorial, we’ll learn how to use the Python Serial library to setup bidirectional…

In the previous tutorial, we discussed serial communication protocols available on Raspberry Pi. We discussed the terminology of data communication and defined the terms like ‘port’, ‘bus’, ‘interface’, ‘protocol’ and ‘standard’. We talked about UARTs on Raspberry Pi and how these UARTs are referenced by different serial Linux device names when they are accessed through…

IoT is the next development in modern life evolving through the present era of smartphones, tablets, and wearables. Connected cars, smart earphones, AI translators, personal assistance systems powered by augmented reality, vehicle tracking, AI-backed video surveillance, and many other embedded applications will become a part of our existence. These billions of “things” need internet connectivity…

In the previous tutorial, we learned how to generate analog output in the form of software PWM when using Raspberry Pi (RPi). We also showed how software PWM can be used to fade an LED.  The PWM output can also be used for other applications, such as for speed control of a DC motor or…

In the previous tutorial, we learned how to use digital input with Raspberry Pi. Raspberry Pi (RPi), as an embedded computer, is capable of digital input, digital output, pulse width modulation (PWM), and the implementation of several serial communication protocols (such as UART/USART, I2C, and SPI).  In this tutorial, we’ll cover analog output by using PWM with…

In the previous tutorial, we discussed how to use a digital output on Raspberry Pi. We designed a GUI-controlled LED driver, demonstrating how single-board computer features — like high-level language (HLL) such as Python — can control embedded applications.  Microcontroller-based embedded applications are typically programmed in low-level languages, such as in Assembly Language or embedded…

In the previous tutorial, we covered TTK menus, layout management in the Tk GUI toolkit, and mouse and keyboard events in Tkinter/TTK. We also discussed multi-threading in Python and created our own class of a threading package. This means we can implement our Raspberry Pi (RPi) codes exactly as if they are running on a…

Several consumer devices now involve temperature monitoring. For example, most of the air conditioners on the market feature climate control, where the AC continuously monitors the ambient temperature of a room and accordingly regulates the air conditioning. Even some digital clocks now have temperature monitors embedded in them. Many other consumer appliances also offer temperature…

In the previous tutorial, we learned how to display custom characters on a character LCD. Character LCD is the most commonly used display device in embedded systems and circuits.  Although character LCDs are from sophisticated, they provide a simple interface that’s easy to use and learn. They also convey useful information about operating conditions, warnings,…

In the previous tutorial, we discussed scrolling long text strings on a character LCD using Arduino. However, it’s also possible to display custom characters on the LCD. These custom characters are user-defined and are stored in Character Generator RAM (CGRAM) of the LCD module.  The different LCD modules have different Display Data RAM (DDRAM) and CGRAM, which…

In the previous tutorial, we discussed:  The functional blocks of a character LCD How character LCD works and is interfaced with a controller  How to display text on a character LCD In this tutorial, we will learn about scrolling long string of text on a character LCD, which can be tricky. A character LCD module has…

In the previous tutorial, we discussed multiplexing seven-segment displays (SSDs). Continuing with the display devices, in this tutorial, we will cover how to interface character LCD when using Arduino. Character LCDs are the most common display devices used in embedded systems. These low-cost LCDs are widely used in industrial and consumer applications. Display devices in embedded systems…

In the previous tutorial, we discussed interfacing RGB LEDs with Arduino. In this tutorial, you’ll learn how to interface seven-segment display (SSD) when using Arduino.  When interfacing with any kind of display device, Arduino and other controllers use digital output or serial communication. Driving SSDs by Arduino is as simple as driving an LED on it. The seven-segment…

In the previous tutorial, we discussed analog input when using Arduino. So far, we have covered four out of the five ways that controllers can interface and interact with other electronic components and devices. This includes digital output, digital input, analog output, and analog input.  In this tutorial, we discuss how to interface RGB LEDs using Arduino.…