Analog-to-Digital Converters (ADCs) are used in almost every embedded system where a microcontroller needs to work with real-world signals such as voltage, temperature, current, or sensor data. Because of this, ADC interview questions are very common in embedded systems and firmware interviews. In this article, we will cover ADC interview questions and answers from basic […]
ADC Interview Questions and Answers: Basic to Advanced Read More »
Have you ever written REG |= BIT and assumed it was a safe way to set a bit? It certainly looks like a single operation. However, on an ARM Cortex-M processor, the CPU actually performs it in three steps: read, modify, and write. If an interrupt happens between these steps and updates the same register,
Understanding Atomic Read-Modify-Write in ARM Cortex-M Read More »
During the development of optical communication firmware for smart meters, a strange field issue was reported: “Communication randomly drops. Works perfectly on the bench. Fails in the field.” To investigate the issue, I swapped cables, verified baud rates, and analyzed logic analyzer captures frame by frame. Everything appeared correct until I noticed that the optical
When UART Talks to Itself: The Optical Probe Loopback Bug Nobody Expects Read More »
In embedded firmware development, configuration is often controlled through compiler macros passed from the build system. This keeps the codebase flexible and allows easy customization for different products or hardware variants. In this blog post, we will explore how a macro can introduce a subtle bug, often referred to as a C macro override bug
C Macro Override Bug: When #define Breaks Build System Configuration Read More »
When working with C or C++ in embedded systems and firmware development, the ability to Detect Rising and Falling Edge of a Bit in C/C++ is essential. This technique is widely used when developing firmware for microcontrollers such as STM32, NXP, and TI to monitor digital signals, status registers, and hardware events reliably. In embedded
How to Detect Rising and Falling Edge of a Bit in C/C++ Read More »
When working with C or C++, particularly in embedded systems and firmware development, the ability to detect bit changes in C/C++ is essential. Because instead of writing: bool flag1; bool flag2; bool flag3; bool flag4; bool flag5; bool flag6; In embedded systems, we often store multiple related status flags inside a single variable. Generally, we
How to Detect Bit Changes in C/C++ Using the XOR Operator and Bit Masking Read More »
In this tutorial, you will learn how to interface a DC motor with Arduino using a motor driver IC (L293D). DC motors are widely used in embedded systems for motion control applications such as robots, conveyor belts, automatic doors, and small automation projects. Many beginners try to connect a DC motor directly to the GPIO
How to Interface a DC Motor with Arduino | Speed & Direction Control Read More »
The L293D is a 16-pin dual H-bridge motor driver integrated circuit used to control DC motors and stepper motors with low-power control signals from a microcontroller. It acts as a bridge between a microcontroller and your motors. Since microcontrollers operate on low voltage and cannot supply enough current to run a motor directly, the L293D
L293D Motor Driver IC: Pinout, Applications, and Circuits Read More »
Blinking an LED is usually the first program written by a beginner on any microcontroller. It is simple, easy to understand, and helps confirm that the board, clock, and GPIO configuration are working correctly. But once you move beyond this basic step and want to blink multiple LEDs at different speeds on STM32, things are
Blink Multiple LEDs at Different Speeds on STM32 Read More »
In the previous blog post, we learned how to control a relay using a push button and an Arduino. Now, let’s build another practical Arduino project using a push button and a piezo buzzer. In this tutorial, we will program the Arduino to buzz when a button is pressed. You will also learn how to
Arduino Button Piezo Buzzer Read More »