Roland Pelayo | Microcontroller Tutorials

Roland Pelayo

I started TMM back in 2015. I’m a firmware and embedded systems engineer with over ten years of experience designing and developing electronic and microcontroller-based products. Over the years, I’ve worked on a wide range of projects, including medical devices, access control and security systems, automation, robotics, wireless communication modules, IoT systems, imaging and sensor instruments, and educational training tools. I’ve built systems using platforms such as PIC, AVR, ESP32, STM32, nRF52, and Raspberry Pi, and I regularly work with protocols like RS485/OSDP, CAN, TCP/IP, Wiegand, and a variety of sensor and communication interfaces. I also develop full-stack solutions for embedded projects, combining firmware, hardware, and web-based dashboards when needed. If there’s a topic you’d like me to write about, or if you need consultation or hands-on development for electronics, embedded, or firmware projects, I’m always open to working on new ideas and collaborations. You can reach me anytime through the contact page.

How to Use the MQ-3 Alcohol Sensor

March 15, 2018 Arduino Tutorial

The MQ-3 alcohol sensor is useful for projects that tests levels of alcohol, benzine, hexane or LPG in the air but it is most popularly used as a breathalyzer (breath analyzer) for someone who drank beer, wine or other liquor. Learn how to use this gas sensor in this tutorial.

How to Use L298N Motor Driver

March 14, 2018 Arduino Tutorial, PIC Tutorial

You can drive an LED on or off using a microcontroller like Arduino or PIC. There’s no problem there because the 20 mA or so current from the pins is enough. You can’t drive loads that require much more current like a motor. This is where the L298N motor controller …

STM32 Nucleo Serial Communication

March 13, 2018 STM32 Tutorial

Debugging through the serial port is one of the ways to find errors in your code. In this tutorial, I'll show you how to add serial communication function to your STM32 Nucleo board.

Input and Output with STM32 Nucleo

March 13, 2018 STM32 Tutorial

We managed to blink an LED in the previous tutorial. This time, still featuring the STM32F1 Nucleo, we will add a button that will control the attached LED and a simple clap switch.

Blink a LED with STM32 Nucleo

March 10, 2018 STM32 Tutorial

On the previous tutorial, we managed to create our first program with the STM32 Nucleo board. Now we will dig deeper on the pinout and other functionalities of the board.

Getting Started with STM32 Nucleo and Mbed

March 9, 2018 STM32 Tutorial

The STM32 Nucleo boards by ST pack a lot more power than an Arduino UNO and have headers aligned the same way with the latter which makes it compatible with Arduino shields.

How to Interface a Thermistor

February 28, 2018 Arduino Tutorial

A thermistor is a special resistor whose resistance varies with temperature. Learn how to interface a thermistor with a microcontroller in this tutorial.

How to Use a Web Cam with Raspberry Pi

February 22, 2018 Raspberry Pi Tutorial

The Raspberry Pi comes with a camera connector on board. But if you don't want to buy the official camera and use a web camera instead, you can! I'll show you how to display a video from the webcam on a web server hosted by a Raspberry Pi

Setting up a Raspberry Pi Zero Web Server

February 22, 2018 Raspberry Pi Tutorial

I finally got my hands on a Raspberry Pi Zero W and started the usual tinkering. For those unaware, this smaller version of the Raspberry Pi packs a 1 GHz CPU and 512 MB of RAM. But what excites me the most is the WiFI and Bluetooth connectivity that comes …

How to Use LCD without Potentiometer

February 15, 2018 General

Maybe you’ve used an HD4480-based LCD before (pictured) and you know that it requires a potentiometer for adjusting contrast. Is there a way to remove this potentiometer completely?