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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.

Using RESTful APIs with ESP32

ESP32 NodeMCU-32S

With its WiFi capabilities, the ESP32 can connect to API services and acquire useful (and sometimes useless) information from the web. Here’s a quick tutorial on how to connect to RESTful APIs using ESP32.

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Getting Started with Blue Pill and STM32Cube

Arduino is easy to use but that's at the expense of numerous features, the most glaring of them is speed. Hence you would rarely see an Arduino in an embedded, industrial setting. ARM Cortex-M microcontrollers are low-cost, energy-efficient 32-bit devices with up to 2 DMIPS/MHz. They are the microcontroller of …

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Arduino State Machine Tutorial

Arduino State Machine Diagram

A finite state machine (FSM) is a theoretical machine that only has one action or state at a time. The machine may go from one state to another if there are inputs (or one input) that triggers the state change. In this article, I will guide you on how to …

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ESP8266 SPIFFs | File System for NodeMCU

ESP8266 NodeMCU SPIFFS

SPIFFS or Serial Peripheral Interface Flash File System is a system that utilizes extra flash memory on the ESP8266 and ESP32 for storing files. It’s so named because the user reads, writes or deletes files in the memory using the serial interface. In this article, I will show you how …

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How to Use MQ-4 Methane Gas Sensor

MQ-4 methane sensor breakout board

The MQ-4 is one of many gas sensors ready to be interfaced with microcontrollers. Just like the rest of the MQ sensors, the MQ-4 is most sensitive to a particular gas. This time, it’s methane, although the sensor can still detect other flammable gases like butane and propane.

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Using AD9833 Signal Generator with Arduino

Arduino AD9833 signal generator

How can you create sine, square or triangular waves with Arduino? Apparently, there’s a way with the help of an IC package -- the AD9833. With it, you can now create waveforms for communications, instrumentation, or other similar projects. My tutorial on building your own Arduino AD9833 signal generator after …

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Watchdog Timer on Arduino Tutorial

Arduino watchdog timer interrupt

In Arduino programming, we learn about functions setup() and loop(). Any code inside setup() executes once while code inside loop() executes again and again until the next reset. Now what if while inside the loop(), something went wrong either in code or in hardware? Normally we just press the reset …

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