16DecDecember 16, 2025

ESP32 with Dot Matrix Display (MAX7219)

📌 What is the Dot Matrix Display with MAX7219?A Dot Matrix Display is an arrangement of LEDs in a grid (commonly 8x8) used to display text, symbols, numbers, or animations. When combined with the MAX7219 driver chip, it becomes much easier to control multiple displays using just 3 wires (SPI) from the ESP32.🧠 Key Features of Dot Matrix with MAX7219FeatureDetailsDisplay TypeLED Dot Matrix (8x8 per module)Module DriverMAX7219InterfaceSPI-compatible (DIN, CLK, CS)Voltage5V (logic safe for ESP32)CascadableYes (multiple modules side-by-side)Control LibraryMD_Parola / MD_MAX72xxBrightness ControlYes (adjustable via software)⚙️ Pinout of...

IoT0 CommentsLike: 0

16DecDecember 16, 2025

Motion Detected: ESP32 with PIR Sensor (HC-SR501)

🧠 What is a PIR Sensor?PIR = Passive Infrared SensorA PIR sensor detects motion by measuring changes in infrared radiation.Every warm object (like humans and animals) emits infrared (IR) radiation.PIR sensors don’t emit anything; they only detect IR changes. That’s why they are called passive.🧪 How Does It Work?The PIR sensor has two slots made of pyroelectric sensors.When a human or animal moves in front of the sensor, one slot sees more IR radiation than the other.This sudden change causes a voltage difference and the sensor outputs HIGH (3.3V or 5V) for a short...

IoT0 CommentsLike: 0

16DecDecember 16, 2025

ESP32 with SIM900A GSM Module

📡 What is SIM900?The SIM900 is a GSM/GPRS module from SIMCom. It allows microcontrollers like ESP32 or Arduino to:✅ Send/receive SMS✅ Make/receive phone calls✅ Connect to the Internet (GPRS)✅ Send data to servers via HTTP, MQTT, TCP/IPIt communicates via UART (TX/RX) and uses AT commands.📦 Features of SIM900FeatureDescriptionNetwork2G GSM (850/900/1800/1900 MHz)CommunicationUART (AT commands)Baud RateDefault 9600SIM CardStandard-size SIM (2G supported)Power Supply5V–12V, 2A recommendedAntennaRequired for GSM signalOptionalMic & Speaker (for calls)🔌 SIM900 to ESP32 ConnectionSIM900 PinESP32 PinTXGPIO 16 (ESP32 RX)RXGPIO 17 (ESP32 TX)GNDGNDVCC⚠️ External 5V 2A power supply⚠️ DO NOT power SIM900 directly from ESP32 or USB....

IoT0 CommentsLike: 0

15DecDecember 15, 2025

Rotary Encoder with Esp32

23-07-2025📌 What is a Rotary Encoder?A rotary encoder is an electro-mechanical sensor that converts the angular position or motion of a rotating shaft into digital signals. Unlike a potentiometer, it can rotate infinitely in either direction and is commonly used in digital volume knobs, step selection, or menu navigation.In this blog post, we will explore the functionality, applications, and code implementations of rotary encoders with the ESP32 microcontroller.They are crucial for applications requiring precise control and feedback, making them essential components in various electronic devices and systems.There...

IoTarduino, Embedded Systems, esp32, ESP32 Projects, GPIO Input, Interrupts, IoT, Quadrature Encoder, Rotary Encoder, Sensor Interface0 CommentsLike: 0

15DecDecember 15, 2025

DFPlayer Mini with Esp32

🎵 What is DFPlayer Mini?The DFPlayer Mini is a tiny, standalone MP3 audio player module. It can play audio files (MP3/WAV) stored on a microSD card. You can control it through:Serial communication (UART with ESP32 or Arduino)Built-in IO pins (for button-triggered audio)Library-based commands to control volume, play/pause, next, loop, etc.📦 DFPlayer Mini PinoutPinFunctionVCCPower (3.2V–5V)GNDGroundTXSerial Transmit (connect to ESP32 RX)RXSerial Receive (connect to ESP32 TX)SPK1, SPK2Speaker output (mono, 3W)DAC_L/RStereo line out (for headphones/amp)IO1/IO2Button controlBUSYLOW when playing🔌 Wiring DFPlayer Mini with ESP32🔧 ESP32 to DFPlayer Mini (Serial Connection):DFPlayer PinESP32...

IoT0 CommentsLike: 0