4 Channel Relay Board


Quad Channel Relay Board is a simple and convenient way to interface 4 relays for switching application in your project.


  • Input supply 12 VDC @ 170 mA
  •  Output four SPDT relay
  •  Relay specification 5 A @ 230 VAC
  •  Trigger level 2 ~ 5 VDC
  •  Berg pins for connecting power and trigger voltage
  •  LED on each channel indicates relay status
  •  Power Battery Terminal (PBT) for easy relay output and aux power connection
  •  Four mounting holes of 3.2 mm each
  •  PCB dimensions 88 mm x 68 mm

4 Channel Relay Board – [Link]

Creating your first IoT Ethernet Device – IoT, Home Automation


In this series of tutorials show us how easy is to build a IoT Ethernet Device using ESP8266-01 WiFi module and how interface BMP085 barometric sensor, DS1307Z RTC, ILI9431 and log the data on a SD card.

As mentioned, this Instructable is split into two parts. Part (A) documents how relatively simple it is to cross port to Ethernet, extend and further develop an MQTT IoT device based around the ESP8266-01 WiFi enabled module from the earlier Instructable ‘Pimping your first IoT WiFi Device. Part 4 : IoT, Home Automation’

Creating your first IoT Ethernet Device – IoT, Home Automation – [Link]

Hacking the OWON SDS7102 Scope


Christer Weinigel did a teardown of OWON SDS7102 oscilloscope. He explained how its internals are connected, ported Linux to its Samsung SoC in the scope, succeeded in getting its peripherals working, and set to work programming the Xilinx FPGA that’s responsible for signal processing.

One of the reasons I bought this specific scope was that I had seen some teardowns of it and knew that the scope has a Samsung System-on-Chip (SoC) and a Spartan 6 FPGA in it and I have some familiarity with both. At the back of my head I had the idea that I might be able to reverse engineer the scope and do something interesting with it.

Hacking the OWON SDS7102 Scope – [Link]

AVR vs PIC: The case of the candle


A self-igniting candle implemented using AVR and PIC microcontrollers.

This project has two variations, one using an ATTiny25, the other using a PIC12LF1822.

In a series of minimalistic devices, this electronic candle periodically measures ambient light levels. Once it detects nightfall, it self-ignites and burns for three hours, flickering as a candle does. The flicker intensity changes about every minute, adding more variability.

AVR vs PIC: The case of the candle – [Link]


Arduino 8×8 LED Matrix using MAX7219


In this tutorial you will learn how to drive a 8×8 led matrix using MAX7219 display driver IC.

In this instructable I’m going to show you how to Interface with LED matrix using an Arduino and MAX7219 IC, this project can be used to make low resolution images using LEDs. This project is very simple to build and serves as a basics to getting started with controlling a large number of LEDs using the Arduino Uno.

Arduino 8×8 LED Matrix using MAX7219 – [Link]

Contactless OLED Thermometer With Arduino and MLX90614


Konstantin Dimitrov shows us how to build a contactless OLED thermometer using Arduino and MLX90614 infrared sensor.

Hello, everyone ! Today I’m going to show you how to make a contactless OLED thermometer with Arduino UNO and Infrared temp sensor MLX90614 in 5 minutes. This project is very simple, it requires basic programming and electronic skills to make it.

Contactless OLED Thermometer With Arduino and MLX90614 – [Link]

RuuviTag – Open-Source Bluetooth Sensor Beacon

Open-source sensor beacon platform designed especially for makers, developers and IoT companies. Some of the features are:

  • Easy to use
  • IoT and Bluetooth 5 ready
  • Filled with sensors (it can work as a weather station!)
  • Affordable
  • Attractive design
  • and last but not least — 100% Open-Source.

A year ago we started a design process with one goal: to create a superior open-source sensor beacon platform to fulfill the needs of developersmakers, hobbyists, students and even IoT companies and normal people. We managed to create one of the most advanced Bluetooth sensor products in the world.

RuuviTag – Open-Source Bluetooth Sensor Beacon – [Link]

Dark Sensitive Switch – LED Light


Dark activated LED light is a simple project which operates a LED when the light falling on the LDR goes below a set point.  The circuit is built using LM393 comparator, LDR as light sensor, preset (potentiometer) for sensitivity adjustment, transistor to drive the LED. The project can also be considered for use in energy saving application.


  • Input – 12 V @ 1A
  • LED 12V 500mA Maximum (6W)
  • Onboard Preset for Level Adjust
  • Operation LED Indicator
  • On Board Power LED
  • Header Connector for Power Supply and LED
  • PCB dimensions 55.45MM X 12.70 MM

Dark Sensitive Switch – LED Light – [Link]

Magnetic Field Measurement Using HMC5883 and Arduino Nano


In this tutorial we are going to learn the detailed working of HMC5883 with arduino nano.

The HMC5883is a digital compass designed for low-field magnetic sensing.This device has a wide magnetic field range of +/-8 Oe, and an output rate of 160 Hz. The HMC5883 sensor includes automatic degaussing strap drivers, offset cancellation, and a 12-bit ADC that enables 1° to 2° compass heading accuracy. All I²C Mini Modules are designed to operate at 5VDC.

Magnetic Field Measurement Using HMC5883 and Arduino Nano – [Link]