Simple RFID based Door Lock using Arduino


by JOJO @

Its quiet fun to work with RFID based projects! In the previous article, we saw how to interface RFID with Arduino. Interfacing is the first step to create any useful project. So why don’t we create an RFID based Access Control System or an RFID based Door Lock using Arduino? The system I have designed here is a simple version of the project. This project can be enhanced with a lot of features (which I will be doing in the next version of this project – Advanced RFID based Door Lock). So lets begin!

Simple RFID based Door Lock using Arduino – [Link]

ESP8266 WiFi touch screen thermostat


by EasyIoT @

In this tutorial we will show how to build WiFi controlled thermostat with ESP8266, Arduino and touch screen display. Thermostat will also show other info, like weather forecast and temperature outside. Total cost for thermostat is about 40EUR, which is price for basic commercial thermostat in shop.

Basic features:

6 modes – Auto, Off, LOLO, LO, HI, HIHI
Touch screen
WiFi connected
Four set temperatures (LOLO, LO, HI, HIHI) and weekly schedule
Time display
Additional data display – temperature in other room, air pressure and weather forecast

ESP8266 WiFi touch screen thermostat – [Link]



Dual op amp affords 30-µV precision


by Susan Nordyk @

Supplied in an 8-lead MSOP, the LT6023 dual micropower op amp from Linear Technology provides an input offset voltage of 30 µV maximum and settles to 0.01% in 60 µs, making it useful for multiplexed data-acquisition systems and precision signal processing. Proprietary slew-enhancement circuitry results in a fast, clean output step response with low power consumption.

Specially designed input circuitry maintains high impedance, which minimizes current spikes associated with fast steps for input steps up to 5 V. Slew rate is 1 V/µs, while maximum supply current is 20 µA/amplifier. The LT6023 also includes a shutdown mode that reduces supply current to less than 3 µA when the part is not active. An enable time of 480 µs and a fast slew rate combine to provide power-efficient operation in duty-cycled applications.

Dual op amp affords 30-µV precision – [Link]

Arduino IDE released for ESP8266


Richard over at ESP8266 CommunityForum writes,

I have setup a new section for ESP8266 Arduino as IGRR and myself have successfully ported the Arduino IDE over to the ESP8266 and have it all working very nicely now. ESP8266 Arduino and the code is on github, we have also set up a compilation server and executables will also be available for download. So go to town and start writing Arduino code the ESP8266! Get your ideas off the ground in no time! FAST!

Arduino IDE released for ESP8266 – [Link]

Raspberry Pi Solar Weather Station


by PiJuice @

Spurred on by the completion of my two previous projects, the Compact Camera and Portable Games Console, I wanted to find a new challenge. The natural progression was an outdoor remote system…

I wanted to build a Raspberry Pi weather station that was able to sustain itself off grid and send me the results through a wireless connection, from anywhere! This project really has had its challenges, but luckily powering the Raspberry Pi is one of the main challenges that has been made easy by using the PiJuice as a power supply with it’s added solar support.

Raspberry Pi Solar Weather Station – [Link]

Find transistor replacements and information


You can find technical information about transistors and replacements with just a few clicks at

Find transistor replacements and information – [Link]

Variolab+ laboratory furniture can help also to you


Highly variable tables and furniture Variolab+ are suitable for education and also for production/ service. Thanks to a wide range of various modules it´s possible to arrange a configuration that perfectly suits your needs.

It´s possible to work in various conditions. Excessively said – even on a classic office table. However, for a really effective work it´s certainly better to use a table, where everything is there, where you want, it has a correct height, offers a lot of space for the work itself, it´s safe and it also might be ESD safe…

Variolab+ laboratory tables produced by a Czech company Diametral meet the highest criteria of ergonomics and safety. A few-thousand (Euro) investment for a common configuration of such table is probably too much for a beginning designer, but for fully engaged production-, service- and testing workplaces as well as school classrooms this equipment quickly “refunds”. For example thanks to these reasons:

  • maximal workspace while maintaining all devices easy to reach (power supplies, circuit breakers, measuring equipment, isolating transformer,…)
  • minimum time to start a work, high efficiency of work/ education
  • possibility of a central remote control (for example by a teacher) or also to adjust max. voltage limit and similar
  • high safety, certified solution
  • enables to compose a table exactly according to your needs with maximal usage of available space
  • stable construction from robust steel components treated by a powder baked coating (long-term stable construction, stronger than similar one from aluminium)
  • modular design enables to choose from a large amount of electric and electro-mechanical modules, which can be installed in a rear part of a work-desk as well as above the work-desk
  • open system enabling anytime to add other modules, superstructure,..
  • up to 150 kg work-desk load capacity thanks to a robust frame beneath the desk
  • superstructure with devices (modules) can be placed on a work-desk or above the work-desk (to reach a max. space)
  • possibility to equip also with pneumatic elements (air distribution,…)

Wide range has a standard height of 200mm and width in multiplies of 60mm. Basic work-desk can be equipped with boxes, cabinets, shelves, drawers, tiltable oscilloscope holder, tools holder,…. Among modules, which can be integrated in a table also belong a soldering station, oscilloscope, RLC decades, as well as various AC and DC power supplies, regulation transformers, circuit breakers,… Moreover, tables can be stacked into various sets and we´re also able to supply you with laboratory cabinets, chairs,….

For illustration we also bring you some photos of typical worktables, which we supplied to our customers. Guide price of such a table is approximately 4000 to 4500 Eur. Resulting price is naturally strongly dependent on types and amount of modules used in a given table.

Variolab+ laboratory  furniture can help also to you – [Link]

New process could make gallium arsenide cheaper for computer chips, solar cells


by Tom Abate @

Computer chips, solar cells and other electronic devices have traditionally been based on silicon, the most famous of the semiconductors, that special class of materials whose unique electronic properties can be manipulated to turn electricity on and off the way faucets control the flow of water.

There are other semiconductors. Gallium arsenide is one such material and it has certain technical advantages over silicon – electrons race through its crystalline structure faster than they can move through silicon.

But silicon has a crushing commercial advantage. It is roughly a thousand times cheaper to make. As a result, gallium arsenide-based devices are only used in niche applications where their special capabilities justify their higher cost.

Cellphones, for instance, typically rely on speedy gallium arsenide chips to process the high-frequency radio signals that arrive faster than silicon can handle.

New process could make gallium arsenide cheaper for computer chips, solar cells – [Link]

The Qduino Mini



Quin Etnyre has been into all things Arduino since he was a kid. He already has 28 Instructables published, founded his own company called Qtechknow in 2012 which sells ArduSensors and a line of fun and educational kits and oh, he is still just 14 years old.

His latest Arduino-based design is the Qduino Mini which is the first tiny Arduino compatible board to incorporate a battery charger and fuel gauge to let you know when the battery needs recharging.

The Qduino Mini is 1 inch by 1.5 inches and weighs just 5 grams which makes it ideal for use on airborne projects such as quadcopters, drones or high altitude balloons.

Main features of the Qduino Mini:

ATmega32U4 Processor – Arduino Leonardo compatible
32 KB Flash storage
3.3 V @ 8 MHz
20 digital I/O // 14 dedicated
12 analog Channels // 6 dedicated
7 digital I/O also PWM channels
SPI, I2C, UART available
LED Indicators for: ON, charge status, TX, RX, D13
TPS78233 3.3 V 150 mA regulator
MCP73832 LiPo battery charger
MAX17048 LiPo battery fuel gauge

The Qduino Mini – [Link]

32-bit Microcontroller Chip – Next-Generation, Eco-Inspired


Eco-Inspired 32-bit microcontroller chip for Wearables and the Internet-of-Things.

DREAM-1 is a Next-Generation, Eco-Inspired 32-bit microcontroller chip for Wearables and the Internet-of-Things;
No limitations – powered by Eco-Logic technology: minimal energy, maximum speed, event-driven, instantaneously responsive and energy-performance adaptive;
Fully compatible – DREAM-1 apps can be developed with existing software flows, programming languages and configured wirelessly over Bluetooth;
Exclusive – limited sampling batch only available on Kickstarter to perfect its design.

32-bit Microcontroller Chip – Next-Generation, Eco-Inspired – [Link]