How to Access the Raspberry Pi GUI with a Remote Desktop Connection has a tutorial on how to access Raspberry Pi with a remote desktop connection.

In the previous post, we learned how to set up a WiFi dongle and access the Raspbian command prompt via an SSH client called PuTTY. PuTTY is a great application for accessing the command line in Raspbian from another computer, but you can’t use it to access the Raspbian desktop (GUI). In order to access the Raspbian GUI from another computer, we need to configure it to work with a remote desktop application. This will allow us to access our Raspberry Pi desktop (or the command line) from anywhere in the world as long as we have a computer with an internet connection.

How to Access the Raspberry Pi GUI with a Remote Desktop Connection – [Link]

Tic Tac Toe Game with a touch screen and an Arduino Uno

In this Arduino project video is going to build an Arduino Game, a Tic Tac Toe game with a touchscreen.

In this video we are going to build an Arduino Tic Tac Toe game. As you can see, we are using a touch screen and we are playing against the computer. A simple game like Tic Tac Toe is is a great introduction to game programming and Artificial Intelligence. Even though we won’t be using any Artificial Intelligence Algorithms in this game, we will understand why Artificial Intelligence Algorithms are required in more complex games.

Tic Tac Toe Game with a touch screen and an Arduino Uno [Link]

Building A Tiny Portable Time-lapse Camera

Using a mini spy camera module, Ruiz Brothers had built a tiny portable camera that is used to take time-lapse videos and for all sorts of photo based projects.

This project consists of these parts with an estimated cost of $39:

The mini spy camera module has an integrated driver and is easy to use without an Arduino or Raspberry Pi. The camera sensor can take 1280×960 photos and captures video at 480p. The module uses a microSD card to store data and it has a maximum support of 32GB. For a higher image quality and adjustable settings, you can use other camera modules such as the Wearable Raspberry Pi Zero Camera.

To take a time-lapse, an intervalometer remote control is needed to trigger the camera for capturing a photo within a constant interval. The Adafruit Trinket microcontroller is used here, and you can also make your own following this guide.

The circuit will be powered by a 3.7V 100mAh Lithium Ion battery via JST connection. The battery plugs directly into the Trinket Backpack, which allows the recharging over the microUSB port on the Trinket.

The circuit is connected as shown in the diagram; the slide switch to Lipoly backpack, VCC from camera to 5V on Trinket, GND from camera to GND on Trinket, BAT from Lipo backpack to BAT on Trinket, G from Lipo backpack to GND on Trinket, and 5V from Lipo backpack to USB.

The code is very simple and can be uploaded to the controller using the Arduino IDE. The setup loop will initialize the pins, and the loop will turn on and off the trigger with a chosen delay.

int trig = 0;
int led = 1;
void setup() {                
  // initialize the digital pins as output.
  pinMode(led, OUTPUT);
  pinMode(trig, OUTPUT);         
  digitalWrite(led, HIGH);  
  digitalWrite(trig, HIGH); 
// Hold HIGH and trigger quick (<250ms) LOW to take a photo. Holding LOW and trigger HIGH starts/stops video recording
void loop() {
  digitalWrite(trig, LOW);   
  digitalWrite(led, HIGH);
  digitalWrite(trig, HIGH);    
  digitalWrite(led, LOW);   

The case in 3d printed, the design with a detailed description and the full making guide is available here. This video is showing how to make this tiny camera and how it works.

Reverse-engineering the ALU of 8008 microprocessor

Ken Shirriff has written an article on reverse engineering the ALU of the 8008 microprocessor:

A computer’s arithmetic-logic unit (ALU) is the heart of the processor, performing arithmetic and logic operations on data. If you’ve studied digital logic, you’ve probably learned how to combine simple binary adder circuits to build an ALU. However, the 8008’s ALU uses clever logic circuits that can perform multiple operations efficiently. And unlike most 1970’s microprocessors, the 8008 uses a complex carry-lookahead circuit to increase its performance.
The 8008 was Intel’s first 8-bit microprocessor, introduced 45 years ago.1 While primitive by today’s standards, the 8008 is historically important because it essentially started the microprocessor revolution and is the ancestor of the x86 processor family that are probably using right now.2 I recently took some die photos of the 8008, which I described earlier. In this article, I reverse-engineer the 8008’s ALU circuits from these die photos and explain how the ALU functions.

Reverse-engineering the ALU of 8008 microprocessor – [Link]

Low-Cost FPGA With Reconfigurable Electronics Feature

Iolinker is a cheap 64 FPGA board with a MachXO FPGA that functions as a dynamically configurable IO matrix. Its main functionality, besides IO extension, is to dynamically set up a matrix of GPIO connections, that allow direct pass-through of high-frequency signals. Circuits can thereby be configured and programmed on the fly. There are UART / SPI / I2C connections that allow for easy integration of up to 127 chips connected in parallel.

Thanks to the open source library, Iolinker allows developers to create reconfigurable, easy to self test electronics within minutes. It can be used to be an IO extender and can output PWM signals. In addition, its revolutionary “IO linking” feature allows to dynamically pass through high-speed signals between IOs, better than any microprocessor ever could.

Check this teaser about the new board:

Iolinker has the following specifications:

  • Reprogrammable FPGA board with Lattice LCMXO3L-4300E-5UWG81CTR50
  • Preprogrammed and usable out of the box as your IO interface of choice.
  • 49 GPIOs for PWM or IO extension usage, VCCIO is 3.3V.
  • Boards can be connected in parallel, to create endless IO extension.
  • IOs can be linked to each other, i.e. you tell the FPGA to connect them, and it forwards the input signal from one pin to another. (Read more about the iolinker chip function.)
  • UART, SPI or I2C interfaces are available.

In order to make the ultimate IO interface for users, the team are accepting feature requests at the contact page.

In short, the Iolinker board is easy to use and can reconfigure schematics on the fly, what makes it ideal to reduce prototyping time and jumper cable mess, and to maximize the ability of using IO extensions.

More technical details about Iolinker and its price will be announced soon at the Kickstarter campaign at Feb 14. Some special offers are for everyone who register in the website’s newsletter, so register now and stay tuned!


Introduction to Digispark has a quick review of the Digispark board. It’s a really interesting mini board that can be used in small projects using Arduino IDE.

In today’s blog post we’ll analyze one of the smallest and most practical boards out there. The Digispark board. It’s size, including the USB port, is 25mm x 18mm (so tiny)!! This little board is powered by an ATTINY85 chip and clocked to 16.5Mhz. For conveniece, it has a built in USB port and can be plugged into a your computer without cables or adapters. Now that’s pretty awesome! It is powered by either the USB port, from the +5v pin with regulated 5v or from VIN pin if unregulated. The VIN pin supports from 7v to 35v although less than 12v is recommended by the manufecturer.

Introduction to Digispark – [Link]

NTP synchronized clock

The Network Time Protocol (NTP) is the most commonly used internet time protocol for synchronizing locally running clocks to a more accurate reference clock server. In United States, the official time is provided by the National Institute of Standards and Technology (NIST). The NIST servers listen to a NTP request, and respond by sending a 64-bit UDP/IP data packet containing the time in UTC seconds since January 1, 1900, with a very high time resolution of 200 picoseconds. Raj from Embedded Lab illustrates in his new tutorial how to make an ESP8266 based internet clock that is synchronized with the NIST time server for accurate timekeeping. An ILI9341-driven colorful TFT LCD is used to display time in both analog clock dial and digital formats. Raj used EasyESP-1 board for this tutorial and developed the firmware for his internet clock using Arduino IDE.

ESP8266-based internet clock

Export Eagle Libraries With SnapEDA

Although the new Eagle subscription model by Autodesk will bring much-needed features to the software, many users after the announcement had decided to move their work to other alternatives, such as KiCad, Altium, Cadence, etc.

One of the challenges was to convert the libraries made by Eagle to be compatible with other software programs. SnapEDA solved that by offering a new free tool that translates Eagle libraries to KiCad, Altium, OrCad and other formats.

SnapEDA is a parts library for circuit board design provides free symbols, footprints, and 3D models for millions of electronic components. The goal behind SnapEDA is to build one trusted, canonical source of electronics design content that everyone can benefit from.

To convert your Eagle library just upload your file here, then you can re-download it in any format through your uploaded models page. The video below demonstrates the converting process:

Currently, all the uploaded parts will be public on SnapEDA until the private version is released. All parts are clearly marked as user-generated content and attributed to the uploader, and can be deleted at any time.

“We are big fans of Eagle and the new changes they’re making, and are confident that the subscription model will bring much-needed features to the software. But we also understand that it is (for many) a showstopper. Hopefully this free tool is helpful to those for whom this is the case.” – SnapEDA

Try now this tool and convert your files here!

Increasing Battery Life With UB20M Voltage Detector

Engineers at the University of Bristol have developed a three terminal pico-power chip that can cut standby drain in sensor nodes – even compared with today’s low-power microcontrollers.

It does this by replacing the low duty-cycle sleep-wake-sleep pattern used on MCU-based sensor monitors, with ‘off’. A voltage detector powered by the sensor – there is no other power source –  starts the processor when the sensor produces a voltage.

At 5pA (20°C 1V), power draw from the sensor through the input/supply pin is so low that the chip can directly interface with high-impedance sensors such as antennas, piezo-electric accelerometers, or photodiodes. With so little current required, the chip does not collapse the sensor voltage.

“It will work from five infra-red diodes in series, powered from a TV remote control 5m away, or an un-powered accelerometer”, Bristol engineer Bernard Stark told Electronics Weekly.

Called UB20M, the only power it draws from the system is 100pA(max) leakage through its open drain output transistor. Input threshold is set at 0.6V.

Once the sensor presents greater than 0.6V to the input, the output FET turns on (RDSon~800Ω), and its low resistance can either be used to turn on a p-FET to power up a microcontroller, or can wake a microcontroller from sleep.

In an extreme application example, said the University, an earthquake detector could be held in sleep for years, until a tremor caused the chip to wake its host.

Despite its impedance and sensitivity, the device can withstand 20V on its input/supply pin, and it has ESD protection. Maximum output pin parameters are 5.5V 7mA. Output turn-on time is 0.25μs, while turn-off depends on load resistance and capacitance – typically 8μs with a 5MΩ load and 180μs with 100MΩ.

Because patents are pending, exactly how the chip works is not being disclosed. It has around 40 transistors, and is made on a 180nm CMOS process, is all Stark could say.

Samples are available – through a multi-project wafer deal with Europractice and IMEC, fabricated at AMS in Austria, and the University has created an evaluation board. Due to Europractice and IMEC going the extra mile, said Stark, samples are in SOT323-5 rather than clunky research packages.

The team cautions that anyone trying the chip will need to understand high-impedance circuits, as otherwise stray mains fields, for example, will trigger it continuously and the output transistor will remain on. Lengthy sensor connections should be avoided.

In general, the sensor has to be connected to the input/supply pin with enough parallel resistance to leak away stray charge and ensure the UB20M turns off.

“We are now working on ways of bringing other power drains such as data-capture, computation, and transmission, to within the nW-power budget of a sensor, completely eliminating batteries from sensor nodes,” said the University. “An example of this (right) is where power management with a few tens of nW quiescent is actively matching its input impedance to an 80MΩ energy harvester with 10 ms intermittent output pulses.”

UB20M data sheet and eval board details can be reached from this introductory web page, and there is an introductory video.

Source: Electronics Weekly

12V @ 120mA Transformerless Power Supply

The circuit provided here is a transformer-less non-isolated power supply which is capable of delivering an output of 12V at 120mA current for an input voltage varying from 85VAC-265VAC. The LNK304 is the heart of this circuit which supports buck boost and flyback topologies. This project is low in cost and simple when compared other tramsformer-less power supplies.


  • Input(V): 85V AC to 265V AC
  • Output(V): 12V DC
  • Output load: 120mA
  • PCB:75mm X 35mm

12V @ 120mA Transformerless Power Supply – [Link]