TFoC: FPGA & Forth = VGA


Here is a fun project, created from start to finish by Matthias Koch:

In itself, this is no big deal. The generated pattern is a 16×16 expanded pixel image, and 640×480 displays are pretty basic by now – although they’re fine for presenting text-mode information and retro games.

TFoC: FPGA & Forth = VGA – [Link]

Opto-isolated laser controller build


Scott Harden built his own opto-isolated laser controller and wrote a post on his blog detailing its assembly:

My goal was to utilize a free hardware output line to signal to a device that I build to modulate the laser in a special way. This way there would be no modification to any existing equipment, and no software to install. Further, since this hardware isn’t mine, I don’t like the idea of permanently modifying it (or even risking breaking it by designing something which could damage it by connecting to it). The specific goal is to allow the existing software to cause the laser to fire 20 ms pulses at 15 Hz for a few dozen cycles of 5s on, 5s off. It’s also important to have some flexibility to reprogram this firing protocol in the future if a change is desired.

Opto-isolated laser controller build – [Link]

App note: Solid-State Relays


Solid-state relays introduction from Vishay, (PDF)

MOSFET SSRs feature an optocoupler construction, but have a pair of MOSFETs on the output instead of a phototransistor. A pair of source-coupled MOSFETs emulate an electromechanical relay by providing bidirectional switch capability and a linear contact. No output power supply is required.

App note: Solid-State Relays – [Link]

MAX232: The classic IC lives on since 1988


by Len Sherman @

The June 23, 1988 issue of EDN included a Maxim Design News insert where we asked “Who in their right mind would choose a computer interface standard that uses ±12V supplies, requires expensive connectors, works over a limited distance, is error prone, difficult to network, and has no current loop isolation?” Yet, here we are 28 years later and the classic interface lives on, particularly in industrial applications and applications that need to connect just one peripheral to a host computer.

MAX232: The classic IC lives on since 1988 – [Link]

FARMBOT Open-source CNC Farming Machine


FarmBot is an open-source CNC farming machine designed for small-scale precision food production. Similar to any CNC milling machine, FarmBot hardware employs linear guides in the X, Y and Z directions for tooling. FarmBot tools include: seeder, watering nozzle, camera, weeder and soil sensor.


FarmBot is powered by a Raspberry Pi 3, Arduino Mega 2560 and RAMPS 1.4 shield. All of FarmBot’s plastic components are designed to be 3D printed. FarmBot team have made a very detailed step-by-step assembly instructions, bill of materials and technical specifications for every part.

FarmBot is controlled and configured using the FarmBot web application, which looks like a game!.




Mumai – Control Anything Using your Muscles

Alvaro Villoslada designed an open-source muscle-machine to control any kind of electronic device through the myoelectric (EMG) signals. The name of this project is Mumai and it is published on


“The Professional EMG systems are very expensive, cumbersome and complex” Alvaro said. And that is the problem which Alvaro tries to solve in this project. He aims to develop an affordable and open-source wearable wireless network of EMG sensors, that can be placed on any muscle to control devices, ranging from computers or smartphones to robots, using EMG signals.


Alvaro wants to equip each EMG sensor with an ESP8266 module to get the digitized signals and to send them wirelessly, forming what he called a Mumai node.

You can get all source files from github repository, including the PCB and schematic files. Alvaro uploaded an Arduino sketch file of an application for his project, which is a bruxism detector.

Finally, for more in depth information, “The EMG sensor used in this project is based on my MSc thesis, where more information regarding the design and operation of the circuit can be found” Alvaro said.

[Project Page]

Simple two-transistor circuit lights LEDs


Barry Tigner @ has a design idea on how to power a LED from a 1.5V battery using two easily available transistors.

A previous Design Idea describes a circuit that uses an astable multivibrator to drive an LED (Reference 1). The circuit in Figure 1 uses a simpler alternative approach. The circuit uses a 2N3904 NPN transistor and a 2N3906 PNP transistor, which operate as a high-gain amplifier.

Simple two-transistor circuit lights LEDs – [Link]

Google’s quantum computer just accurately simulated a molecule for the first time


Google’s engineers just achieved a milestone in quantum computing: they’ve produced the first completely scalable quantum simulation of a hydrogen molecule. by DAVID NIELD @

Researchers working with the Google team were able to accurately simulate the energy of hydrogen H2 molecules, and if we can repeat the trick for other molecules, we could see the benefits in everything from solar cells to medicines.

These types of predictions are often impossible for ‘classical’ computers or take an extremely long time – working out the energy of something like a propane (C3H8) molecule would take a supercomputer in the region of 10 days.

Google’s quantum computer just accurately simulated a molecule for the first time – [Link]

Measure Weights Using OpenScale from Sparkfun

Sparkfun has a simple-to-use and open source solution for measuring weight and temperature. All you need is a load cell hooked up with OpenScale.


OpenScale uses HX711, a 24-bit analog-to-digital converter (ADC) specifically designed for weighing scales. It’s connected with an Atmega328P through a serial data line to get the reads from HX711. Atmega328P is running Arduino and an extensive pre-loaded configuration firmware to create an off-the-shelf solution for load cell reading.


You can get the output using the on board FT231 through USB terminal or directly get UART signals through the serial out connector. Also, Openscale uses TMP102, as on board temperature sensor. You can also connect an external one.


To get more details, you can refer to the detailed OpenScale guide.

[Product Page]

Arduino Proximity Alarm


Lucas Reed @ has build a proximity alarm using Arduino and an ultrasonic sensor from Parallax. If a nearby object is approaching then the alarm will sound and an RGB LED will light up. He writes:

An ultrasonic rangefinder and Arduino microcontroller will check for nearby objects and if need be, alert you with a piezo-buzzer and RGB LED. Learn about these components using electronics lab simulations and eventually design, code, simulate, and build the proximity alarm itself! This is great if you are looking for a quick project to learn about digital electronics.

Arduino Proximity Alarm – [Link]