Make a supercapacitor with a DVD writer

Professor Kaner from UCLA demonstrates how to build a high-performance graphene-based supercapacitor with a DVD writer [PDF!]. The process uses a DVD writer to burn a pattern onto a plastic film coated with graphene. The resulting supercapacitor is flexible, and capable of storing enough energy to drive an LED for a few minutes. There has been […]

Build a low speed scope with a PIC18F2550 and a graphical LCD

Steve build a low speed scope from a PIC18F2550 microcontroller and a graphical LCD. The MCU takes 60k samples per second from it’s analog-to-digital converter. It proceeds to process the signal and display it and some basic information on the screen. Steve left the source code, and the schematic on his site. Using the PIC18F2550 […]

8 Channel USB digital signal generator

  Dilshan developed a 8 channel USB digital signal generator and an open source Windows application called Kidgo Player to drive it. The hardware is basically just a PIC18F2550 USB breakout board used to provide 8 digital outputs for his software. The Kidgo Player’s source is available on GitHub, and has the following features: Save […]

3D printed wire stripper with a wire contact indicator

Bjbsquared designed a wire stripper tool with a LED indicator that flashes when contact with the wires is made. To built it you’ll need to get the model laser cut from acrylic or 3D printed. This is one of the best wire strippers I have ever used. If setup correctly, it can be very precise […]

DIY Magnetic rotary encoder with AS5043

Sebastian would like to build a high-res 3D printer, and to this end he needs a precise way to ascertain the exact positions of various moving parts. Instead of buying an expensive stepper motors he decided to build a magnetic rotary sensor with which he could calculate the distance traveled. By placing a neodymium magnet […]

Reverse engineering car parking sensors

James decided to reverse engineer car ultrasonic parking sensors. These sensors have integrated electronics that handle all the measurements. They are connected to the car’s internal computer via a low-speed single wire CAN network. James provides pinouts, protocol interface, and some source code to interface with them. Since I know a thing, or two, about […]

Testing the photovoltaic effect with a transistor

When you expose the silicon die of a transistor to a light source a charge is produced. CircuitsDIY opened up a 2n3055 transistor and did some experimenting. With the help of a magnifying glass he was able to built up a charge of 0.65V and produce 42.2mA of current. Most photovoltaic cells are made of […]

Builld a touch activated Valentine’s LED card

Happy Valentine’s from Dangerous Prototypes. This touch activated Valentine’s card is one of Ian’s early projects at DIY Life. It’s designed to be home-etched on a single-sided PCB. A PIC16F microcontroller fades the LEDs like a heart beat. It’s activated when someone touches the conductive pad, which allows current through a PNP transistor and wakes […]

DIY rosin solder flux made with isopropyl alcohol

Arhi tried his hand making DIY rosin-based solder flux. He added crushed rosin to isopropyl alcohol until it had the desired viscosity. The video is a test of the new flux on 1 mm and 0.5 mm pitch components. By his account it works better then some commercial products, but there’s also more smoke and […]

Serial port monitor with 2×20 LCD and 4K text buffer

Kerry uses a DIY serial display to show debugging data sent from an Arduino’s UART. Sometimes the data comes too fast to read, so he added a 4K buffer and controls to scroll thorough the history. …if your application generates a lot of messages, it would still be hard to spot the relevant information as […]

DIY MMA7455L 3-axis accelerometer breakout

Here is a DIY breakout board for the MMA7455L, an inexpensive three-axis accelerometer. It’s got all the decoupling capacitors and pull-up resistors specified by the accelerometer datasheet.There’s also an interfacing tutorial for the Arduino. We like this chip because it’s cheap, but the LGA package is difficult to solder. If you’re not up for soldering […]

DIY Chronodot, homemade RTC with a battery backup

Valentin built a DIY version of the Chronodot real-time clock with battery backup. He used some disc shaped perfboard to assemble all the components. There is an optional component that you can add – a real time clock (RTC) with battery back up. It is called Chronodot RTC. All it does is ensure that clock […]

DIY geomagnetic storm monitoring

With the recent increase in solar storm activity, Alexander Avtanski bring our attention to his DIY magnetometer project. The activity of the Sun varies on a cycle with a period of approximately 11 years. Periods of low solar activity are followed by a few years of sharply increased number of solar spots, flares, and coronal […]

Roundup of tips and tricks for breadboards

Breadboards are a really helpful tool for quick prototyping. Boseji made a roundup of breadboard tips and tricks available online. His article includes useful tips like how to breadboard a power supply, and even how to build one yourself. We have all used breadboards, or those who plan to jump into the fascinating world of […]

High-voltage arcs using a flyback transformer from a monitor

Hak8or uploaded a gallery of high voltage arc pictures. The setup was salvaged from an old CRT monitor. He suspects the flyback transformer produces around 30 kV. I found some old pictures of me playing around with a flyback, and I wanted to test out this awesome gallery thing I found, so I mushed them […]

Digital light intensity meter with a calibrated LDR

Shawon made a light intensity meter using an ATmega microcontroller to read a light-dependent-resistor and display the values on a 2X16 character display. To calibrate his LDR he used a digital light meter and a dimmable light source. This allowed him to plot the sensor output and properly calibrate his device. This project is about […]