5 LDO regulator considerations other than voltage and current

James Lewis over at Bald Engineer writes, “For an AddOhms series, I created a DIY Arduino I am calling the “Pyramiduino.” It is an ATmega328p based board in the shape of a triangle. Other than being cute, the shape does not offer any other benefit. The design features a 3.3 volt LDO Regulator, which is […]

mavroOBD, an open source Arduino compatible OBD/Can-Bus module

Mavromatics’ open source project designed to “hack” your vehicle, that is available on github: The goal of this project it to create an Arduino based OBD port module that can be used to enhance a vehicles capabilites. For example, if you want door locks to close when moving faster than 5mph or to invoke/emulate certain […]

A DIY A4 laser engraver made from a scanner and a printer on ATmega328

In this video Davide Gironi demonstrates his DIY A4 laser engraver made from a scanner and a printer on ATmega328: This “Get Ready For Win98” Laser Engraving Machine it’s built using an old scanner, and an old printer. A laser engraving machine is a tool that uses lasers to engrave an object. Project info at Davide Gironi […]

DIY capacitance meter

Electro-Labs created new open source hardware project,  a DIY capacitance meter: This is a capacitance meter which can measure capacitors rated from picofarads to millifarads. The principle of operation is simple. Just apply voltage to the capacitor and measure the elapsed time to charge it. The circuit is based on Atmega328P and it is Arduino […]

DIY double sided 60W LED UV radiation unit with vacuum pump

Kurt Skauen has been working on a DIY 1188 LED dual sided UV radiation unit: The UV exposure unit is controlled by an ATmega328P microcontroller and have the following features: Single and double sided exposure. Each side radiated by a 594LEDs / 30W UV LED panel (The unit has a total of 1188 LEDs providing […]

A DIY laser engraver build using DVD and CD-ROM/writer

Here’s a DIY 38mm x 38mm laser engraver build using CD-ROM/writer on ATmega328p by Davide Gironi: A laser engraving machine, is a tool that uses lasers to engrave an object. To build this tool I’ve used two old CD-ROM writer that lays around in my garage. The X/Y positioning system it is build using the CD-ROM motor […]

Modify an off-the-shelf CP2102 module as an Arduino programmer

Kerry D. Wong wrote an article on how to modify a CP2102 module as an Arduino programmer: To make it work with the Arduino bootloader, one easy approach is to disconnect the RST header pin from CP2102 pin 9 and connect it to the DTR pin (pin 28) instead. While in the Arduino schematics, the […]

Simple 6x USB charger with current monitor

Frank Zhao shared his simple 6x USB charger with current monitor in the project log forum: This is a simple 6 port USB device charger with a individual current monitor on each port. The charging current is indicated using RGB LEDs. Blue means slow charge (under 250mA), green means 250mA to 750mA, red means over 750mA, and purple […]

Building a constant current/constant power electronic load

Kerry Wong built a DIY constant current/constant power electronic load.  It can sink more than 200W of power: A while back I built a simple constant current electronic load using an aluminum HDD cooler case as the heatsink. While it was sufficient for a few amps’ load under low voltages, it could not handle load much higher than a […]

An isolated DAC using PWM output

Kerry Wong writes: Arduino‘s (ATmega328P) PWM outputs via analogWrite can be conveniently turned into analog voltage levels through the use of simple RC filters. Since the PWM outputs are not isolated, using them to drive other devices directly could be potentially dangerous. This is especially true if the target circuit uses a higher supply voltage. […]

DIY digital wristwatch

Zak Kemble wrote a post on his blog detailing his digital wristwatch with a 1.3″ 128×64 OLED display, AVR ATmega328P microcontroller: The main incentive behind this project was to see how much I could cram, in terms of both hardware and software, into a wristwatch-like device that is no larger than the display itself. An OLED […]

Atmega328p PPM Encoder programming with the Bus Pirate

The Ardupilot guys have posted this brief tutorial on how to program the ATMega328p  using the Bus Pirate and AVRDUDE software: Connect the Bus Pirate and check that everything is working. You will need to use the same technique to locate the serial port name for the Bus Pirate that you use with Arduino. Note […]

Building a sweep generator for BK 4011

Kerry Wong documented his sweep generator build: In this post I will show you a simple sweep generator I built. It can be used to generate both the sweep waveform and synchronization signal needed for any function generator that has a VCG/VCO input. The sweep frequency can be adjusted from under a Hertz to several […]

DIY ethernet temperature and humidity logger

Kerry Wong built an Ethernet temperature and humidity logger: I used an ENC28J60 Ethernet module along with an ATmega328p microcontroller to log the temperature and humidity readings and then process the data on my web server for display. To plot the data points, I used Google Annotated Timeline so that you can easily zoom into the […]