Boris Landoni from Open Electronics has designed and built another Christmas project the Spherebot, an open-source robot to draw on spherical objects: Let’s create a plotter to decorate Christmas Tree balls with writing and drawings. This machine: a printer, or better to say a plotter, which will draw with a marker on spheres at will, derived from models […]
Author Archives: DP
Arduino: OLED PCF8574 I2c back pack
Rupert Hirst writes, “After the success using the Midas MCOB21605G1V 1602 OLED display in my previous article. My next challenge would be connecting the module to my i2C backpack custom PCB, Using the PCF8574 i2c IC”
A DS1307 library for AVR Atmega
Davide Gironi has posted a DS1307 library for AVR Atmega: The DS1307 serial real-time clock (RTC) is a low-power, full binary-coded decimal (BCD) clock/calendar. This library set and get year, month, day, hour, minute and second from this RTC. Setup parameters are stored in file ds1307.h This library was developed on Eclipse, built with avr-gcc on […]
Laser pointer controlled with a PC mouse
Chirag Nagpal writes: I have created a laser pointer cotrolled through a PC mouse using an arduino and two servo motors. For getting the position of the mouse on the screen I’m running a small python script on the PC that uses the xlib library to get the current position of the mouse . This […]
A method of applying a precision reference voltage to an Arduino AREF pin, without accidentally blowing up the processor
Telford Dorr shared a tutorial on how to apply a precision voltage to the AtMega Aref pin without accidentally blowing up the processor. There’s a better way: feed the Aref pin resistor with an op-amp, and connect the op-amp negative feedback input directly to Aref. The op-amp will generate whatever output voltage is needed (within its […]
Saturn – Another attempt to make open source Spartan 6 FPGA board with DDR SDRAM
Tom of Numato Lab writes: We made a failed attempt to design and build a FPGA development board with DDR SDRAM last year. But this year we tried again and successfully built and tested a Spartan 6 FPGA board with DDR SDRAM. This board was built using KiCad and other open source tools. And best […]
A digitally controlled dual tracking power supply — III
Kerry writes: In part 1 of this series of blog postings, I showed my preliminary design of a dual tracking linear power supply. In part 2, I showed the completed design and also the finished power supply circuits. And as promised last time, I have made a couple of videos showing the measurements of a […]
#FreePCB via Twitter to 2 random RTs
Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]
Agilent 34461A miniseries part 1 Histogramm and Cdf
Michael Rubitschka writes: Today I received a Agiltent 34461A Truevolt multimeter from Xtest.at the Austrian Agilent distributor. I plan to write some articles about this multimeter and especially about features which imho separates it from it’s competition. I am a Hewlett Packard / Agilent fan but I will try hard to be as unbiased as […]
Making a mini LED Christmas tree
Raj just finished his mini LED Christmas tree project: My two and a half year old son loves toys with flashing lights. For this Christmas I thought of making a mini LED Christmas tree for him. This project uses 22 multi-color LEDs which are driven by a PIC12F683 microcontroller using the Charlieplexing technique. The details […]
USB and serial enabled LCD backpack back in stock
USB and serial enabled LCD backpack is back in stock at Seeed Studio. This board connects HD44780-compatible character LCD screens to your USB port. It works with apps like LCD Smartie to show news, system stats, and more on an external LCD. Get USB and serial enabled LCD backpack for $16.95.
Autopilot MEMs robot
Arduino compass bearing following robot: When you don’t want to drive your robot wouldn’t it be nice to just point in a direction and have it go there? Well the issue is that every little bump and wheel drag will slowly adjust the direction so where it ends up after 50 feet will most likely […]
Open Hardware Association releases first writeup about legal issues
Open Hardware Association releases first Writeup about legal issues: This blog post provides information from the legal discussions surrounding open source hardware in an open hardware legal meetup event hosted at NYU by Jason Schultz, founder of Defensive Patent License, November 11, 2013. OSHWA was very grateful to be part of the event. Legal professionals […]
555 as a push-pull level shifter
psmay writes: Wanting to prototype something with an oddball push-pull 3.3V-to-13V switch led me to concoct an experiment using only stuff available at a reasonably well-stocked Radio Shack[3], with particular attention to ICs that provide push-pull outputs. So far I’ve tried configurations based on the original 555 timer[4] and the TL082 op amp. My first […]
App note: Rework method for surface mount MLCCs
Things you might need to know about doing SMT rework on Multi Layered Ceramic Capacitors (MLCC). An application guide from TDK Rework is necessary when surface mount (SMT) components become misaligned or improperly mounted. This paper will answer questions concerning rework of SMT capacitors. Specifically, equipment, procedures, and technique are covered.
Free PCB Sunday: Pick your PCB
We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will […]
App note: properties and application of bypass capacitors
Another primer app note from NXP on capacitor bypassing. Bypass capacitors are applied between the power supply pins VCC and GND of integrated circuits. They reduce both the power supply noise and the effect of spikes on the supply line. They also provide instantaneous current demands of the integrated circuit as it switches. This application […]
App note: LCD biasing and contrast control method
Application note on direct Liquid crystal display driving using PIC microcontrollers. This Application Note provides methods that can be used to provide biasing voltages for Liquid Crystal displays. This document covers most of the biasing methods used in the PIC microcontrollers with an LCD controller.
App note: PICmicro device programming, what you always wanted to know (but didn’t know who to ask)
The basics of how to get your firmware into your PIC microcontroller. App note can be found here. For more than a decade, Microchip has published a lot of information about programming its 8-bit microcontrollers. There is now so much information out there, in fact, that it’s sometimes hard for engineers and technicians who are […]
Light up your XMAS from your Smartphone
Boris of Open Electronics writes: This post is about a light animation game that can light up your Christmas. There’s Bluetooth, Android and audio files: a perfect festive mashup. A spectrum analyzer will help us color the winter festivities. Every year at Christmas we always want to try something new for lighting up our decorations: […]