Free PCB coupon via Facebook to 2 random commenters

in Free PCBs by DP | 0 comments


Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters.  The coupon code usually go to Facebook ‘Other’ Messages Folder .  More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week:

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Use ESP8266 module as a wireless switcher

in how-to, wireless by DP | 0 comments


Razvan Dubau over at Extragsm posted a how-to on using an ESP8266 module as a wireless switcher:

A custom firmware to transform the ESP8266 wifi module into a wifi http based switcher
GPIO02 is used as an output pin. You can connect a led or a relay and controll it by a button added to GPIO00. Also the firmware provides a web interface and a simple API that will controll the GPIO02 state.

The codesource is available at Github.

CNC3020 milling machine arrives

in #liveupdates by Ian | 4 comments


Hacker Camp Shenzhen volume 4 was a huge success! It seemed like half the hackers were playing with CNC mills of some sort.

On the second day of camp I spent an awesome afternoon brainstorming CNC PCB making with Drew and hunting Depu market for copper clad, rivets and other parts. We also had the amazing minds of Alden and Ash providing guidance, both are involved with early reader Ril3y’s Tiny G Code interpreter and other motion control projects.

Two days ago we ordered a CNC3020 whilst at BBQ place late at night. It cost 3200 rmb all in, $530, and arrived in under 48 hours. Sjaak, Simon, and I are assembling it now and will post an update later today.

Posted in #liveupdates | 4 Comments

Home Control 2015

in Arduino, R-Pi, wireless by DP | 0 comments


Peter Scargill writes:

 If you’ve read my early blogs you’ll know I do a lot of work with a pal of mine, Aidan Ruff. We had an R&D company for years and one of our products was a home control system which was plastered all over the UK tech press at the time and loads of people loved it but it involved spouse-unfriendly WIRES – bad mistake. Well, this DOESN’T.
The two of us have been working on home control for several years and regular readers will know that in the past few months, the ESP8266 boards have turned everything around. I’ve scrapped various radio designs and gone “hell for leather” into using these boards, this original plan was with an Arduino Mega as a “master controller”. That too went out of the window when the Raspberry Pi 2 came out, dirt cheap but with more than enough power to control a house. Armed with a WIFI USB dongle, the basics of a completely wireless home control setup are now in place. Personally it could not be better timed as we’re moving house shortly and so this is an ideal opportunity to do the job properly before inflicting this on other people.

Project info at Scargill’s Tech blog.

XORLib, an open source game library for PIC32s

in library by DP | 0 comments


Shaos shared his game library for PIC32s in the project log forum:

XORLib is a simple multiplatform game library that is licensed under MIT-license and developed at least for two platforms:

  • PIC32 with NTSC and PAL TV
  • DOS with CGA/EGA/VGA

PIC32 code based on “NTSC TV interface” examples from by Bruce Land (Cornell University) that is based on some ideas from “Programming 32-bit Microcontrollers in C: Exploring the PIC32″ by Lucio Di Jasio.

XORLib is available at Github:

Via the project log forum.

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LED strip testing with Bus Pirate

in Bus Pirate by DP | 0 comments

Drew tested out some addressable RGB LEDs he bought during Hacker Camp, using a Bus Pirate.    Via Shenzhen_hacker_hole WeChat group.

The LDP6803 uses SPI for communication. A power supply and a Bus Pirate and I was able to change colors without code. The chip uses a 7bit encoding of colors so setting individual colors can’t really be done without code.


Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.

Laser etching SMT stencils tutorial

in how-to by DP | 4 comments


Felix Rusu of LowPowerLab has posted a detailed tutorial on how to laser etch SMT stencils:

In this blog post I want to show you my new method that I’ve been using since I’ve purchased a laser cutter from china. It’s using the laser to etch stencils out of transparency plastic (mylar). Chances are that you already have membership or access to a local workshop or hackerspace where a laser cutter is available, so you can give this a try. The trick is to balance the power vs speed of the laser at that sweet spot where it won’t burn the plastic or over/under etch the pads. And for those really wondering why in the world I don’t order from OSHStencils (not affiliated with OSHPark) or similar affordable online services – some of it is explained in the video but mainly because instead of waiting a few days I can do it in 5 minutes, and the flat mylar allows making letter sized stencils. Don’t get me wrong, I support and use the OSHPark PCB service but I prefer to etch my own stencils on the fly on my laser, it’s really convenient and allows for errors and retries without another few days of waiting. Plus, I can do in mylar what they can’t in thin curvy kapton.

Check out the video after the break.

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Teeny Tiny build using Bubble display and Femtoduino

in Arduino by DP | 1 comment


Phillipe Cantin published a new build:

I just received a bunch of those really cool QDSP-6064 Bubble Displays and I had to build something with them right away.
I quickly tried it using the sample code and, as I was doing that, I immediately wanted to build a small device combining this display with a femtoduino and a small LiPo battery. I ordered two Femtoduino quite some times ago but never did anything with them. I knew they would come handy one day. Then intent of this build is to eventually make something wearable.

Project info at Phillipe’s blog.

Posted in Arduino | Tagged , , | 1 Comment

Obstacle sensing walking stick for visually impaired persons

in PIC, sensors by DP | 0 comments


Avinash Gupta wrote an article detailing his smart walking stick project for visually impaired persons

This project is designed to guide a visually impaired person to walk and avoid bumping into obstacles. Low cost ultrasonic rangefinders along with a microcontroller is used to measure the distance to obstacles and if they are close enough provide a feedback to the user in form of beeps or vibrations.
The project is made on a small single layer PCB. The sensors are not mounted on the PCB but they are mounted on front of the stick and connected to the main board using wires.

Project info at Digital Wizard. Continue reading →

AVR-HV: High voltage programmer for AVR microcontrollers

in AVR by DP | 4 comments


Dilshan Jayakody writes:

 AVR-HV is high voltage parallel programmer for Atmel AVR series microcontrollers. AVR-HV allows programming, reading, verifying and configuring AVR microcontrollers with its high voltage programming interface and it connected to PC using USB interface.
In High voltage programming mode, 12V programming voltage is applied to RESET pin of target AVR microcontroller and in this programming mode user can change configuration fuses of AVR MCU with minimum amount of risk. In this programming mode target microcontroller must need to be removed from the board to reprogram.
Compare with other high voltage programming options like Atmel STK500, this programmer is simple to build, less-expensive and also easy to use with GUI application over USB interface.
Current version of AVR-HV support ATmega series AVR microcontrollers, but it can also be used with ATTiny microcontrollers which having high voltage parallel programming (HVPP) interface. To introduce new devices, only the configuration file need to be change and no source code changes are necessary.

Project info at Dilshan Jayakody’s blog and project wiki section.

Posted in AVR | Tagged | 4 Comments

Embedded Linux System

in DIY, project logs by DP | 7 comments


hak8or was inspired by Henrik’s Embedded Linux system so he made his own:

The repository is divided into two SOC’s, one being Atmel’s AT91SAM9N12 which is what the currently working board uses, and the other being Freescale’s I.MX223. Each SOC subdir contains schematics, board files, the required code modifications in the form of git patches to the secondary bootloaders, U-Boot, etc, and various scripts. The current folder structure doesn’t represent the folder structure which the scripts are run in, since this is meant solely for myself for now the most I can say is to look at the paths present in the scripts to see what script goes where.

Reddit discussion here.

Via the forum.

YOUSDR remote RTL-SDR software

Sixuniform has released YOUSDR v0.1 Alpha, an RTL-SDR webinterface for Raspian / Raspberry Pi. This is a web-wrapper for the rtl-sdr softwares. Currently it commands rtl_fm, rtl_tcp and dump1090.

The software can be downloaded from its GitHub. The instructions on the GitHub page show how to set it up on a Raspberry Pi running Raspbian, but the instructions should also be valid for other Linux distributions. As the software is new the authors are welcoming any improvements and feedback.


Bus Pirate v3.8 free PCB build

in builds by DP | 4 comments

IMG_4203 copy

kubatyszko writes, “Finally got the PCB’s and built both of them, it was a great exercise in soldering, and eye test too, especially the SMT 0603 components.”

If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever – we’ll send you a coupon code for the free PCB drawer.

Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.

Via the forum.


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Keep an eye on the sky with the Sat-light

in hacks by DP | 0 comments

In this video Chirag Nagpal demonstrates his Sat-light project, he writes:

It uses a Beaglebone Black connected to the Internet, and download TLE values of the ISS and other satellites. It then calculate the exact location of the satellites using the Python Library PyEphem. Incase one of the Satellites is hovering above, it lights up! This is how I can keep track of when I am being observed from outer space!

Project info at Chirag Nagpal’s project page.

The source code is available on Github.

Arduino-powered turntable plays moon phases

in Arduino by the machinegeek | 0 comments

While this turntable can’t play “Dark Side of the Moon”, it certainly can tell you which way it’s facing! This project by Yingjie Bei and Yifan Hu uses an Arduino to position a turntable and associated light source in such a way that the moon replica mounted on the turntable will be illuminated to demonstrate the current moon phase.

Project log and details can be found on Bei’s website.

Via Engadget.

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Free PCB Sunday: Pick your PCB

in Free PCBs by DP | 47 comments

irtoyv3-600x369 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 get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:

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Posted in Free PCBs | Tagged | 47 Comments

App note: Output capacitive load considerations

in app notes by DP | 1 comment


App note(PDF) from Murata on output capacitors loading when in a switch mode power supply

There are numerous factors to consider when adding external capacitors to switched-mode power supplies (SMPS). This article will discuss noise, startup, ESR, stability, pre-bias applications, Sense inputs, On/Off (remote enable) controls and other topics.

Many real-world DC/DC applications require external bypass “bulk” capacitors as part of the output load. These capacitors supply extra current during a step load change. Lower DC voltages used in newer logic devices mean that the voltage margin difference between logic ZERO and logic ONE is reduced to hundreds or even tens of millivolts. Thus, since even modest power supply noise can cause data errors by exceeding this threshold, these bypass caps are necessary to reduce this DC/DC noise.

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App note: EMC design guidelines

in app notes by DP | 7 comments


A great guide (PDF) to electromagnetic compatibility from Murata

International regulations regarding electromagnetic compatibility (EMC) affect many aspects of circuit and system design. However, there are many techniques that can be applied generally to reduce both the emissions from and susceptibility to, electromagnetic interference (EMI).

As a manufacturer of electronic components, Murata Power Solutions is committed to minimizing emissions from its own components and to helping its customers achieve EMC compliance by correct component choice and design. To this end Murata Power Solutions has compiled the following list of general design recommendations.

Posted in app notes | Tagged , , | 7 Comments