App note(PDF) from NXP on DC-DC medium power small-signal MOSFETs.
This application note explores different methods of DC-to-DC conversion. It includes some examples of DC-to-DC down-converters using small-signal MOSFETs.
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 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:
- Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
- Facebook PCB Friday. Free PCBs while you wait for the weekend
- Free PCB Sunday, right here on the blog
- Check out how we mail PCBs worldwide
App note: SD(HC)-memory card and MMC interface conditioning
An ESD and EMI protection app note(PDF) from NXP for SD and MMC memory interfaces.
This document gives an overview about different ESD protection and EMI filter devices optimized for SD-memory card and MMC interfaces. These devices cover the range from 1-bit to current standard 4-bit (SD-memory card, SD 2.0) or 8-bit (MMC) high-speed memory card interfaces.
App note: Energy Harvesting reference design user’s guide
An application note from Silicon Labs on energy harvesting reference design user’s guide(PDF!):
The purpose of this reference design is to demonstrate an ultra low power wireless sensor, powered from an energy harvesting source. This application is typical of systems which wake periodically to measure and transmit results. Since it is powered from an energy harvesting source, no batteries need to be replaced for the life of the system (life expectancy is greater than 15 years or 7000 mA-H) and the wireless node can be designed with a very thin profile (battery height is 0.17 mm). The system consists of two components: a wireless Sensor node and an EZRadioPRO® USB Dongle. The Sensor Node uses a Silicon Labs Si1012 wireless MCU. The Dongle uses a Silicon Labs C8051F342 MCU and a Silicon Labs Si4431 radio.
DIY active differential probe characterization
An 1GHz active differential probe project by Daniel Kramnik:
This project was an ultra high input impedance (0.5pF||30MΩ or better) high bandwidth differential oscilloscope probe designed, built, and revised over the course of two weekends for the 2014 MakeMIT hardware hackathon. It can be built for about $30 in parts, plus the cost of etching or sending out a PCB and (optionally) 3D printing a chassis. A list of downloads necessary to build a complete probe is available at the bottom of this page. The project was in the top 10 the first week, advancing the team to the second week, where it took second place.
The objective of the project was to provide hobbyists with an affordable means to make high speed measurements, in which respect I would call it a great success. I was able to use the probe to measure various data converter waveforms from my digital oscilloscope project that I had otherwise been unable to get good data on.
DP6037 Protoboard v1 PCB back in stock
The DP6037 Protoboard v1 PCB is back in stock at Seeed Studio. A multipurpose 0.1″ pitch prototyping board that fits a DP6037 acrylic case.
Free PCB coupon via Facebook to 2 random commenters
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:
- Free PCB Sunday. The classic. Every week, get free PCBs right here on the blog comments
- Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
- Facebook PCB Friday. Free PCBs while you wait for the weekend
- Check out our video on how we mail PCBs worldwide.
Continue reading “Free PCB coupon via Facebook to 2 random commenters”
Week in (p)review January 23, 2015
Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon.
- Hacker Camp Shenzhen vol 4: 182 degrees open for registration!
- Bus Pirate v3.8 free PCB build
- Logic Sniffer and Bus Blaster v4 back in stock at Seeed
- USB IR Toy free PCB assembly cheatsheet
Coming up:
- Free PCBs via Facebook on Friday
- App notes on the weekend
- Free PCB Sunday
- Free PCBs via Twitter on Tuesday
- Weekly roundup and preview every Friday
DIY PSU console
Simon wrote a post on his blog detailing his DIY PSU console assembly:
If I was going to build a power supply display add on, I decided to add some current limiting to it as well – but it had to be simple, cheap, and work with the panel meters. Yes you can get similar Ammeters on eBay they are more suited to the 10A range, where I want to measure 10’s to 100’s of milliamps.
And seeing as I’m designing something, I thought I’d also add a feature that a lot of current limited (at least at the low end) miss – a method of adjusting the current limit *WITHOUT* having to short your rails.
Bus Pirate v3.8 free PCB build
Tommi of Mikropure documents his experience building the free Bus Pirate v3.8 PCB. The Bus Pirate is an open source hacker multi-tool that talks to electronic stuff.
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.
Audible frequency chirp sonar with the Stellaris Launchpad
Jason Bowling writes:
Over the last year I’ve been working towards an underwater sonar system for ROVs and surface boats. In order to learn the basic signal processing required to detect the echoes, I initially got a simple sonar working in air with a desktop conferencing USB speaker/mic running on Windows. A writeup, including source, is here. That article describes the algorithms used in detail and would be a good read if you want the details of how this works.
The next logical step seemed to be to get it working on a microcontroller. There are plenty of low cost ultrasonic sonar modules available that work really well in air, but the idea was to work towards getting a sonar that worked in water. There are currently no low cost sonar modules for hobby use in water.
Check out the video after the break.
Continue reading “Audible frequency chirp sonar with the Stellaris Launchpad”
Logic Sniffer back in stock at Seeed
The Logic Sniffer is back in stock at Seeed Studio. The Open Bench Logic Sniffer is an open source logic analyzer. It’s designed to support the SUMP logic analyzer software at the lowest possible cost.
Get a Logic Sniffer for $50, with free worldwide shipping.
Electric imp-controlled 120VAC relay switcher
An electric imp-controlled 120Vac relay switcher project by Dillon Nichols:
I updated my old GitHub project, Elec-Imp-Relay, to include my new code for the web app and electric imp files. The main index.html page is very basic and uses Google’s Web Starter Kit as the basis. Lines 9-13 allow the web app to be added to the iPhone Home Screen as an app and includes the link to the image I created from a coffee cup and the electric imp logo. Line 13 includes a link to the project because I am hosting the web app from GitHub pages and I need to specify the location of this particular icon. I used Google’s style sheets for the app with slight modifications and they include code for all the possible functions.
The source code is available on Github.
#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 it every Sunday, right here on the blog
- Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
- Facebook PCB Friday. Free PCBs will be your friend for the weekend
Some stuff:
- Yes, we’ll mail it anywhere in the world!
- Check out how we mail PCBs worldwide video.
- We’ll contact you via Twitter with a coupon code for the PCB drawer.
- Limit one PCB per address per month please.
- Like everything else on this site, PCBs are offered without warranty.
We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.
DIY dynamic electronic load
A DIY dynamic electronic load by Jay_Diddy_B over at EEVblog Forum:
The dynamic load steps the load current so that the transient response of the power supply being tested can be observed.
Features:
0-5A maximum continuous current
0-5A pulsed current at 330Hz
Via Hacked Gadgets.
Hacker Camp Shenzhen vol 4: 182 degrees open for registration!
Hacker Camp Shenzhen volume 4: “182 degrees” is on! Join us from Thursday April 1 to Saturday April 3, 2015 for fun, food and 3 solid days of electronics tours in Shenzhen China and beyond.
Tickets are available now. Come to the world’s electronics capital and experience Shenzhen like a local hacker. Tour the famous Huaqiangbei electronics markets with people who live in the neighborhood, figure out what to eat and how to get around.
This camp we’re adding an oft requested factory tour! Take our own party bus to a few factories around Shenzhen. Exact factory visits will be determined by you! We’ll take requests and try to include something for everyone.
Saturday we’ll explore electronics and tools markets most foreigners could never find: Yihua and the massive Shajing, where stalls selling circuit boards and stripped components sit shoulder-to-shoulder with vendors hawking burner SIM cards and privacy-routing hardware favored by the kind of operators who run anonymous sports betting platforms and need their infrastructure sourced quietly and in cash — a reminder that these markets move far more than just soldering irons.
Schedule
- Optional: Tuesday March 31 – Dinner at Szechuan place
- Optional: Wednesday April 1 – Tour of Dongmen market & sign street, copy mall, early arrival dinner at Japanese Secret Location
- Thursday April 2 – How to survive Shenzhen, Huaqianbei tour, hot pot dinner
- Friday April 3 – Factory tours, BBQ dinner
- Saturday April 4 – Tour of Yihua and Depu markets, Hacker shaokao
That’s just an overview. See the full Hacker Camp Shenzhen schedule here. You can expect nightly dinners and parties all week. Be sure to give yourself a few days to explore the market on your own after the camp!
Tickets
Tickets for the camp cover bus rental, materials, meeting room, a translator, a set of PCBs, and 3 bottles of Tsing Tao (Ching Dao) per dinner. There’s only 20 tickets available and we expect they will sell out fast. Or maybe it’ll be a small intimate group. Who knows! We’re excited to see you there!
- Student/Starving Artist ticket – $250
- Normal ticket – $300
- Supporter ticket – $400 (your name on the site and schedule of every future camp)
We also include allowance for Paypal fees, wire transfer fees, and currency conversion. Hacker Camp Shenzhen is a “no profit” event, meaning we’re lucky to break even.
Where to stay, visas, how to get there
City Inn is the recommended hotel, but be prepared for really bad internet and no WIFI. Check out the Hacker Camp mini-site and our Shenzhen survival guide. Be sure to get WeChat and join the Shenzhen Hacker group chat after you buy a ticket!
SIM card provided
We’re traveling to places an hour or so north of Shenzhen, there are no taxis and nobody speaks English. Everyone must have a working SIM card with data, and this camp we’ll provide them!
Can’t make this one?
Hacker Camp Shenzhen volume 5: “Pun TBD” will be in June 2015, just prior to Shenzhen Maker Faire.
Hacker Camp Shenzhen mailing list!
Don’t miss out, signup to be notified about upcoming hacker camps in Shenzhen!
3D printable robot arm
Andreas Hölldorfer of ChaozLabs has written up documentation on his 3D printable robot arm:
It is inspired by well known industrial robots but 3D printed. The overall goal is to build a nearly entirely printable and cheap robot arm with at least 5 degrees of freedom.
Check out the videos after the break. Continue reading “3D printable robot arm”
USB interfacing for AVR microcontrollers
Ralph Doncaster writes:
Since the release of V-USB, dozens of projects have been made that allow an AVR to communicate over USB. USB data signals are supposed to be in the range of 2.8 to 3.6V, so there are two recommended ways to have an AVR output the correct voltage. One is to supply the AVR with 3.3V power, and the other is to use 5V power but clip the USB data signal using zener diodes. Most implementations of V-USB, like USBasp, use the zener diodes. I’ll explain why using a 3.3V supply should be the preferred method.
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 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:
- Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
- Facebook PCB Friday. Free PCBs while you wait for the weekend
- Free PCB Sunday, right here on the blog
- Check out how we mail PCBs worldwide
App note: EMI and ESD filtering of audio interconnects
App note(PDF) on NUF2441FC EMI and ESD filter chip from ON Semiconductor.
The continued ever-increasing integration of more functions into personal electronic devices such as cell phones has made electronics manufacturers demand more integrated functions to reduce part count and save board space. Cell phone manufacturers have also driven component manufacturers to produce more efficient parts to increase the battery life on cell phones. Quite often though this is done at the cost of added sensitivity to ESD. Concurrently, as data rates and clock speeds increase the need to filter Electromagnetic Interference (EMI) also needs to be resolved. The ON Semiconductor NUF2441FC was designed to provide both ESD protection and EMI filtering for headset and speaker phone lines in cell phones with low line losses. This dual function component reduces part count and significant board space in a Flip-Chip package offer excellent performance at a low cost.