Categories

Bus Pirate v3.8 free PCB build

Posted on Monday, March 13th, 2017 in builds, Bus Pirate by DP | No Comments

1FreePCBbuild

@kevinneubauer tweeted picture of his free Bus Pirate v3.8 PCB build. 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.

Analog Discovery USB isolation

Posted on Monday, March 13th, 2017 in hacks by DP | No Comments

 

pics-DSC_8393-600

Bob writes:

Back when I was deverloping the PSU burner, I wanted to have the Analog Discovery isolated from the common ground, to avoid noise and other issues. Since I did not have a way to do this, I ended up using a laptop on battery for measurements. But for long term, I needed to have this isolation. Unfortunately, things that can isolate USB at 480Mbps or faster are too expensive to justify.
The solution
The ADUM3160 isolator can provide a magnetically isolated 12 Mbps connection, which proved to be good enough. I grabbed one ready made isolator module from ebay for about $12, cheap enough. Well, it is not perfect: the B0505S DC/DC converter provided can only supply 1W and the Analog Discovery is a hungry beast.

More info at Electrobob.com.

Free PCB Sunday: Pick your PCB

Posted on Sunday, March 12th, 2017 in Free PCBs by DP | 26 Comments

BP-600x373

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:

(more…)

App note: Selecting coupled inductors for SEPIC applications

Posted on Sunday, March 12th, 2017 in app notes by DP | No Comments

an_coilcraft_doc639

Application example from Coilcraft on how coupled inductors gain advantage over separately wound inductors, calculations included. Link here (PDF)

The SEPIC (Single-Ended Primary Inductance Converter) topology is used in applications that require characteristics of both a buck and a boost regulator, specifically the ability to step up and step down the input voltage. Most often operated in CCM (Continuous Conduction Mode), SEPIC provides a non-inverted output voltage.

Typically, SEPIC is used in battery operated systems and automotive applications. In these applications, the battery input voltage, or bus line voltage, may be greater or less than that of the desired output voltage, depending on the charge state of the battery. The SEPIC topology can operate over more of the battery discharge cycle because of the ability to regulate the output voltage over a wider input voltage range, including above and below the output voltage.

The selection of one coupled inductor over two single parts saves board space and can also save cost.

App note: Choosing inductors for energy efficient power applications

Posted on Sunday, March 12th, 2017 in app notes by DP | No Comments

an_coilcraft_doc1400

Designing efficient power converters guide from Coilcraft. Link here (PDF)

In high frequency DC-DC converters, inductors filter out the AC ripple current superimposed on the DC output. Whether the converter steps the voltage down – buck – or steps the voltage up – boost – or both up and down – SEPIC, the inductor smooths the ripple to provide a pseudo-DC output.

For battery powered applications, battery life is extended by improving the efficiency of the entire power supply circuit, and inductor efficiency is often a major consideration in the design. Careful consideration of inductor efficiency can mean the difference between having your battery work when you need it and having to stop in the middle of an important task to plug it into a charger.

Inductor efficiency is highest when the combination of core and winding losses are the lowest. Therefore, the goal of highest efficiency is met by selecting an inductor that provides sufficient inductance to smooth out the ripple current while simultaneously minimizing losses. The inductor must pass the current without saturating the core or over-heating the winding.

Teardown and review of the new MHS5200A

Posted on Friday, March 10th, 2017 in Teardowns by DP | No Comments

Craig writes:

I’ve gotten a lot of questions on the blog about the new version of the MHS5200A function generators available on eBay. Viewer Tolga was kind enough to send one in to me to review and tear down. Although some improvements have been made over the older models, there are some concerning issues with these new models too!

More details at Analog Zoo homepage.

Free PCB coupon via Facebook to 2 random commenters

Posted on Friday, March 10th, 2017 in Free PCBs by DP | No Comments

BP

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:

(more…)

Hacking the DPS5005

Posted on Friday, March 10th, 2017 in hacks by DP | No Comments

pics-OpenDPS-600

Johan Kanflo’s OpenDPS project, a free firmware replacement for the DPS5005:

This write up of the OpenDPS project is divided into three parts. Part one (this one) covers reverse engineering the stock firmware and could be of interest for those looking at reverse engineering STM32 devices in general. Part two covers the design of OpenDPS, the name given to the open DPS5005 firmware. Part three covers the upgrade process of stock DPS:es and connecting these to the world. If you only want to upgrade your DPS you may skip directly to part three.

More details at Johan Kanflo’s blog.

Cheep Mod II – a low cost platform for Euro-Rack digital audio

Posted on Friday, March 10th, 2017 in ARM by DP | No Comments

pics-cheep2-600

Eric Brombaugh writes, “This is a small 6HP Euro-Rack format module with 3 CV inputs, 3 pots, Digital (Sync) input, 16-bit stereo audio outputs. It’s a slight modification of the Cheep Mod I did earlier, but with a slightly more advanced MCU that provides I2S output and has more on-chip flash. One of the goals here was to test out the audio characteristics of one of the low-cost I2S DACs that are cropping up.”

Project info at Eric Brombaugh’s blog.

 

Esp8266 WebServer farm

Posted on Wednesday, March 8th, 2017 in wireless by DP | No Comments

20150508_171952

An Esp8266 WebServer farm project by Eldon Brown’s (a.k.a WA0UWH)

After several long months, I have reactivated my Esp8266 WebServer Farm.
Currently, one of my WebServers can be accessed as: esp.wa0uwh.com:8154

More info at WA0UWH homepage.

Temperature controlled etching bath with magnetic stirrer

Posted on Wednesday, March 8th, 2017 in DIY by DP | No Comments

2013-05-02_23-49-26

Michael writes, “Yet another temperature controlled etching bath for producing PCBs at home. But this one has a magnetic stirrer :)

Check out the video after the break.

Project info at acidbourbon’s blog.

Via the contact form.

(more…)

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, March 7th, 2017 in Free PCBs by DP | No Comments

IRToy-600x369

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.

Datum/Symmetricom 8040 Rubidium frequency standard teardown

Posted on Tuesday, March 7th, 2017 in Teardowns by DP | No Comments

pics-8040_int-600

Teardown: A look at the Datum/Symmetricom 8040 Rubidium frequency standard

The 8040 used an LPRO 101 (low profile Rubidium oscillator) oscillator. Interestingly, there is a note written on the top of the LPRO case: “vibration test may have magnetized cover”. As you may know, Rubidium standards’s accuracy is very sensitive to external magnetic field. But it shouldn’t be an issue for me as the drift caused by magnetism is usually in the sub milli-Hertz range and even the most sensitive frequency counter in my lab won’t be able to pick up this minute drift.

More details at Kerry Wong’s blog.

Check out the video after the break. (more…)

Tiny ESP8266 Breakout Board

Posted on Tuesday, March 7th, 2017 in DirtyPCBs.com by DP | 1 Comment

breakout-top

Stavros made a very small ESP8266 breakout board:

A very small breakout for the ESP8266. Includes all necessary pullups/pulldowns for it to boot to your code, a LDO regulator, a 3V3 output pin and enough breadboard space for one row on each side on a standard breadboard.

Full details on Github. Boards DirtyPCB order link here.

Keysight MXA revision-b signal analyzer / Spectrum analyzer review, analysis & experiments

Posted on Monday, March 6th, 2017 in Teardowns by DP | No Comments

Keysight

Keysight MXA revision-b signal analyzer / Spectrum analyzer review, analysis & experiments from The Signal Path:

In this episode Shahriar reviews the long awaited Keysight MXA Signal Analyzer (N9020B). The new X-Series Spectrum Analyzers from Keysight offer an entirely re-designed GUI interface which supports multiple tabs as well as multi-touch interaction.

Check out the video after the break. (more…)

Free PCB Sunday: Pick your PCB

Posted on Sunday, March 5th, 2017 in Free PCBs by DP | 22 Comments

BP-600x373

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:

(more…)

App note: ASIC fixes for noisy analog “Oops”

Posted on Sunday, March 5th, 2017 in app notes by DP | No Comments

an_maxim_an5554

App note from Maxim Integrated about simple fixes that can solve most issues when designing with ASICs. Link here (PDF)

Noise is a common problem in mixed-signal ASICs, degrading performance and jeopardizing the completion of products. This application note gives hints and tips for adding external circuits that make many of these ASICs operational for prototyping or shippable as final products. Ways to optimize the ASIC by correcting noise in analog circuits, making adjustments, calibrating gain and offset, and cleaning power sources are discussed. The payoff is quicker time to market and even the prevention of an extra ASIC manufacturing spin.

App note: Multiplex boosted class-D without additional external circuitry

Posted on Sunday, March 5th, 2017 in app notes by DP | No Comments

an_maxim_an5792

An analog switch MAX14689 from MAXIM Integrated let signals that are higher than rail voltage pass. Link here (PDF)

Boosted class-D amplifiers drive speakers with voltages greater than the supply voltage. These amplifiers are becoming more common because they allow higher performance audio from a single lithium ion battery. Most boosted class-D amplifiers, however, do not give the user access to the internal boosted voltage. This makes it difficult to multiplex a speaker to multiple audio sources using common analog switches. This application note discusses how the Beyond-the-Rails capability of the MAX14689 allows it to switch these signals without additional circuitry.

Bus Pirate v3.8 free PCB build

Posted on Saturday, March 4th, 2017 in builds, Bus Pirate by DP | No Comments

Pics-FreePCB-C2vAKP8WgAE1twU-600

@incyi tweeted picture of his free Bus Pirate v3.8 PCB build. 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.

Remote jamming “detector” on the cheap

Posted on Saturday, March 4th, 2017 in security by DP | No Comments

pics-IMG_8207-600

Andrew blogged about his cheap car remote jammer ‘detector‘:

There are a number of ‘detectors’ available but the prices range from about R500 to over a few thousand! Generally these simply determine if there is a signal being transmitted for an extended period of time, and if there is it will sound an audio or visual (usually LEDs) alarm.
Having worked with 433mhz transmitters and receiver pairs for some of the research I did previously on bypassing car remotes as well as building the zacon badges I thought I would give it a go to build a very cheap passive ‘detector’. I put detector in quotes because it still needs a person to visually see the alert!

More details at AndrewNohawk blog.

Check out the video after the break. (more…)

Next Page »« Previous Page

Recent Comments

  • Jeff Tee: Still in the race?
  • Barry: Maybe not to late Need new project Free PCB Sunday
  • Sorin: I'll like one. Will save some time in producing myself.and your might have a better quality.. next project bus pirate!!!
  • Larry Couvillion: Please oh please oh pretty please!!!!
  • Ben Laskowski: Yes please!