DIY ez-FET lite…ghetto style

in DIY, MSP430 by DP | 2 comments


Juan Ignacio has published a new build, a DIY ez-FET lite:

I have a few MSP430G2955 around but non of my Launchpads are capable of programming this MCU. Texas Instruments released a while back all the informtation needed to build the new ez-FET lite. The eZ-FET lite is a low cost USB-based on-board emulation solution for MSP430 microcontrollers. This debuger supports all MSP430 devices compatible with SBW programming and I could use it to program the MSP430G2955.
The hardware is based on an MSP430F5528 and I used a QFN version with an adapter board

Project info at ssihla site.

Posted in DIY, MSP430 | Tagged , | 2 Comments

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:

Continue reading →

ZFM-20 fingerprint capture library

in library by DP | 1 comment


Dilshan Jayakody  writes:

This ZFM-20 fingerprint library is developed to capture and retrieve fingerprint images from the above sensor module. The main purpose of this library is to use ZFM-20 sensor with PC as low cost fingerprint capture unit and because of that, in-module fingerprint processing and verification functions are not implemented in this library.
ZFM20-LIB is x86 native shared library and its implemented using Lazarus/FPC. This library is developed to use with most of the programming languages which including C, C++, Delphi, FPC, Microsoft .net framework based languages, etc. Object oriented wrappers for this library are available for both .net framework support languages and for FPC.
This version of ZFM-20 Fingerprint capture library is tested with ZFM-20 series serial fingerprint module with CH340G USB to serial converter. Generally this library is design to work with any USB to serial converter which including FT232, CP2101, etc.

The library is hosted on Github.

More details at Jayakody’s blog.

Posted in library | Tagged , , , , | 1 Comment

A homebrew Simpleceiver project

in DIY by DP | 0 comments


Pete Juliano, N6QW, has been working on a DIY Simple-ceiver project. He writes:

Today I finished what I call the main board which is comprised of the Mixer stage (SBL-1) followed by the 1st IF Amplifier which is a 12 MHz design consisting of two J310 JFETS configured as a Dual Gate MOSFET. The board also contains the new 4 pole Crystal Filter followed by the 2nd IF AMP stage which is similar to the 1st IF Amp. Below is a photo of that board. I have tried to label the various sub-circuits so you can see the layout. The “squares” are 2/10 inch. The W1REX MePads would work ideal for this board.

Project info at Pete N6QW blog.

Check out the video after the break. Continue reading →

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Macbook charger teardown: The surprising complexity inside Apple’s power adapter

in Teardowns by DP | 0 comments


A teardown of a Macbook charger by Ken Shirriff:

Have you ever wondered what’s inside your Macbook’s charger? There’s a lot more circuitry crammed into the compact power adapter than you’d expect, including a microprocessor. This charger teardown looks at the numerous components in the charger and explains how they work together to power your laptop.

More details at Ken Shirriff’s blog.

ESR measurement using multimeter and function generator

in how-to, measurement by DP | 0 comments


Kerry Wong has written an article discussing the measurement of capacitor ESR using a multimeter and a function generator:

Capacitor ESR (Equivalent Series Resistance) measurement is very useful in diagnosing issues with power supplies. In linear power supplies, a high ESR filter capacitor may cause excessive ripple current on the voltage rails and can cause the capacitor to overheat due to its increased resistance. In low dropout linear supplies, the ESR of the output capacitors affect the loop stability and excessive ESR in these output capacitors can make the power supply unstable, which in turn can lead to out-of-tolerance voltage being applied to the load and could cause future damages. In switching mode power supplies, the ESR of capacitors are even more critical. In this blog post I will discuss how to measure the ESR of a capacitor using a function generator and a multimeter. A short video on this topic is also included towards the end.

More details at Kerry Wong’s blog.

Check out the video after the break.

Continue reading →

#FreePCB via Twitter to 2 random RTs

in Free PCBs by DP | 0 comments


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.

Teledyne LeCroy factory tour

in Videos by DP | 0 comments

Factory tour video of the Teledyne LeCroy factory in  in Chestnut Ridge, NY by Sebastian (a.k.a KF5OBS):

Quick look both at & inside the brand new Tektronix TSG4106 6 GHz vector signal generator. They say real beauty lies on the inside and this beauty certainly measures up, inside and out.

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Hong Kong/China dual number data SIMs with quality internet

in Shenzhen by DP | 3 comments


Cross boarder SIM cards from China Mobile and China Unicom promise a single SIM that works in Hong Kong and China. Mobile data networks exit at the SIM card home location, so that means Hong Kong internet while in China. These SIMs are sold by two of China’s biggest state owned phone companies, they’re totally legit.

I’ve been skeptical of the cross border SIM cards because China Mobile 3G and 4G doesn’t work with many phones from outside China. Recently I reread an article posted in the Shenzhen_Hacker_Bei WeChat group and was surprised to see that my Samsung S6 dual SIM phone supports the China bands (TDD-LTE on bands 38, 39 and 40). Today I’m in Hong Kong today with no other mission, so let’s go to Aplui street market and try them all. Sham Shui Po, exit C2. Walk forward one block to the phone card booths.

Continue reading →

Posted in Shenzhen | Tagged , , | 3 Comments

Making PCB vias with conductive ink

in PCBs, tutorials by DP | 0 comments


Here’s an alternative method for making PCB vias using conductive ink from Diyouware:

We developed an alternative method for making PCB vias through-hole using our robot.
As you probably know the traditional DIY method consists in threading a wire through the holes and then soldering it and then cutting it off. For example, if we have 100 vias in our PCB, we have to insert the thin wire on each hole, cut it and solder it 200 times. This is time-consuming, but also tedious, absurd, prone to failures and produces a melancholic state of mind.:-)
So we decide to innovate in this area developing a new method which consists in drilling blind vias instead of holes and filling them with conductive ink.

More details at Diyouware blog.

Check out the video after the break. Thanks Diyouware team for using DP sticker!

Continue reading →

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Seeed Studio’s Annual Big Sale Holiday: Seeeday!

in News by DP | 0 comments


Huge saving @ Seeeday! Collect Seeeday coupons for $0 shopping:

Seeeday comes from word “Seeed Day”. It is Seeedstudio’s special sale holiday, and it is a one day only event that takes place on the second Wednesday of December every year. It will be on December 9th this year. We offer screaming deals on various items on whole site.

Part 1:  Buy more, get more Seeeday Coupons (Nov. 23 – Dec. 7, 2015 EST)
Part2:  Crazy Flash Deals (Nov. 26, Nov. 27 and Nov. 30
Part3:  $0 Shopping with Seeeday Coupons on Seeeday! Let’s rock Seeeday!

Visit Seeed Studio’s promo page for details.

App note: Protecting the Universal Serial Bus from over voltage and overcurrent threats

in app notes by DP | 0 comments


An old application note from Littelfuse about USB protection. Link here (PDF)

This application note addresses the various requirements for protecting the Universal Serial Bus (USB) from overcurrent and overvoltage environmental threats. The solutions presented cover both USB 1.1 and the higher speed USB 2.0 circuitry. Specific emphasis is placed on USB 2.0 with information directed at hot connection over current conditions and electrostatic discharge (ESD) induced in the USB system.

Free PCB Sunday: Pick your PCB

in Free PCBs by DP | 46 comments


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:

Continue reading →

Posted in Free PCBs | Tagged | 46 Comments

App note: Automotive circuit protection using Littelfuse automotive TVS diodes

in app notes by DP | 0 comments


An interesting app note from Littelfuse about automotive circuit protection but also discusses about where transients came from in an automotive setup. Link here (PDF)

The designers of automotive electronics face many technical challenges during the system design process, including designing methods of protection against a variety of electrical hazards. The three major sources of electrical hazards in these systems are electrostatic discharge (ESD), lightning, and switching loads in power electronics circuits. Overcoming transient surges that can harm the vehicle’s electronics is one of the biggest challenges of the design process.

Protecting automotive electronics includes eliminating transient surges that can damage the control units, infotainment electronics, sensors, fuel injectors, valves, motors, 12/24/42/48V powertrains and hydrolytic controllers, etc.

App note: AVR32 UC3 USB host mass storage bootloader

in app notes by DP | 0 comments


USB host mass storage bootloader (PDF!) app note from Atmel:


• In-System Programming (ISP) and Field Upgrade
– Configurable Start Condition with an Upgrade Firmware File ‘avr32fwupgrade.uc3’
Located on a USB Device Implementing the USB Mass Storage Class
• USB Protocol
– Based on the USB Host Mass Storage Class (MSC)
• USB MSC bootloader is additional to the pre-programmed USB Device Firmware
Upgrade (DFU) bootloader
• No computer required

Vocoder encoder relay board

in DIY by DP | 1 comment


Jaanus published a new build, a vocoder encoder relay board:

I designed couple of vocoder encoders. Vocoders are devices that encode sound by chopping it up by frequency bands and express each frequency band only by its amplitude. This kind of representation allows to mix all the frequency bands with each other. This have been used as a method of speech encryption in the past. I build one part of the system – relay board that took analog voltages and mixed them up with each other to provide encoding/decoding.

All source files are available at Github.

Posted in DIY | Tagged , | 1 Comment

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:

Continue reading →

Rigol DSA875-TG 9kHz – 7.5GHz Spectrum Analyzer & tracking generator review, teardown & experiments

in Teardowns by DP | 0 comments

Rigol DSA875-TG 9kHz – 7.5GHz Spectrum Analyzer & tracking generator review, teardown & experiments from TheSignalPath:

In this episode Shahriar takes a close look at the top-of-the-line Rigol DSA875-TG 7.5GHz Spectrum Analyzer. This unit which, offers a built in tracking generator for the full frequency range, has a portable form-factor. I offers the following performance:

  • 9 kHz to 7.5 GHz Frequency Range
  • Typical -161 dBm Displayed Average Noise Level (DANL) normalized to 1 Hz
  • -98 dBc/Hz @10 kHz offset Phase Noise
  • Total Amplitude Uncertainty <0.8 dB
  • 10 Hz Minimum Resolution Bandwidth (RBW)

The unit is tested against linearity specification as well as overload conditions. The phase noise of the unit is also verified with an external Keysight synthesizer. The instrument is used to measure OIP3, P1dB input and output matching of various amplifiers. The tracking generator is also used to measure gain and switching behavior of a WiFi extender module. The built-in functions are used to measure OBW, channel power, ACP and THD. The teardown of the unit is also presented showing excellent build quality and manufacturing.

Via TheSignalPath.

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Global Geek Tour mini site with maps, comments, resources

in Global Geek, site by DP | 0 comments


Geek tourism is a thing. Travel somewhere new, eat the food, drink the beer, and check out the local hacker scene. In Shenzhen we see 5 or 6 visitors a week. Whether a side trip to Akihabara, or a full on expedition through Huaqiangbei, don’t leave home without bookmarking the Geek Tour mini site.

Maps of each market help get you oriented. Use the icon in the upper right to show the location of market stands, transit, and food. Read comments on each place, or leave your own. Don’t worry, the maps come from Open Street Maps so they even work in China! If your mobile browser supports HTML5 you will see your own geolocation on the map.

Via the forum.

Posted in Global Geek, site | Tagged , | Leave a comment