Serial terminal view in Eclipse Luna

in how-to, software by DP | 0 comments


Erich  writes:

I’m using mostly an external terminal program like Termite. But it is a very useful thing to have a terminal view in Eclipse so I do not need to switch to another application. All what is needed is the installation of a plugin plus the RXTX (at least on Windows). And best of all: it comes with telnet, SSH and local shell too :-)

Step by step guide at MCU on Eclipse.

ChipHeadBang – design for an USB to Serial converter with ICSP header for (slow) bitbang programming

in AVR, USB by DP | 0 comments


microtherion has published new project the ChipHeadBang, that is available on Github:

Design for an USB to Serial converter with ICSP header for (slow) bitbang programming, based on the CH340G chip.

While this seems to work pretty well, and the CH340G can be obtained extremely cheaply from sources such as AliExpress, driver support can be a bit iffy. For current versions of OS X, the vendor provided driver will cause kernel panics, and as far as I know, only this commercial alternative will work

Posted in AVR, USB | Tagged , , , | Leave a comment

Free PCB Sunday: Pick your PCB

in Free PCBs by DP | 69 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 | 69 Comments

App note: Magnetic stripe reader

in app notes by DP | 2 comments


Application note(PDF) from Silicon Labs on Magnetic stripe reader (MSR) implementation.

Magnetic stripe readers (MSRs) are widely used in many different applications such as point-of-sale terminals and key card readers. The C8051F330 is capable of integrating MSR functionality in a very small space with few external components. The high-speed, high-resolution ADC, coupled with a fast controller core makes this integration possible. This design demonstrates a two-channel MSR function using the on-chip ADC to read information directly from the magnetic read head. Output can be viewed using a PC’s terminal program via an RS-232 connection.

App note: SMBus communication for small form factor device families

in app notes by DP | 0 comments


SMBus specifications and example implementation on Silabs’ C8051F3xx and C8051F41x. App note here(PDF)

This   application   note   describes   the   SMBus specification,  how  to  configure  and  use  the  on-chip SMBus  interface,  and  SMBus  debugging  techniques. Code  examples  written  in  C  provide  the  general framework  for  most  SM Bus  Master  and  Slave implementations. An example that interfaces to a 256-byte EEPROM over a two-wire interface and supports multi-byte transfers is also included at the end of this note.

App note: A Closed-loop, wideband, 100A active load

in app notes by DP | 5 comments


A closed-loop, wideband, 100A active load (PDF!) app note by Jim Williams of Linear Technology:

Digital systems, particularly microprocessors, furnish transient loads in the 100A range that a voltage regulator must service. Ideally, regulator output is invariant during a load transient. In practice, some variation is encountered and becomes problematic if allowable operating voltage tolerances are exceeded. 100A load steps, characteristic of microprocessors, exacerbate this issue, necessitating testing the regulator and associated components under such transient loading conditions. To meet this need, a closed-loop, 500kHz bandwidth, linearly responding, 100A capacity active load is described below.
Study of this approach is prefixed by a brief review of conventional test load types and noting their shortcomings1.

Audio oscillator with frequency counter

in DIY by DP | 0 comments


Xristost blogged about his DIY Audio oscillator with frequency counter project:

After I finished the oscillator, I made some minor changes in the square signal part of the schematic. I connected five of the inverters in parallel with low value load resistors, thus reducing the influence of the parasitic capacitance of the PCB. The goal is to lower rise and fall times of square signal. Max output voltage in square signal mode is around 5V.

Project info at Xristost’s DIYfan blog.

Free PCB coupon via Facebook to 2 random commenters

in Free PCBs by DP | 7 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 →

Posted in Free PCBs | Tagged | 7 Comments

Week in (p)review April 17, 2015

in week in review by DP | 1 comment


Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon.

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
Posted in week in review | Tagged , | 1 Comment

Graphic equalizer display using ESP8266-12, MSGEQ7 and WS2812

in Arduino, LEDs, wireless by DP | 0 comments


Amir Avni made a graphic equalizer display using ESP8266-12, MSGEQ7 and WS2812:

Finally, I’ve created a this project: An equalizer display controlled by ESP8266 with the NodeMCU firmware, where the equalizer colors are controlled via WiFi

Project info at whatimadetoday site.

Check out the video after the break. Continue reading →

Easy Pulse Plugin, an Arduino pulse sensor

in Arduino, sensors by DP | 0 comments


Raj over at Embedded Lab has written an article detailing the new version of their Easy Pulse Sensor: the Easy Pulse Plugin, an Arduino and chipKIT compatible pulse sensor based on Photoplethysmography

Today we are happy to announce the release of a new addition to our Easy Pulse Sensor series named Easy Pulse Plugin. Like its predecessors, the original Easy Pulse and Easy Pulse V1.1, Easy Pulse Plugin also operates on the principle of Photoplethysmography, which is an optical technique of sensing blood volume changes in tissues by illuminating the skin surface with a light source and measuring the reflected or transmitted light using a photodetector. The photodetector output contains the cardiovascular pulse wave, which is synchronized with the beating of the heart. Easy Pulse Plugin provides all necessary instrumentation and amplification on board to detect the cardiovascular pulse signal from the fingertip. The most important characteristics of Easy Pulse Plugin is that it can be easily plugged into the left headers of Arduino Uno (or its compatible clone) board for easy interfacing, and the analog pulse signal can be fed to either A0 or A1 analog input through a 2-pin jumper selection.

Project info at Embedded Lab site.  It’s also up on Tindie.

Yet another Bus Pirate free PCB build

in builds by DP | 0 comments


Jason Mann built a free Bus Pirate v3.8 PCB.   The Bus Pirate is an open source hacker multi-tool that talks to electronic stuff.

I received my free PCBs from #dangerousprototypes at the end of last month. I quickly put them together, but I ran into problems programming the bootloader and firmware. I finally managed to get around those problems and find out that the +Cypress Semiconductor CY7C65213 is a drop in replacement for the FTDI FT232RL that Dangerous Prototypes recommends.

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.


Details can be found on Jason’s g+ page.

Bus Pirate v3.8 free PCB build

in builds by DP | 0 comments


jure94 built a 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.

Via the forum.

Posted in builds | Tagged | Leave a comment

DIY ESP8266 Development Board

in DIY by DP | 8 comments


A DIY ESP8266 Development Board from Electro-Labs:

In this project, we are building an ESP8266 Development Board which lets the user make connection to ESP8266 from a PIC microcontroller and a PC. The board also provides all the needs to be used as microcontroller peripherals such as LCD display, pusbuttons, indicator LEDs and GPIO extension. The PC connection is done by the help of FT232RL USB-UART converter over a Mini-USB connector. Since the PIC microcontroller used is a 5V chip, 5V-3.3V bi-directional level converter circuits are also included on the board.

Project info at Electro-Labs.

Posted in DIY | Tagged , | 8 Comments

#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.

DoorBell + Moteino = Awesome

in DIY, hacks by DP | 0 comments


Felix of LowPowerLab has written an article detailing his DIY Moteino DoorBell:

A lonely doorbell activated by a boring push-button at the front door is not very exciting in a world of Arduino and “Internet of Things”. I’ve been wanting to Arduinize the doorbell into the Moteino Framework gateway interface so that I could:

  • observe/count/graph when the doorbell is used
  • get notified when someone rings it if I am not at home (email, SMS etc)
  • play a sound when I am in my lab where I have a hard time hearing the chime (did I hear it or not? should I go upstairs to check? nah… I’m too lazy busy for that)
  • ring the bell if I want to, *remotely* from your mobile device (why not right? just detecting is too boring)

Project info at LowPowerLab.

Drive an old laptop display from an AVR

in AVR by DP | 0 comments


Jean refers us to this article by Eric Wazhung  about interfacing LVDS displays using an 8-bit AVR:

Different displays have different (undocumented) functionality. With the several I’ve tested, I’ve attempted to create a step-by-step procedure to get a new display going (or find out early-on if it’s not possible. So far I haven’t run into one that couldn’t be coaxed into working with this system).
Several of the tested LVDS displays were removed from old 12in G3/G4 iBooks. Two revisions of the same Samsung model, a Chi-Mei, and a Boe-Hydis have been tested. All are pretty standard laptop TFTs: 1024×768, FPD-Link/LVDS single-channel, DE-Only displays. (The code is written to work with non DE-Only displays–those that pay attention to the H-sync and V-sync signals–but this is untested.)
Each display has its quirks and its benefits.

Check out the video after the break.

Via the contact form. Continue reading →