Simple I2C SSD1306 driver for AVR

in AVR, library by DP | 0 comments


Jean THOMAS of TiBounise writes:

I wrote a small SSD1306 library for AVR, with a framebuffer.
It even features a small simulator to let you have a preview of what it’ll look like on the OLED screen without having to upload again and again code to your development board.

The library is released under a very permissive license, to allow people to integrate it without any constraints.

Available on Github.

Via the contact form.

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Basic Experimenter Board for rapid prototyping of electronic circuits

in dev boards by DP | 2 comments


Raj of Embedded Lab has published new project the Basic Experimenter Board for easy prototyping of electronics circuits:

Most electronics projects require some common stuff like regulated power supply, input tact switches, and output LEDs during prototyping and testing phase. Wiring these things on a breadboard for every new project could be time consuming and boring. We introduce you the Basic Experimenter Board, a general purpose develoment tool that will not only reduce the prototyping time for your next project but also free up plenty of space on the breadboard. It features regulated 3.3V and 5.0V power supply on board along with four output LEDs, four input tact switches, one output buzzer with driver circuit, a potentiometer for simulating analog input, and a 480-point breadboard for rapidly prototyping and testing your electronic circuits.

Using the Bus Pirate to see if it’s alive- TI HDC1000

in Bus Pirate by DP | 2 comments


Inderpreet of EmbeddedCode writes:

This mini article is part of a larger project an I will link to it at the end. For this project, I was required to use the TI HDC1000 and instead of buying a module, I decided to get samples and a make a PCB of my own. This would be great except I had to create the footprints which are almost microscopic! Anyways I got it made from SeeedStudios and I bought one of those ultra cheap hot air stations with no indications about temperature or airflow and some paste and got started. The reflow happened painlessly and I was pretty happy with myself. Before I move on to mounting any other parts, I decided to see if the HDC1000 was alive or had kicked the bucked in my hotair experiment.
So I started with soldering the header as well as power test pins and I hooked up the BusPirate. Har har har! I think I can explain the rest via a video and so…

Check out the video after the break.

Get an assembled Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.

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Posted in Bus Pirate | Tagged , | 2 Comments

GPS clock assembly, part III

in clock by DP | 0 comments


An update on Kevin Rye’s GPS clock project we covered previously:

I’ve been working on this clock for a long time, and a lot of effort has been put into it. I’ve learned so much from this project. I do have to admit some parts of the code aren’t as elegant as they should be, but it works. With the code complete, all that’s left to do is try my hand at designing a 3D printed joystick for the 5-way switch.

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Simple DIY lab power supply

in power supply by DP | 0 comments


Bajdi  made this DIY lab power supply and wrote a post on his blog detailing its assembly:

My DIY lab PSU has 10 binding posts in total. The ones on the left provide 12V, 5V and 3V3. The 12V output comes straight from the laptop power supply. The 5V and 3V3 are provided by a KIM055L and a KIM035L module. These can output 5A of current. The other 4 are the outputs of a LM2596-adjustable and a XL4015 regulator. The LM2596 is a simple adjustable voltage regulator board. I desoldered the trimpot and soldered a regular potentiometer to it.
The XL4015 breakout board is setup as a constant current regulator. It has 2 trimpots to set voltage and current. I again desoldered the little trimpots from the board and soldered 2 potentiometers to it. I fitted the 3 potentiometers to the front plate and added 3 nice buttons so I can easily adjust them.
The left panel meter shows the output voltage of the LM2596, the right panel meter displays the voltage and current of the XL4015 output.

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Free PCB Sunday: Pick your PCB

in Free PCBs by DP | 65 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:

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Posted in Free PCBs | Tagged | 65 Comments

App note: SD(HC)-memory card and MMC interface conditioning

in app notes by DP | 0 comments


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.

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App note: Energy Harvesting reference design user’s guide

in app notes by DP | 0 comments


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

in measurement, oscilloscope by DP | 0 comments


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.

Free PCB coupon via Facebook to 2 random commenters

in Free PCBs by DP | 4 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 | 4 Comments

Week in (p)review January 23, 2015

in week in review by DP | 0 comments


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

DIY PSU console

in DIY, power supply by DP | 0 comments


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

in builds, Bus Pirate by DP | 0 comments


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

in ARM, hacks by DP | 0 comments


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 →

Electric imp-controlled 120VAC relay switcher

in DIY by DP | 0 comments


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

in Free PCBs by DP | 0 comments

KHOS-2-3-4-5-6P 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.