A signal amplifier module for HF

in DirtyPCBs.com, DIY by DP | 2 comments


Marcus Jenkins blogged about his radio frequency amplifier project he made using DirtyBoard PCB’s

In building QRP HF radios, having an RF signal level amplifier building block is handy. You want 50 Ohm output impedance, some reasonable gain, supply voltage of the usual 10-14V and ease of building using standard parts from your parts bin. Some searching around the interwebs came up with a good idea for circuit from Aaron Parks, KC8FQD, who did a YouTube video on a WWV receiver.

Via the contact form.

Arduino time lapse – camera pan device

in Arduino, DirtyPCBs.com, gadget by DP | 0 comments

time-laps-camera-pan-device (1)

An Arduino camera pan device project from Bajdi Electronics:

I own one of these small action cameras (SJcam SJ4000). I bought it because it’s small, and easy to take with you wherever you go. To make nice stable videos I mount it on a mini tripod. This got me thinking that it would be fun to have a little motor between the tripod and the camera to slowly pan the camera. That way I can make nice time lapse videos.
I happened to have a couple of 24byj48 stepper motors laying around, these little steppers motors have a gearbox and are 4096 steps for one rotation. They are pretty slow, so it’s ideal for this application. These motors are sold with a driver board that is basically an ULN2003 break out board.

Check out the video after the break. Continue reading →

Bus Pirate v3.8 free PCB build

in builds, Bus Pirate by DP | 1 comment


@kizzap88 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.

Posted in builds, Bus Pirate | Tagged | 1 Comment

Free PCB Sunday: Pick your PCB

in Free PCBs by DP | 47 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 | 47 Comments

App note: EMC tests and PCB guidelines for automotive linear regulators

in app notes by DP | 0 comments


PCB design guidelines from ON Semiconductors on minimizing electromagnetic interference (EMI) on automotive linear regulators. Link is here

Electromagnetic compatibility (EMC) is important for the functionality and security of electronic devices. Today’s designers must deal with steadily increasing system frequencies, changing power limits, high-density layouts required by more complex systems, and the ever-present need for low manufacturing cost. Therefore, it is necessary to optimize EMC.

Linear regulators supply several types of loads including microcontrollers, one of the key devices in automotive applications.

This document concentrates on EMC for automotive basic knowledge, test methods at the IC level and ON Semiconductor standards. PCB guide lines are included to prevent any board effect or external coupling.

App note: Chameleon™ technology enables low cost smart passive sensors

in app notes by DP | 0 comments


A self-calibrating sensor app note from ON Semiconductors. Link is here

ON Semiconductor’s Smart Passive Sensors powered by a Magnus®−S integrated circuit (IC) family offers the industry’s only self-tuning capability, called Chameleon technology. Implemented in an on-chip analog signal processing circuit, Chameleon technology automatically adjusts the input impedance of the IC to optimally tune the tag every time it is accessed.
Sensor tags based on conventional ICs can be detuned by a variety of external factors, most commonly by proximity to liquids or metals. Such factors can change the impedance characteristics of a tag’s antenna. When the tag’s sensor IC has a fixed impedance, a mismatch between the IC and the antenna results thus reducing the tag’s performance. Chameleon technology maintains the IC-antenna match as conditions change, resulting in more consistent sensor tag performance.

Free PCB coupon via Facebook to 2 random commenters

in Free PCBs by DP | 1 comment


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 | 1 Comment

Great results milling PCBs from Eagle with the Nomad

in Eagle, how-to, PCBs by DP | 7 comments


Liyanage over at Carbide 3D Community site writes:

Milling PCBs was one of my main reasons for getting a Nomad. I finally found some time to learn how to use Eagle and the related tools and mill my first boards. I am very happy with the results and once again very impressed by the Nomad, especially its precision.
This post provides some results and lessons learned from my first two test projects.

Details at Carbide 3D Community site.

Posted in Eagle, how-to, PCBs | Tagged , | 7 Comments

Uber home automation

in Arduino, sensors, wireless by DP | 1 comment


Eric of ElectronicHamsters wrote an article detailing his Uber home automation project:  garage door sensor, battery powered mailbox sensor or door monitor, multi sensor, laundry room washer-dryer notifier, prototype of dog tracker, garage genie and remote control, smart mouse trap.

Project info at ElectronicHamsters project page.

Check out the project instructables here.

Bus Pirate support in Python3 for I2C scripting

in Bus Pirate by DP | 0 comments


Steve aka hwstar writes, “I just wanted to let you know that I modified the python Buspirate Bitbang.py file and the I2C.py file to support Python 3.4 for a project I’m working on, and wanted to share these files with the community as they are open source. I uploaded the modified files to Github.
These files have been tested in Linux, but not Windows. The interface is the basically the same, except the result string returned is now a byte string instead of a plain string.
By modifying the Bus Pirate files to run on Python3, you get a access to a much improved tkinter code base as well as other things that Python3 has to offer.”

Via the contact form.

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

Nokia phone Arduino shield

in Arduino by DP | 0 comments


Charles Pax is making an Arduino shield for the old Nokia phone:

The cheapest and most common old phone we’ve seen is the Nokia 3100. There’s no camera, no Bluetooth, no WiFi, no frills at all. Perfect! We can pick it up in the market for just a few dollars.
This is a pretty old phone and there is no guarantee it will work on a modern mobile phone network. Our test phones are confirmed to send text messages on the China Mobile network in Shenzhen. We will have to do more tests around the world. If you have tested the Nokia 3100 or similar phone in your area, please post in the comments below.
Before we design a PCB we’ll have to determine how everything should be connected and slap it on a breadboard.

Via the contact form.

Project info at  Pax Instruments.

FM430 – A MSP430 and TEA5767 project that lets you listen to clear digital FM

in DIY, MSP430 by DP | 1 comment


From the comments on our earlier FM radio receiver post.  Rohit Gupta shows off his digital FM Receiver on MSP430 using TEA5767:

I completed one yesterday using the MSP430 and TEA5767 Chip. Gave it a minimalist switch to toggle the channels stored in an array. Gives realtime channel strength and transmission quality values too over serial.

Code is shared on Github.
Check out the video after the break.

Continue reading →

Posted in DIY, MSP430 | Tagged , , | 1 Comment

12-minute Mandelbrot: fractals on a 50 year old IBM 1401 mainframe

in programmers by DP | 1 comment


Ken Shirriff writes:

When I found out that the Computer History Museum has a working IBM 1401 computer[1], I wondered if it could generate the Mandelbrot fractal. I wrote a fractal program in assembly language and the computer chugged away for 12 minutes to create the Mandelbrot image on its line printer. In the process I learned a bunch of interesting things about the IBM 1401, which I discuss in this article.

Details at Ken Shirriff’s blog.

Posted in programmers | Tagged , | 1 Comment

#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.

Low noise amplifier – 100MHz to 300MHz

in DirtyPCBs.com, DIY by DP | 0 comments

In this video Hpux735 demonstrates his Sky67015 LNA breakout board:

A Low noise amplifier (or LNA) is a special amplifier that is designed to be the first amplifier in a receiver. It is vital that the first amplifier of a receiver has low noise, because the noise of the whole system is dominated by the first amplifier.

For more information visit the project’s Tindie page here.

CD2003 – yet another simple FM radio receiver

in DIY, hacks by DP | 7 comments


Dilshan Jayakody writes:

In last few days we are looking for some simple FM radio receiver to integrate into one of our ongoing project. For that we try several FM radio receiver ICs including TDA7000, CD2003/TA2003/TA8164, CXA1019 and KA22429. Out of all those chips we select CD2003 (or TA2003/TA8164) based receiver for our project because of its simplicity and outstanding performance. Except to CD2003, Sony CXA1019 also perform well but we drop it because of its higher component count.
We design our receiver based on Toshiba TA2003 datasheet and later we try TA8164 and CD2003 with same circuit. Either CD2003 or TA8164 can directly replace TA2003 IC, and as per our observations TA8164 gives excellent results out of those 3 chips.

Project details at Dilshan’s blog. All files are avaialble at elect.wikispaces.com.

Posted in DIY, hacks | Tagged , , , | 7 Comments

TinyK20 open source ARM debug/universal board

in ARM, open source by DP | 4 comments


Erich has posted an update on his open source ARM debug/universal board project. We wrote about it previously:

After the proof of concept phase (see “Proof of Concept: Open Source ARM SWD Debug and General Purpose Board“), the first prototypes are ready
I had the first prototypes of the board we have produced internally in my hands.
A different USB connector can be populated on the backside of the board, so it can directly be plugged into a USB port. Additionally the board can be placed into a small USB thumb drive case that way (I don’t have one for a picture now, but we use them for a different project).

Project details at MCUonEclipse project page.

Wavewatch, a soundcard oscilloscope and waveform generator

in open source, oscilloscope by DP | 4 comments

ww_gui D4p0up shared his open source soundcard oscilloscope in the project log forum:

Here is a tool that might help some of you in your DIY activities : WaveWatch, a soundcard oscilloscope 100% made with Processing.
I’ve just released the 1.3 version, making it a very credible, user friendly and totally open source alternative to existing soundcard scope systems, so that it’s worth sharing it !
It’s got all the features you’d expect from a standard scope,

  • dual channel,
  • configurable Triggering (single/Auto),
  • time and voltage measurement,
  • frequency calculation,
  • markers with delta calculation
  • voltage calibration

Project info at Banson project page. All files are available on Github.

Via the forum.

App note: Miniature motor driver resource

in app notes by DP | 0 comments


Here’s a great resources of motor drivers from Precision Microdrives. Link is here.

Whilst most DC motors are essentially driven with the same principle (by applying a DC voltage), these chips boast a host of different features. Some accept analogue inputs, others PWM or I2C, H-bridges will enable you to easily change the direction of rotation and haptic drivers are specially designed for haptic feedback applications.