Free PCB Sunday: Pick your PCB

Ethernet LED driver

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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What is tomographic motion detection?

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Recognizing the shortcomings of traditional PIR and ultrasonic sensors used in alarm systems, security researcher Connected Ape decided to explore other options. He discovered this patent for a mesh system of RF nodes, designed to detect the presence of humans based on changes in the baseline signal strength between nodes. While such commercial systems are more costly, their advantage is the ability to pass through walls, furniture and other obstructions. This principle is implemented using signals in the 2.4 GHz range, and is found in systems such as those from Xandem which use the TI CC2540 RF SoC.

You can find more information and links in the post at Cybergibbon’s blog.

App note: Understanding common-mode signals

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Here is a tutorial from Maxim on common-mode signals.

To understand how common-mode signals are created and then suppressed, you should first understand the interaction of shields and grounds in common cable configurations. The following discussion defines a common-mode signal, reviews the common cable configurations, considers shielded vs. unshielded cables, and describes typical grounding practices. The article discusses methods whereby common-mode signals are created and rejected.

The primary focus of this discussion is on RS-485/RS-422 cables and signals, but the discussion also applies to telephone, audio, video, and computer-network signals.

Miniscope v2d: STM32 oscilloscope and arbitrary waveform generator

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Tomeko has posted an article describing miniscope v2d integrated arbitrary waveform generator:

Cheap low-speed dual channel PC/USB oscilloscope and arbitrary waveform generator with STM32F3 microcontroller.
Miniscope v2d is based on STM32F303CBT6 microcontroller – LQFP48 device from STM32F3 family featuring:

  • 32 kB RAM on data bus
  • 8 kB RAM on instruction bus
  • 128 kB FLASH memory
  • USB device (full speed)
  • 4 fast and flexible ADCs
  • 12-bit DAC with two output channels
  • 4 opamps that can work in PGA mode
  • ROM bootloader with USB DFU option available

Check out the video after the break.

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Free PCB coupon via Facebook to 2 random commenters

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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. More PCBs via Twitter on Tuesday and the blog every Sunday.

Don’t forget there’s free PCBs three times every week:

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Open SmartWatch Project: Arduino tool chain (alpha)


We recently posted about the Sony Open SmartWatch project. Since then, Arduino enthusiasts and Sony have been working on a proof of concept for how SmartWatch could be setup to work in an Arduino environment. As a result of these efforts, the Arduino crew have published a GitHub project that includes an alpha version of a complete tool chain, including the Arduino IDE. This will allow developers to innovate with SmartWatch on top of Arduino’s toolchain. Learn more on the Sony developer’s site.

Week in (p)review June 21, 2013

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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
  • 3D model on Monday
  • Eagle parts and tips on Tuesday
  • Free PCBs via Twitter on Tuesday
  • A new tutorial on Wednesday
  • Workshop video on Thursday
  • Weekly roundup and preview every Friday

Propeller Mini

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Parallax has introduced a smaller version of the Propeller P8X32A-M44 multi-core MCU dev board. Known as the Propeller Mini it has the same specs as the original Propeller board, but with 19 IO pins on a board measuring 20.5 X 38.6 mm. The board can be powered by 6.5 to 12 volts on Vin, and IO pins are accessible via through hole solder tabs. It retails for $24.99.

For more details, visit the Parallax Propeller Mini page. or download the product spec sheet.

OpenSprinkler, an open-source internet-based sprinkler / irrigation timer

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Ray has written a detailed article about his OpenSprinkler 2.0 Arduino-based irrigation controller:

OpenSprinkler is an open-source Internet / Ethernet sprinkler timer / controller based on the Arduino platform. It works with standard 24VAC sprinkler valves commonly found in household watering and irrigation systems. You may be planning to buy or have already purchased a commercial sprinkler timer / controller, but chances are that these systems provide a limited set of fixed functionality, and have no web scheduling and monitoring capability. These limitations are the main motivations for this open-source project.

DigiX – The ultimate Arduino compatible board with WiFi

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Ihsan informs us of Digitstump’s inexpensive, powerful Arduino-compatible board with WiFi – the DigiX:

Have you seen this DigiX board by Digistump? They are the ones who created the Digisparks as well. As a difference from Digispark, this time they are aiming high end region of the devboards.

DIY servo tester based on ATTiny85

servotesterfront

Trandi made this simple  DIY Servo tester based on ATTiny85:

I had to test a RC speed controller that I wanted to use to control an electric car window motor, and for the 100th time I was facing the same dilemma: find 8 batteries for my remote control, dismount the RX part from the quadcopter and use that, OR grab the Arduino and write quickly some code to generate the corresponding signals? Neither of which was actually particularly handy…  So I finally decided to build a small stand alone servo tester.

BotQueue open source 3d printer over web control software

botqueue
Developer Zach Hoeken and his friends at BotQueue have released the code for their software which allows 3D printer conrol over the internet. They call it BotQueue.

BotQueue lets you control multiple 3D printers through the Internet and turn them into your own manufacturing center. Think cloud-based computing, but for making things in the real world. Now you can build the robot army you’ve always dreamed of! Oh yeah, and its 100% open source because that’s how I roll.

Project details, code downloads and more information can be found at Hoektronics.

RoboRoach helps you control a living insect from your smartphone

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The RoboRoach: Control a living insect from your smartphone! by Backyard Brains

This is one of the most incredible kickstarter campaign ever

Control the movements of a live cockroach from your own mobile device! This is the world’s first commercially available cyborg!

Via Open Electronics.

USB Tester and Sick of Beige

USB_Tester_SOB_5031

MobileWill shows off his USB Tester in a Sick of Beige (DP5031) case :

From the beginning I designed the USB Tester to use the Dangerous Prototype Sick of Beige (SOB) standard PCB sizes. 50x31mm being the smallest rectangle and most ideal for the USB Tester. One of these reasons was that in doing so it would fit their standard acrylic cases which can be found at Seeedstudio.com for $3.

Sick of Beige basic case v1 (DP5031)  is available at Seeed for $3.

Autonomous car build

Jason Dorweiler blogged about his autonomous car build:

For the localization of the car I’ll be using a GPS sensor and accelerometer. First, the GPS will find the starting coordinates of the car. Then the car will start moving, somewhat blindly at first. Once the car is moving, data from the accelerometer and elapsed time can be used to calculate the velocity of the car. These two measurements are then passed into a Kalman filter to improve the accuracy of the car’s position.

At the same time, heading data from the GPS and gyroscope are passed into another Kalman filter to get an accurate heading on the car. The position and heading data from the Kalman filters is then compared to a GPS waypoint given to the sensor and motor control. Next, a heading toward the desired GPS waypoint is calculated, and the appropriate signal is sent to the steering servo in order to point the car in that direction.

Via Hacked Gadgets.

Check out the video after the break.

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