hlipka posted picture of his free cable build. The Premium Make Your Own Cable Kit contains enough connectors to make an (almost) lifetime supply of cables for standard 0.1″ (2.54mm) headers.
Via the forum.
KeySweeper – covert Microsoft wireless keyboard sniffer using Arduino and nRF24L01+
Samy Kamkar has written an article detailing the build of his KeySweeper project:
KeySweeper is a stealthy Arduino-based device, camouflaged as a functioning USB wall charger, that wirelessly and passively sniffs, decrypts, logs and reports back (over GSM) all keystrokes from any Microsoft wireless keyboard in the vicinity.
All keystrokes are logged online and locally. SMS alerts are sent upon trigger words, usernames or URLs, exposing passwords. If unplugged, KeySweeper continues to operate using its internal battery and auto-recharges upon repowering. A web based tool allows live keystroke monitoring.
Files and source code available at Github.
Project info at Samy’s project site.
Low power magnetic hold and release mechanism
This video by Shane Ormonde discusses the low power magnetic hold and release mechanism:
With the inductor and magnet combined, ferrous metal objects can be held without any power indefinitely. To release the metal object the magnetic field holding it up needs to be temporarily cancelled out. This happens by pulsing current through the inductor which generates a magnetic field separate to that of the magnet. These two magnetic fields are of the opposite polarity meaning the inductors field cancels out the magnets field. The inductor only has to be powered long enough for the item to drop which I haven’t measured but its probably somewhere in the hundreds of milliseconds lets say around 100 milliseconds at a guess. This means you can hold an object for potentially a very long time (months, years maybe I dunno!) and expend a relatively small amount of power releasing it compared to if you’d used an electromagnet to hold the thing up which required a constant power source.
Details at Wattnotions.
AVR timer-based one shot explained
Josh writes:
Last time, we made one-shot pulses using the AVR’s built in hardware timer module. Today we are going to dive deep into the datasheets to see how this technique is able to coax the normally free-running timer into generating a single pulse. Along the way, we will learn about the low level rules that govern the operation of the timer, and use a trick or two to get around those rules. Read on!…
Project details at Josh’s site.
App note: Low pin-count LCD interface
Back to basic LCD interfacing app note(PDF!) from Silicon Labs.
This application note provides an example interface for a C8051F330 device with an example LCD. First, this application note describes how an LCD works and then describes the two types of LCDs: direct drive and multiplexed drive. Next, the software interface and structure are explained. Finally, this note describes how to modify the software example to work with other LCDs.
The code accompanying this application note was originally written for C8051F33x devices. The code can also be ported to other devices in the Silicon Labs microcontroller range.
Free PCB Sunday: Pick your PCB
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:
- Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
- Facebook PCB Friday. Free PCBs while you wait for the weekend
- Free PCB Sunday, right here on the blog
- Check out how we mail PCBs worldwide
App note: Advanced Encryption Standard (AES) implementation on C8051F326/7 devices
An AES implementation on Silicon Labs’ C8051F326/7 microcontrollers app note(PDF!)
The Advanced Encryption Standard (AES) is an algorithm used to encrypt and decrypt data for the purposes of protecting the data when it is transmitted electronically. The AES algorithm allows for the use of cipher keys that are 128, 192, or 256 bits long to protect data in 16-byte blocks.
The purpose of this application note is to provide a sample implementation of the AES algorithm for Silicon Labs microcontrollers and to detail the performance of the implementation. The provided example code is intended for
C8051F326/7 devices, but, since the code is not hardware-specific, it can easily be ported to any Silicon Labs microcontroller.
App note: Designing efficient digital up and down converters for narrowband systems
An app note (PDF!) from Xilinx on designing efficient digital up and down converters for narrowband systems:
Digital Up Converters (DUC) and Digital Down Converters (DDC) are key components of RF systems in communications, sensing, and imaging. This application note demonstrates how efficient DUC/DDC implementations can be created by leveraging Xilinx® DSP tools and IP portfolio for increased productivity and reduced development time. While previous application notes have provided examples of DUC and DDC implementation in wideband
communications systems, this document concentrates on narrowband systems and the
building block components available to meet the particular requirements of such designs.
Step-by-step guidance is provided on how to perform simulation of narrowband DUC/DDC systems in MATLAB®, how to map functions onto building blocks and IP cores for Xilinx® FPGAs in System Generator software, and how to verify the implementation against the simulation model. Two examples are provided: a multi-carrier GSM system (both DUC and DDC) and a multi-channel MRI receiver (DDC only).
Teensy SDR transceiver description
rheslip has been working on a software defined radio using the Arduino compatible Teensy 3.1 and audio shield from PJRC.
Source code is available on Github.
Project info at Open Emitter blog.
Free PCB coupon via Facebook to 2 random commenters
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:
- Free PCB Sunday. The classic. Every week, get free PCBs right here on the blog comments
- Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
- Facebook PCB Friday. Free PCBs while you wait for the weekend
- Check out our video on how we mail PCBs worldwide.
Continue reading “Free PCB coupon via Facebook to 2 random commenters”
Mini stereo SE tube amp
Gert of KGELABS posted a step by step guide of his DIY small stereo amplifier:
This project started after getting an old schoolproject from a friend. A metal chassis with a single ECL86 tube, a power transformer and a small Muvolett (Amroh) 7044 output transformer. Intrigued by the simplicity of this amplifier I decided to rebuild the amplifier into a small stereo amplifier.
KF5OBS’ Dirty PCBs review
KF5OBS’ first PCB manufacturing run with Dirty PCBs:
So what’s the quality of the board? For $ 33 delivered I naturally didn’t expect much. But I was wrong. First off, I received 12 PCBs. So the Protopack definitely worked in my favor over ordering a guaranteed 10 pack for twice the price. Asides from some minor imperfections on the “J2″ outline, the silk-screen is of very good quality. Even the small text is clearly readable. I’ve often had issues with crappy silk-screen even with “high quality” services so this really impressed me. The vias also look very satisfactory.
Laser cut cases for Bus Pirate and Logic Pirate
Chase made custom 3D printed/laser-cut cases for the Bus Pirate and Logic Pirate. These cases are up on Thingiverse.
See other cases too.
Thanks Chase! Via the contact form.
Kit assembly 0-30V 0-3A adjustable linear power supply
Florin of YourITronics writes, “In this video I am assembling a 0-30V 0-3A Adjustable Linear Power Supply kit. Will it work at first power on? Or will Murphy get me this time? Watch the video and see how I got myself into trouble. I also reverse engineered and got a schematic of this kit which I am showing towards the end of the video.”
Yet another laser oscilloscope
Kerry Wong writes:
You can generate some pretty amazing patterns by shining a laser onto a mirror mounted on a vibrating speaker cone, a lot of people have experimented with this kind of laser show. But how about building a true laser oscilloscope that is capable of displaying signals? In this post, I will show you just that. For those who are impatient, I included a video towards the end.
Project info at Kerry Wong’s site.
Check out the video after the break.
Embrio tutorial – Custom Arduino nodes
A followup to the Embrio – a visual programming environment for Arduino post. Ezra Schwartz, maker of Embrio, just posted a new version of the software with better functionality for writing Arduino code right into a visual node:
Embrio lets you create the logic and structure of your programs with it’s powerful “agent based” architecture, but also lets you write code when needed. This tutorial shows how to interface with just about any hardware component by writing Arduino code directly into a Custom Arduino Node.
For more details visit Embrio tutorial here.
Via the comments.
STM32 ADC
Shawon Shahryiar over at Embedded Lab has written an article discussing the basics of STM32 ADC:
The block diagram shown above might look a bit complex at first but it still worth having a look. It shows us the interfaces that are related to the ADC block and some key features. It seems that some external interrupt pins and internal timer peripherals have some kind of relation with the ADC block. Well these hardware peripherals can trigger ADC conversion. The more we go forward, the more we explore. In short I would like to point out some key features of a typical STM32 ADC:
- 12-bit successive approximation ADC
- Maximum ADC conversion rate is 1MHz and more than 2MHz in some STM32 families
- A/D conversion range: 0 – 3.6V DC
- ADC power supply operating range: 2.4V – 3.6V DC
- ADC input range: (V_Ref- and V_Ref+ pins are available only in some devices and packages)
- Different modes of operation available for different measurement cases
- Dual mode conversion on devices with at least 2 ADC units. Some devices have more than 2 ADCs
- An integrated ADC sequencer ranks channels according to order
LaserOscope project
Steve Schuler over at Science2.0 published a new build: A laser oscilloscope using Lego, littleBits, Erector set, and the Kano Computer
Build a laser oscilloscope using Lego, littleBits, Erector set, and the Kano Computer. In honor of The International Year of Light I’ll demonstrate how use the Kano computer to drive a littleBits motor with an optical coupler, or optocoupler. An optocoupler, according to Wikipedia, “is a component that transfers electrical signals between two isolated circuits by using light.” The Kano Computer is one isolated circuit and the littleBits Light Sensor/Motor is the second isolated circuit. I’ll use the Kano Computer to flash an LED (Light Emitting Diode) and these flashes are read by the littleBits Light Sensor to turn the littleBits motor on and off.
Via the contact form.
Project info at Science2.0 site.
ESP-03 modules with the Bus Pirate
Tim Jagenberg writes:
Today I received the ESP-03 modules I had ordered from Shanghai. A nice little breakout for the ESP8266EX with ceramic antenna. Due to the 2mm spacing between the contacts on the sides, I had to bend the headers into shape before soldering them to the module.
As an initial function test I used the Bus Pirate in UART bridge mode to flash the latest NodeMCU firmware onto the chip.
Get an assembled Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.
DIY Internet connected smart humidifier
Martin’s DIY Internet connected smart humidifier project:
The project uses a DHT22 temperature sensor mounted to the side of the enclosure for better ventilation and reliable reading:
I threw in a ultra-cheap I2C OLED status display to get a visual reading. Milling the box so that the OLED shows was pretty nasty, hated it. I cut a piece of paper and placed it on top of the cover, below the transparent lid to cover up for the lousy milling job
The humidistat switches on and off the humidifier as needed, the humidifier itself is plugged in to a plug in the relay. The humidifier auto detects when water is out and stops, so I didn’t have to care about that.
Source code for the project is available on GitHub.
Project info at Martin Harizanov’s site.