Getting an Arduino to control a wireless outlet

arduino-433-mhz-outlet-control

[Reza's] methodical investigation of this remote controlled outlet let him patch in with an Arduino using a 433 MHz transmitter. This is a single-device unit, but the techniques used here should allow you to take control of wireless rigs that have multiple modules to control many devices.

We’ve seen some folks at our local hackerspace try to patch into the remote control itself. That used some type of weird button scanning (not just connecting a pin to ground or voltage) and didn’t pan out. [Reza] doesn’t even crack open the case of either of the units seen above. Instead, he goes straight for a wireless receiver he had on hand, using a logic analyzer to capture the signals coming from the remote.

Once he had a good snapshot of the signals sent when pressing the on or off button of the remote he set out to replicate it in his Arduino code. His function called setStateWithDelay takes three parameters: the transmit pin, the level (high or low), and a number of milliseconds to delay. Each signal calls this function many times, but working the bugs out is pretty easy; just capture the signal with the logic sniffer and compare to the stock remote.

Turning the Stellaris Launchpad into a logic analyzer

acquisition

If you have a Stellaris Launchpad sitting around, have a go at using it as a logic analyzer

The Stellaris logic analyzer is based upon this earlier build that took code from a SUMP comparable Arduino logic analyzer and ported it to the much faster and more capable Stellaris Launchpad with an ARM Cortex 4F processor.

This build turns the Launchpad into a 10 MHz, 8-channel logic analyzer with a 16 kB  buffer comparable with just about every piece of software thanks to the SUMP protocol. Even though the ARM chip in the Launchpad isn’t 5 Volt tolerant, only pins 0 and 1 on Port B are limited to 3.6 Volts. All the other pins on Port B are 5 Volt tolerant.

Not a bad piece of work to turn a Launchpad that has been sitting on your workbench into a useful tool.

Tiny OLED oscilloscope gets a fancy case

[Gabriel Anzziani] has just unleashed a newer, more convenient version of his Xprotolab portable oscilloscope, logic analyzer, and function generator. It’s up on Kickstarter, and the price is actually very nice for a tool of this caliber.

We first saw the Xprotolab early last year and ran into [Gabriel] at this year’s World Maker Faire in New York. On both occasions we were impressed with the size and capability of this very, very small OLED-display oscilloscope and general breadboarding Swiss army knife.

The Xprotolab features a two-channel, 200 kHz oscilloscope, 8-input logic analyzer, and an arbitrary waveform generator that should be good enough for all your breadboarding adventures. On top of that, the Xprotolab can sniff SPI, I2C, and UART protocols, and even has a small spectrum analyzer tucked away in a device small enough to lose in your pocket.

The updated-for-Kickstarter Xprotolab features an enclosure with a LiPo battery good for 12 hours of use per charge. Sure, it’s not a bench full of old HP and Tektronix gear, but for the budding maker, this seems like a very useful tool indeed.

Tiny OLED o-scope fits on a breadboard

With a surplus of 3D printers at this year’s Maker Faire, it’s really surprising to see the most talked about tool among the makers is a simple oscilloscope.

[Gabriel Anzziani]‘s Xprotolab is an extremely small oscilloscope, function generator, logic analyzer, and general 128×64 OLED display is the perfect addition to your next prototyping project. With its breadboard friendly format and USB output, it will dutifully serve as a 200kbps oscilloscope, 8 channel logic analyzer, or as seen in the video above, the perfect interface for a Wii Nunchuck or just a simple digital Etch-a-sketch.

In the video above the fold [Gabriel] shows off the functions of his tiny, if somewhat limited, OLED oscilloscope.

Logic analyzer add-on for the MSP430 Launchpad

Here’s a 6-channel logic analyzer shield for the MSP430 Launchpad. It manages an eyebrow-raising 16 million samples per second. The prototype seen above is made on a hunk of protoboard with point-to-point soldering. [oPossum] did lay out a PCB — which is just 50mmx50mm — but has not had any produced quite yet.

He calls it the LogicBoost, and based it on the the LogicShrimp design. The sextuplet of 8-pin chips are all SPI RAM. These are responsible for storing the samples, with a 74HC573 latch routing the traffic. The MSP430 chip provides the SPI clock, and the Launchpad’s virtual com port can be used to push the data to a computer for graphing. That’s a bit slow so [oPossum] also included an optional header for an FTDI board that will do a faster job. The sample rate can be adjusted by tweaking the internal oscillator setting of the chip; there’s plenty to choose from so it will work for just about any purpose (as long as you don’t surpass the 16 Msps speed limit).

[via Dangerous Prototypes]

Turning an oscilloscope into a logic analyzer

Sooner or later, you’re going to need a logic analyzer. If you don’t have a Bus Pirate or Logic Sniffer lying around, [Joonas] has a great MacGyverism that turns an oscilloscope into the simplest logic analyzer ever.

The basic premise of the build is tying four digital lines to the analog input of an oscope. This is done with a 74HC126 buffer that provides a high impedance input for the logic probes and outputs the four-bit status of each logic channel. With a few resistors in an R-2R network, the state of four digital lines can be easily read.

[Joonas] included the source code to turn his Picoscope 2000 into a logic analyzer, but there’s no reason why this couldn’t be done with any digital scope that has a serial output. Not bad for a very, very simple logic analyzer – just one chip and a handful of resistors – that costs less than $5.

Using the parallel port as a logic sniffer

[Fernando] wrote in to share his take on building a logic analyzer. He’s using the parallel port to capture data and feed it to the display software of your choice.

The method depends on a custom kernel which alters the way the parallel port works. The kernel he compiled includes a method of intercepting the signals coming in from the hardware, passing that data to the /dev/parport* as it should, but also sending a copy to /dev/parportsnif*. It also creates a log file which is in the OpenBench Logic Sniffer format for easy use with various display software.

Of course this is easiest to use with a Linux system, but can also be run as a virtual machine under Windows. We’d plan on using a virtual machine within Linux as well since this is a custom kernel and will probably only see occasional use.