Hack Mobile with a Bus Pirate GUI for Your Phone

You need to get an SPI bus on something right now, but you left your laptop at home. No problems, because you’ve got your Bus Pirate and cellphone in your pocket. And a USB OTG cable, because you’re going to need one of those. And some probes. And maybe a soldering iron for tacking magnet wire onto those really small traces. And maybe a good magnifying glass. And…

OK, our fantasy of stepping away from the party for a quick JTAG debugging session is absurd, but what’s not at all absurd is the idea of driving your Bus Pirate from a nice GUI app on your Android phone. [James Newton] wrote DroidScriptBusPirate so that he wouldn’t have to hassle with the Bus Pirate’s nested single-character menu system, and could easily save complete scripts to do common jobs from pleasant menus on his phone.

The setup depends on downloading DroidScript, a free Javascript and HTML5 IDE, and then pasting and saving [James]’ code. He’s written up full instructions to help you with the install. It’s not so hard, and once you’re done you’ll be ready to drive the Pirate from the comfort of your phone.

In fact, now that we think of it, we’re missing a Bus Pirate GUI for our desktop as well. Whenever we have complex tasks, we end up scripting something in Python, but there ought to be something more user-friendly. Anyone know of a good GUI solution?

A Power Switch for the Chromecast

Chromecasts are fantastic little products, they’re basically little HDMI sticks you can plug into any monitor or TV, and then stream content using your phone or computer as the controller. They are powered by a micro USB port in the back, and if you’re lucky, your TV has a port you can suck the juice off. But what if you want to turn it off while you use a different input on your TV so that your monitor will auto-sleep? You might have to build a power switch.

Now in all honesty, the Chromecast gets hot but the amount of power it draws when not in use is still pretty negligible compared to the draw of your TV. Every watt counts, and [Ilias] took this as an opportunity to refine his skills and combine a system using an Arduino, Bluetooth, and Android to create a robust power switch solution for the Chromecast.

The setup is rather simple. An HC-05 Bluetooth module is connected to an Attiny85, with some transistors to control a 5V power output. The Arduino takes care of a bluetooth connection and uses a serial input to control the transistor output. Finally, this is all controlled by a Tasker plugin on the Android phone, which sends serial messages via Bluetooth.

All the information you’ll need to make one yourself is available at [Ilias’] GitHub repository. For more information on the Chromecast, why not check out our review from almost three years ago — it’s getting old!

Android Set Top Box Lets You Stream and Record via HDMI Input

While on the hunt for some hardware that would let him stream video throughout his LAN [danman] got a tip to try the €69 Tronsmart Pavo M9 (which he points out is a re-branded Zidoo X9). With some handy Linux terminal work and a few key pieces of software [danman] was able to get this going.

The Android box was able to record video from the HDMI input with pre-installed software found in the main menu as [danman] explains on his blog. File format options are available in the record menu, however none of them were suitable for streaming the video (which was the goal, remember?).

[danman] was able to poke around the system easily since these boxes come factory rooted (or at least the Tronsmart variant that [danman] uses in his demo did). Can anyone with a Zidoo X9 verify access to the root directory?

Long story short, [danman] was able to get the stream working over the network. Although he did have to make some changes to the stream command he was issuing over ssh. He finds the fix in the ffmpeg documentation which saves you the trouble of reading through it but you’ll have to check out his blog post for that (pro tip: he links to a sweet little .apk reverse engineering tool as well).

We’ve seen set top box hacks before, however, streaming and recording HDMI at this price is a rare find. If you’ve been hacking up the same tree let us know in the comments, and don’t forget to send in those tips!

Radio Receiver Build Log and More

At Hackaday, we like to see build logs, and over on Hackaday.io, you can find plenty of them. Sometimes, though, a builder really outdoes themselves with a lot of great detail on a project, and [N6QW’s] Simple-Ceiver project certainly falls into that category. The project logs document many different stages of completeness, and we linked the first one for you as a starting point, but you’ll definitely want to read up to the present. (There were 16 parts, some spanning multiple posts, last time we checked).

It is definitely worth the effort though. The project started out as a direct conversion receiver, but the design goes through and converts it into a superheterodyne receiver. Along the way, [N6QW] shares construction techniques, design advice, and even simulation plots (backed up with actual scope measurements). The local oscillator, of course, uses an Arduino and an AD9850 synthesizer.

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Start Gaming Early with IKEA High (Score) Chair

If you want your kid to be really great at something, you have to start them out early. [Phil Tucker] must want his kid to be a video gamer pretty badly. [Phil’s] build starts with a $20 IKEA high chair. He likes these chairs because at that price point, tearing into them isn’t a big risk. What’s more is you can buy extra trays so you can use it as a modular project with different trays serving different purposes.

The chair has two joysticks and two buttons, looking suspiciously like a video game controller. The current incarnation (see video, below) uses an Arduino Uno to trigger an Akai MPC1000 synthesizer via the MIDI interface.

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Object Oriented State Machine Operating System Goes Open Source

On a desktop computer, you think of an operating system as a big piece of complex software. For small systems (like an Arduino) you might want something a lot simpler. Object Oriented State Machine Operating System (OOSMOS) is a single-file and highly portable operating system, and it recently went open source.

OOSMOS has a unique approach because it is threadless, which makes it easy to use in memory constrained systems because there is no stack required for threads that don’t exist. The unit of execution is a C++ object (although you can use C) that contains a state machine.

You can read the API documentation online. Just remember that this is not an end user OS like Windows or Linux, but an operating environment for managing multiple tasks. You can, though, use OOSMOS under Windows or Linux as well as many other host systems.

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Your First GNU Radio Receiver with SDRPlay

Although GRC (the GNU Radio Companion) uses the word radio, it is really a graphical tool for building DSP applications. In the last post, I showed you how you could experiment with it just by using a sound card (or even less). However, who can resist the lure of building an actual radio by dragging blocks around on a computer screen?

For this post and the accompanying video, I used an SDRPlay. This little black box has an antenna jack on one end and a USB port on the other. You can ask it to give you data about a certain area of the RF spectrum and it will send complex (IQ) data out in a form that GRC (or other DSP tools) can process.

The SDRPlay is a great deal (about $150) but if you don’t want to invest in one there are other options. Some are about the same price (like the HackRF or AirSpy) and have different features. However, you can also use cheap TV dongles, with some limitations. The repurposed dongles are not as sensitive and won’t work at lower frequencies without some external help. On the other hand, they are dirt cheap, so you can overlook a few little wrinkles. You just can’t expect the performance you’ll get out of a more expensive SDR box. Some people add amplifiers and converters to overcome these problems, but at some point it would be more cost effective to just spring for a more expensive converter.

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