Raspberry Pi

1836 Articles

Feed That Shoulder Boom Box With A Wrist Tune Transmitter

October 5, 2014 by 13 Comments

Next time you’re strutting down the block with that hi-fi on you shoulder, don’t subject yourself to the limitations of a radio station’s tight playlist or the short run time of a cassette tape. Pack your tunes on your wrist and beam them directly with this wearable FM transmitter. No wires… it’s like the future is now!

The Raspberry Pi has proven itself to be a dependable FM transmitter. This project follows in those footsteps but moves the goal line a few leaps further. The build has a full user interface which will make it easy to adapt to just about any application you can imagine. And the added twist is shown in the latter third of the video after the break. [Navic209] has included a microphone in the design which allows the wearer to transmit voice to an appropriately tuned radio. It gives the device a very Dick Tracey-esque feel.

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supercapacitor ups

Supercapacitors For The Raspberry Pi

October 4, 2014 by 45 Comments

As versatile as the Raspberry Pi is, it has a weakness when it needs to be able to shut down properly during a power outage, especially when handling data-sensitive or industrial applications. To solve this problem, [Pavol Sedlacek] has created a supercapacitor-based UPS specifically for the Raspberry Pi that gives it enough time to properly halt its processes and shut down if it detects a power failure.

The device is called the Juice4Halt. It uses a DC-DC converter to provide power to the Pi from the normal power supply and to charge the supercapacitors during normal operation. It is bidirectional, so in the event of a power failure it works in reverse to take power from the capacitors and feed it back to the Pi. A second DC-DC converter handles power from an external power supply.

A side effect of using supercapacitors as a UPS is that they can also help the Pi survive brownouts. The project site has an incredible amount of detail about the functionality of the device, including circuit diagrams and the source code. We’ve seen other supercapacitor-based UPS units before but this particular one is much more robust and would be truly at home in any industrial or other sensitive setting.

Raspberry Pi IR camera

Camera Mod Lets This Raspberry Pi Shoot In Different Spectrums

October 3, 2014 by 7 Comments

For [Peter Le Roux’] first “real” electronics project, he decided to make a camera based off the venerable Raspberry Pi platform. But he didn’t just want a regular camera, he wanted something that could shoot in near IR wave lengths…

It’s a well-known fact that you can remove the IR blocking filter from most cameras to create a quasi IR camera hack – heck, that hack has been around nearly as long as we have! The problem is even if you let the IR light into the camera’s sensor, you still get all the other light unless you have some kind of filter. There are different ways of doing this, so [Peter] decided to do them all with an adjustable wheel to flip through all the different filters.

He designed the case after the PiBow enclosure – you can see our full Pi Case Roundup here – and had it all laser cut out of wood. Stick around after the break to see a nice explanation of the light spectrum and the various filters [Peter] uses.

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Sweet Stepper Of [Jeremy]’s Rocks Out With Its Box Out

September 18, 2014 by 12 Comments

Inspired by the floppy drive orchestras of others, [Jeremy] has built a Pi-driven MIDI music box with stepper motor resonators and outlined the build on hackaday.io.

Control for the motors comes from an Iteaduino Mega 2560. The music starts as a MIDI file, gets processed into a text file, and is played over serial by a Raspberry Pi. He’s added percussion using K’NEX instruments and 9g servos, which we think is a nice touch. It can be powered via LiPo or from the wall, and [Jeremy] baked in protection against blowing up the battery. As he explains in the tour video after the break, the box is clamped to a wooden table to provide richer sound.

[Jeremy]’s favorite part of the build was enclosing the thing as it was his first time using panel-mount components. Stick around to see a walk-through of the guts and a second video demonstrating its musical prowess.

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Subway radar

LEDs Turn This Paper Map Into A Tram Tracker

September 15, 2014 by 14 Comments

Public transit can be a wonderful thing. It can also be annoying if the trains are running behind schedule. These days, many public transit systems are connected to the Internet. This means you can check if your train will be on time at any moment using a computer or smart phone. [Christoph] wanted to take this concept one step further for the Devlol hackerspace is Linz, Austria, so he built himself an electronic tracking system (Google translate).

[Christoph] started with a printed paper map of the train system. This was placed inside what began as an ordinary picture frame. Then, [Christoph] strung together a series of BulletPixel2 LEDs in parallel. The BulletPixel2 LEDs are 8mm tri-color LEDs that also contain a small controller chip. This allows them to be controlled serially using just one wire. It’s similar to having an RGB LED strip, minus the actual strip. [Christoph] used 50 LEDs when all was said and done. The LEDs were mounted into the photo frame along the three main train lines; red, green, and blue. The color of the LED obviously corresponds to the color of the train line.

The train location data is pulled from the Internet using a Raspberry Pi. The information must be pulled constantly in order to keep the map accurate and up to date. The Raspberry Pi then communicates with an Arduino Uno, which is used to actually control the string of LEDs. The electronics can all be hidden behind the photo frame, out of sight. The final product is a slick “radar” for the local train system.

Raspberry Pi Gets VGA, Dual Screen Support

September 10, 2014 by 47 Comments

The Broadcom SOC in the Raspberry Pi is actually surprisingly powerful, it turns out. It’s actually capable of driving a VGA monitor through the GPIO pins using a handful of resistors.

[Gert van Loo], Raspberry Pi chip architect, wizard, and creator of a number of interesting expansion boards showed off a VGA adapter for the new B+ model at the recent Raspberry Pi Jam in Cambridge this week. Apparently, there is a parallel interface on the SoC that can be used to drive VGA with hardware using a resistor ladder DAC. That’s native VGA at 1080p at 60 fps in addition to HDMI for the Raspberry Pi. Only the new Model B+ has enough pins to do this, but it’s an intriguing little board.

The prospect of having two displays for a Raspberry Pi is very interesting, and the remaining four GPIOs available mean a touch screen could be added to one display, effectively making a gigantic Nintendo DS. Of course there are more practical problems a dual display Raspi solves, like driving a projector for the current crop of DSP/resin 3D printers, while still allowing for a usable interface during a print.

The VGA expansion board, “is likely to have issues with EMC,” which means this probably won’t be a product. Getting a PCB made and soldering SMD resistors isn’t that hard, though, and we’ll post an update when the board files are released.

Thanks [Uhrheber] for sending this one in.

Hackerspace Monitor

HackerSpace Monitor Monitors Hackerspace Environment

September 9, 2014 by 1 Comment

What’s going on at the Hackerspace? If you can’t answer that, maybe your ‘space needs a HackerSpace Monitor. [Tayken] over at the Tokyo Hackerspace has come up with a way to remotely monitor all the stuff you’d want to know about the ‘space.

His project is based on a Raspberry Pi with a webcam connected to the Pi’s USB port by way of a hub. The webcam is set up to stream 2 frames per second, which is plenty to be able to judge the activity at the ‘space. A WiFi dongle is also plugged into the USB hub in order to gain internet access, send out the video and allow the ability to SSH into the Pi.

What if you’re on the fence about heading over to work on your favorite project but the current weather leaves you wondering what the temperature is going to be like at the hackerspace? Well, this project has that covered too. An off the shelf temperature and humidity sensor plugs directly into the Pi’s GPIO pins. [Tayken] used the Python-based package, RPi.GPIO, to manage the temperature and humidity sensor readings as well as a toggle switch that monitors if the main door is open or closed.

To get everything all the above information to be displayed on a webpage, [Tayken] had to do some fancy programming. Luckily for us, he has made all his code available for download. Not only is this a great convenience for members, but it can also show non-members when it is or isn’t a good time to show up to check the ‘space out.