Tag Archives: Raspberry Pi Accessories

Graspinghand’s SweetBox, ScorPi and Heatsinks for the Raspberry Pi

Those who need a casing for their Raspberry Pi or RBPi are rather spoiled for choice. There are so many types of casings available, and that makes it so difficult to settle on one. Sometimes, you need a casing that does not take up too much space, but is able to protect your RBPi from sundry damage. If you want the smallest case on the market, try the SweetBox from Graspinghand.

Besides being the smallest on the market, SweetBox is injection molded with high-performance nylon, and is compatible with RBPi models B, Rev 1 & 2. It has several features such as it allows the insertion of a Micro-SD card into its adapter and the mounting of the RBPi camera. A rubber cap protects the GPIO pins when not in use, and is easily removable to allow connections.

Slots on the casing allow easy access to the DSI or Digital Serial Interface for attaching an LCD panel to the RBPi and the CSI or Camera Serial Interface for attaching a camera. Other mounting holes are available on the base, while the entire casing allows simple opening and closing without any screws or tools.

SweetBox is made from high-performance nylon, the EMS Grilamid type typically used for glass frames, electrical equipment and tools. This material makes the casing nearly unbreakable. The material is also lightweight, and the casing is only 35gms with dimensions of 95x65x25mm.

However, one of the most remarkable features of the SweetBox is it allows heatsinks to be mounted, so that your RBPi can operate within the casing, but without getting all heated up. Graspinghand offers three CNC machined heatsinks that you could use with or without SweetBox. The three heatsinks come with ready-to-mount thermal pads. With the heatsinks fitted, your RBPi will run at least 4°C cooler at full power.

Placing the heatsinks requires some dexterity. First, you must peel off the protective film off one side of a thermal pad. Then fix the heat sink very carefully in the center of the uncovered surface – this will stick the thermal pad to the heatsink. If there is excess thermal pad protruding out around the heatsink, use scissors to cut it off. Now peel off the remaining protecting film from the other side of the pad and place the heat sink and pad combination very carefully on top of the IC to be cooled. Use the same procedure for mounting all the three heatsinks, taking care to keep the same orientation of the fins for all the three.

Graspinghand also offers ScorPi, a flexible gooseneck arrangement for holding things such as the camera board on the RBPi. A brass fixture allows the ScorPi to be attached to SweetBox, while the brass fixture on the other end of ScorPi attaches to the camera board. You can flex the ScorPi to position the camera at any angle required, and it will remain in position to allow capturing images without any blurring due to shaking.

Cleaning the ScorPi is also very easy, as you can loosen all parts and clean them with a soft wipe using a mixture of white vinegar and salt.

Make the OpenJFX DukePad with a Raspberry Pi

If you are looking for a fun project aimed at making your own tablet computer at home based on the Raspberry Pi (RBPi) Single Board Computer, the DukePad is for you. As software, you will use the Raspbian Linux operating system and your environment will be OSGi-based JavaFX.

You can think of DukePad not as a product but an open-source set of plans and software freely available for assembling your own tablet for which, you will be using off-the-shelf components. At present, the DukePad software environment is only demo-quality, as more importance has been given to making the software for demonstration purpose rather than for real functionality.

Although, for the purpose of this guide, you need to name your RBPi with the host name of “dukepad”, you could have any other name of your choice. In addition, instead of letting the RBPi run X11, which it is fully capable of running, JavaFX will be used and it will take over the entire screen. However, while downloading the software into your RBPi, you may choose either to start up with X, or you could elect to download to your desktop PC and then scp/sftp the files into your RBPi.

To get started, you must set up your RBPi as usual; follow these steps if you do not know how. Setup you RBPi such that you have allotted a generous amount of memory to VRAM, also called graphic memory or Video Core. An even split of 256MB each for VRAM and for system memory is also acceptable. If you only have 256MB in total, you may also get by with a 128MB/128MB split, but you may have to tweak the amount of VRAM that FX will eventually use.

If you have not already downloaded and installed the latest JavaSE Embedded release, you may do so now. You can use either the weekly builds or the official builds, whichever is available. For the RBPi, you will have to look for Linux ARMv6/7 VFP, HardFP ABI. Other versions are not likely to work with RBPi.

For installation, you must uncompress the file you have downloaded and put it in a directory of your choice. A good choice would be to install it in the directory /opt; this will require you to assume the superuser status (root). Once you install JavaSE Embedded, it will include JavaFX as well. To play media, RBPi will need some additional packages. You will also need additional packages for configuring the auto-booting and the splash screen. In case you are not interested in creating a table device and you are simply planning to play with the DukePad software, you may safely skip the splash screen and auto boot instructions.

For the boot-loading screen, you need the “fbi” package and for being able to play media files, you have to download and install the “mpg321” package.

For building the body of DukePad, the CAD files are provided here. They contain the template for laser cutting the acrylics for the body, which is made from material of two thicknesses – 4.5mm and 3mm.

Raspberry Pi Gesture Control

Many smartphones are capable of gesture control, where the phone can sense movement of the owner’s hands near it and respond accordingly. Now you can add the same features to the versatile credit card sized single board computer, the Raspberry Pi or RBPi. The features are provided by the Microchip 3D Gesture Controller, the MGC3130 GestIC and a 3D Touchpad.

The hardware you will need for implementing the gesture control is the MGC3130 Hillstar Development Kit, a 5V, 1.2A power supply with a microUSB connector and an RBPi Model B, preferably V2. Initially, you will need access to a PC for parameterization and for flashing the firmware on the MGC3130. After the flashing is over, the MGC3130 can communicate directly with the RBPi via the GesturePort available of the tiny MGC3130 board on the Hillstar dev kit. The Hillstar board needs signals EIO1, EIO2, EIO3, EIO6 and EIO7, which the RBPi supplies via its GPIO connector.

3D gesture sensing and control applications require capacitive sensing, which the MGC3130 handles aptly. You can either power the Hillstar board from the USB charger, or let the RBPi power it up directly. Once connected, the MGC3130 senses the North-South and East-West hand flicks. The EIOx pins flag the gestures sensed to the RBPi, which then acts on them according to actions already assigned.

The GestIC controller has Aurea, a free graphic shell working around it. Aurea allows parameterization of several planes of different sizes and configuration. These planes make up the capacitive sensing pad and you can calibrate and configure them with good precision. For programming, you will require the Raspbian OS Debian Wheezy – version January 2014, Python – version 2.7.3, RPI.GPIO – version 0.5.4, Tkinter and Leafpad. All the above software are already included in the Raspbian OS. To demonstrate the functioning of the gesture controller, you can use the python code for the game “2048” – 2048_with_Gesture_Port_Demo.py.

The software package for the MGC3130 contains all the relevant system software and its documentation. The package, provided by Microchip, contains the PC software Aurea, the GestIC Library binary file, the GestIC Parameterization files, CDC driver for Windows and the relevant documentation. You can use the Software Development Kit, also from Microchip, for integrating the MGC3130 into a software environment, as it includes a C-reference code for the GestIC API, a precompiled library for the Windows operating system. It also includes a demo application (the game “2048”) that uses the GestIC API interface on the Hillside Development Kit.

The Hillstar Development Kit provides a reference electrode of 95×60 cm for the touchpad. This consists of one Transmit and a set of five Receive electrodes – one each for north, east, south, west and center positions. These electrodes are placed in two different layers. To shield the Transmit electrode from external influences, it has a ground layer just underneath.

The five Receive electrodes include the four frame electrodes and one center electrode. The frame electrode names follow from their cardinal directions, that is, north, east, south and west. The maximum sensing area is defined by the dimensions of the four Receive frame electrodes. The center electrode is positioned to get a similar input signal level as received by the four frame electrodes.

Raspberry Pi accessories from Microstack

If you are looking for accessories for your tiny, credit card sized single board computer, the Raspberry Pi or RBPi, you now have a series of them from the distributer element14. This Microstack range of accessories allows all levels of users to create and prototype physical devices simply and quickly. Most popular among the Microstack accessories are the GPS positioning and accelerometer.

Microstack claims that its modules are the “building blocks for the Internet of Things for All”. The original designers of PiFace Digital and PiFace Control and Display accessories for the RBPi have come together to create Microstack. In fact, building on PiFace, Microstack now offers several types of connected-device possibilities for the RBPi.

Microstack offers a family of stacking accessory boards that a compact and reusable. They offer a common form factor, interface connections and software. All the accessories for the RBPi are built on a platform-specific baseboard called the adapter board.

The GPS module from Microstack is a simple and easy plug-and-play solution. You can use this module for projects requiring GPS positioning for creating geo-location awareness. The GPS module has several worthwhile features. Not only can the module log data in its standalone mode, it allows the RBPi to keep time in a highly accurate and globally synchronized manner. The Microstack GPS module is one of the most complete and advanced modules and it sports an embedded high sensitivity 15×15 mm internal patch antenna with an external socket.

The antenna switching function is automatic as the GPS module has antenna detection feature along with short circuit protection. For better sensitivity, the module has a built-in LNA. The advanced AGPS technology works with an intelligent controller of periodic mode that does not require any external memory. Microstack has provided LOCUS as an innate logger solution that works independently without host and external flash. The GPS module comes with anti-jamming features that sports Multi-tone Active Interference Canceller with 66 acquisition channels and 22 tracking channels. You can combine it with other Microstack add-ons to provide radio links for supporting remote telemetry.

The Accelerometer module from Microstack is also a simple plug-and-play device for the RBPi. It is useful where measuring acceleration is necessary for projects such as tracking and motion, game and tilt sensors and robotics. The module is based on MMA84910, a simple, low power, three-axis low-g accelerometer that offers multi-range 14-bit at +/- 8g resolution.

With a 1.95-3.6 V supply voltage range, the Accelerometer module consumes only 400 nA per Hz, but provides data at ultra-high speeds in about 700µS. Its 14-bit digital output has a sensitivity of 1 mg/LSB with a +/- 8g full-scale range. The Microstack framework compatible accelerometer module has 45° tilt outputs for its three axes and you can link it to your RBPi with the I2C interface.

You can use the Microstack modules as standalone or integrate them into full custom PCBs. Therefore, the modules provide a solution right from prototyping to production. These modules offer powerful building blocks that cut down on the development time with support software and easy installation.

Raspberry Pi add ons

Accessories have been flooding the market ever since the release of the tiny Single Board Computer Raspberry Pi (RBPi). Some of them merit a closer look because they can take your RBPi to the next level.

MotorPiTX board

For people interested in projects that need to run motors such as in robotics, the MotorPiTX board is a great accessory. It fits on top of the SBC and comes packed with some interesting features such as its own power supply (four AA batteries). This is enough to run the RBPi along with attached motors and servos. Full ATX style power controls are available, such as two 5V outputs (for LEDs), two bi-directional DC motor connectors, two servo connectors, two 3.3V inputs, one I2C breakout board and a micro-USB port.

A Smart IO Expansion Card

You can stack this add-on device atop the RBPi. As this is a super IO port, you can connect just about anything to it. There are 13 inputs for analog, pulse and digital signals, two analog outputs, eight digital outputs capable of 1A and ports for AHRS, CAN, RS485 and RS232. Apart from using it as an electronic test platform, the card can also be used for home automation, machine control, UAVs and robotics navigation.

The Pi Crust

This breakout board sits on top of the RBPi like a crust, allowing users to connect a multitude of devices easily. Rising only a scant 2mm above the RBPi base, the crust does not interfere with any other device connected to the RBPi. Pins are clearly labeled together, grouped logically together and include power, UART, SPI, I2C and GPIO. Female headers allow ease of connection along with plenty of GND and 5V pins.

SweetBox, Heat Sinks and ScorPi

SweetBox is a minimalistic approach to an enclosure for the RBPi and the smallest one in the market. It comes with a removable, flexible GPIO cap, allowing access to plug-in components. The SweetBox also has a set of anodized aluminum heat sinks that aid in extra heat dissipation. ScorPi is a flexible mount allowing the user to mount an RBPi camera, with direct plugin into the RBPi’s RCA port.

Power Supply Ignition Switch

This attachment allows using the RBPi with vehicles. It allows powering the RBPi through the electrical system of the vehicle. As you engage the vehicle’s ignition or turn it off, the attachment senses and powers the RBPi on or off safely. The built-in converter takes in 12/14V from the vehicle and provides 5V to the RBPi. Its ignition sensing talks to the SBC through two of its GPIO pins. The attachment retains power for the RBPi for 20 minutes after switch off. That means frequent stops will not repeatedly boot your RBPi. Additionally, if you left the RBPi running in the vehicle, the automatic shutdown feature will shut it off after four-hours to no-user activity.

HDMIPi HD Screen Prototypes

These are 1290×800 displays, which are not too expensive, portable and only 9-inch in size. You can watch movies comfortably, or incorporate into whatever project that needs a display. The cost-to-size ratio is perfect, competing successfully with the other portable screens in the market.

An Exquisite Raspberry Pi Enclosure

There are countless types of enclosures available for the inexpensive credit card sized Single Board Computer – the Raspberry Pi, popularly known as the RBPi. All have their unique capabilities and advantages. Some are made of wood, some of paper while most others are made of plastic.

The molded enclosure from Hammond Electronics is specifically designed to house the RBPi model B. The exquisitely molded container is shaped like a book and is available in black, grey and translucent blue. The stylishly rounded design has apertures for all the IO interfaces and accessories supported by the RBPi. The enclosure is actually two parts made to fit one on top of the other, holding the RBPi between them. No screw-fixings are involved, and a specific sequence is required to get the bottom, the RBPi and the top fitted together perfectly.

On opening the 1593HAMPI enclosure assembly, you will notice the bottom half has some stationary clips on its inside. Holding the bottom half in your palm, slide the RBPi board in at an angle against these stationary clips. Once in place, push down firmly on the RCA jack of the RBPi, until you hear the board click into position. Now the RBPI is securely held in the bottom part of the enclosure.

Take the top part of the enclosure and touch its rounded ends to the corresponding rounded ends of the bottom part, on an angle. Still holding the bottom part firmly, push down on the outer edge of the top part, until you hear a snapping sound. On turning the assembly around, you will see a clip from the top part jutting through an opening on the bottom part. This holds both the halves together. In case you would like to separate the two parts of the enclosure, simply pull back the clip from the bottom part and the two halves will come apart.

Hammond Electronics offers self-adhesive rubber feet, which you can fit in the circles on the bottom part of the enclosure. They will prevent the encased RBPi from sliding off. One of the most popular accessories of the RBPi is the camera module. You have a choice of two methods for mounting the camera module. Screw the camera to the inside of the top part, which has a hole provided for the lens. However, if the camera must remain outside the enclosure, you can fit it through a slot in the top. The camera will now be standing at right angles to the assembly.

Access to the GPIO header is provided through a cutout on the mating line between the top and the bottom halves. The sides also have apertures of the right size and shape for all the ports. Therefore, you can easily access the HDMI interface, the micro-USB power-in connector, the RCA ports for audio and video, the SD card, the RJ45 LAN and the two USB ports. The base has two captive slots so that you can attach the enclosure to a surface. For stand-alone applications, the rubber feet are helpful.

Talk To Your Raspberry Pi through an FTDI Breakout Board

You do not really need a monitor and a keyboard for logging into the tiny credit card sized single board computer, the famous Raspberry Pi or RBPi; there are several ways to do that. One of the very simple ways is to listen in on two of the serial communication monitoring pins on the GPIO header of the RBPi.

Manufacturers of most computers have now given up on including serial ports on their products in favor of the more Universal Serial Bus or USB. However, connecting the serial pins on the RBPi to the USB port on the computer is not so straightforward. A special translator is required, one that understands and converts between the serial and USB protocols.

FTDI makes a special cable with an FT232 chip in between that can help to connect the serial port pins on the RBPi to the USB port of the computer and provide meaningful communication between the two. Modern Devices have gone one step further. Instead of having to deal with connectors or soldering on the RBPi side, they have designed a breakout board with the FT232 on it. The FT232 TTL signals are available on a header, which is suitable for plugging into the GPIO header on the RBPi; this is the USB BUB 1,

On one side of the BUB is an FTDI header, a six-pin version very common with most of the Arduino-compatible boards. The breakout area of the BUB is very handy as it allows you to reconfigure the signals to any of the pins on the second header. When you have to connect different devices such as the Parallax Propeller, this rerouting is very useful, as pinouts or the RBPi and the Parallax Propeller are different. The rerouting process also allows you to select the proper logic level (5V or 3.3V) for your device with a single jumper. You can suitably modify the breakout area of the BUB to enable it to connect appropriately to two different style devices without resoldering the connections.

When connecting to the RBPi, make sure you are connecting the Transmit of the RBPi to the Receive pin of the BUB, and the Transmit of the BUB to the Receive of the RBPi. Unless you follow this method of connections, BUB and RBPi will be unable to communicate with each other. For connecting with the RBPi, another very important thing to take care on the BUB is the logic level jumper. Make sure and double-check that it is connected to the 3.3V rail and NOT to the 5V.

Now that you have everything under control, boot up your RBPi, plug in the BUB and connect the other end of the serial cable to the USB port on your computer. All FTDI chips have a unique ID and this will show up as the device name. The device will be available under the /dev directory if you are using a Mac or Linux computer. On Linux, the BUB will show up as /dev/ttyUSBx, where x will depend on the number of USB devices already plugged in.

How to Paint with Light and Raspberry Pi

You can paint with light if you use a camera with large exposure times, while generating moving images with a Raspberry Pi (RBPi). Light painting is not new and traditionally images were hand-painted with a penlight. With the availability of cheap micro-controllers and addressable RGB LEDs, the idea of light painting has taken on a different meaning.

Since the images are large, producing them requires huge amounts of memory, something that RBPi has ample quantities of. Adafruit has Digital Addressable RGB LED Strips and connecting them to the Raspberry Pi is quite simple except that Raspberry Pi will not be able to supply the high currents that the LED strips demand, therefore, an external power supply will be required to power the strips.

Since the project will move about a lot, strong and reliable connectors will be required to interface between the Raspberry Pi and the LED strips. Connections from the GPIO of the RBPi are best taken via a 26-pin IDC cable and header. The LED strips are connected using two JST 4-pin plug and receptacle cables. The wires of the cables are soldered together in the proper sequence.

Since the RGB LED strip requires updating at very high speeds, this is addressed with a Serial Peripheral Interface or SPI bus. However, the GPIO libraries that RBPi uses with the “Wheezy” OS distribution are not fast enough. Therefore, Raspberry Pi needs a change of OS and must use “Occidentalis”, which is the Adafruit Raspberry Pi Education Linux distro, and includes the SPI support.

Occidentalis also has sshd that makes it easier to transfer images from a PC to the Raspberry Pi. sshd is the “secure shell” daemon server. It is like a secure version of telnet, allowing a user running the ssh client program on a local computer to connect to another (remote) computer running the sshd server, and logon to the remote computer. Unlike telnet, the communications are encrypted against network sniffers.

A Python Image module is used to convert the image transferred to the Raspberry Pi to an RGB format suitable for the LED display via the SPI devices. Instead of repeatedly processing each row or column of the image on the fly, the entire image is preprocessed into the hardware specific format suitable to the LED strip and stored in the memory of the RBPi as arrays. Refreshing the display is then only a matter of reading these arrays from the memory into the SPI port. More details of the hardware and software are available here.

The motion rig consists of a large PVC pipe bent into a ring on a hula loop. The LED strip is mounted on this and retained with zip ties. The ring assembly, batteries and the electronics is attached to the rear of a bicycle, which provides the motion. The entire arrangement including the bicycle must be painted matt black to be invisible in the photos.

For the power supply, 12V batteries have to be used, and a DC-to-DC converter is required for powering the LED strip and the electronics, all of which operate at 5V. The result of all this labor is limited only by your imagination.

4 Accessories to Turn your Raspberry Pi into a Workhorse!

Gert Board To Pair Up Your Raspberry Pi With The ATmega Microcontroller

You can now expand the General Purpose Input Output (GPIO) pins of your Raspberry Pi with a Gert Board. Gert Board is the brainchild of Gert Van Loo, one of the developers of the alpha version of the Raspberry Pi. With the addition of the 28-pin ATmega microcontroller, you have the entire Arduino Integrated Development Environment (IDE) at your disposal. Moreover, it is possible to add any of the following ATmega controller models to the Raspberry Pi – ATmega 48A/PA, ATmega 88A/PA, ATmega 168A/PA or the ATmega 328A/PA.

So, what does this mean for your Raspberry Pi? By adding the Gert Board, you get an 18V @ 2A port for your motor projects. You also get a 2-channel, 8-, 10- or 12-bit Digital to Analog converter along with a 2-channel 10-bit Analog to Digital converter. Additionally, you get 6-Open Collector drivers capable of 50V @ 0.5A, 12-Buffered I/O’s and three push buttons.

PiFace Digital Controller

If you intend to control external hardware via the Raspberry Pi’s GPIO header, the easiest way is to use the PiFace Digital developed by Andrew Robinson of the University of Manchester. The PiFace Digital has two onboard changeover relays, and this is the central feature of the add-on board. The changeover relays have open-and-close positions, which are accessible to the user. Each open-and-close position of the relay can handle 5V @ 10A maximum. You can program the board through Python, C or Scratch. Scratch has also developed an emulator, called the PiFace Emulator. This gives you a graphical control over the features of PiFace. Not only this, PiFace has additional onboard features such as eight digital inputs., eight open-collector outputs on connectors, eight LED indicator lights on the outputs and four tactile switches.

Pi Camera

The Raspberry Pi has an onboard CSI port, which you can connect using a ribbon cable to the Camera Module. The Raspberry Pi camera module measures only 25mm x 20mm x 9mm. The tiny module has an Omnivision 5647 fixed-focus module that can handle 5MP still images, while weighing only 3 gm. You must use a 4GB or larger SD Card on your Raspberry Pi, as this is where the images from the camera are stored. The camera can handle resolutions of 1080p30 (1080 pixels at 30 frames per second), 720p60, and 480p60/90. The CSI bus on the Raspberry Pi is capable of handling high data rates streamed directly to the processor on board (BCM2835 ARM 11).

A Slice of Pi

This breakout board, called the Slice of Pi, is the least expensive of all the expansion boards for the Raspberry Pi. The board has a serial peripheral IO port expander, MCP23017, which adds 16-input/output channels to your Raspberry Pi. Apart from this unique feature, you can also use the board as a custom development area. One key feature of this Slice of Pi is the Xbee style connector mounts. Since this can support the XRF, Xbee and the RN-XV wireless modules, the functionality definitely expands the popularity of the board. Apart from this, you have easy access to the on-board GPIO, the 3V3, 5V; GND and the TX/RX solder points.