Building The Slimmest Raspi

slim_pi

[Colin], AKA [Domipheus], was working on a project to monitor a thermostat with a wall mounted Raspberry Pi and a touchscreen. Simple enough, but the Pi has a problem: The plugs are all around the perimeter of the board, and with a TFT touch screen shield, it’s a bit too thick to be wall mounted. What followed is a hack in the purest sense: [Domipheus] removed and relocated components on the Pi until the entire Pi/display stack was just a hair over 10mm tall.

A Raspberry Pi Model A was used for this build, meaning the Ethernet jack was gone, and there was only a single USB port to deal with. Still, the highest components – the RCA and audio jacks – were too tall and needed to be removed; they weren’t going to be used anyway.

After these components were gone, [Domipheus] turned his attention to the next tallest parts on the board: fuses, caps, and the HDMI port. For fear of damaging the surrounding components when removing the HDMI connector the right way, this part was simply hacked off. The large tantalum cap near the USB power connector was removed (it’s just a filter cap) and the large protection diode was moved elsewhere.

Slimming down a Pi is no good without a display, and for that [Domipheus] used this touchscreen thing from Adafruit. Things got a little complicated when the project required the ability to remove the LCD, but you can do amazing things with a DIP socket and a file.

The end result is a Raspberry Pi with touchscreen display that’s just a smidgen thicker than a CD case. It’ll fit right up against a wall in its repurposed enclosure, and the end result looks very professional.

[Thanks Luke via reddit]

The Lightgame Project: A Multiplayer Arduino Game

lightgame_3Summer is upon us. The Lightgame Project is a multiplayer reaction time based game built around the Arduino. It’s a perfect rainy day project for those restless kids (and adults!). Designed by two undergraduate students [Efstathios] and [Thodoris] for a semester long project, all the hard work has already been done for you.

There are tons of reasons we love games that you can build yourself. For one, it’s an amazing way to get children interested in hobby electronics, making, and hacking. Especially when they can play the game with (and show off to) their friends. Another reason is that it is a perfect way to share your project with friends and family, showcasing what you have been learning. The game is based on your reaction time and whether or not you press your button when another players color is shown. The project is built around two Arduinos connected via I2C. The master handles the mechanics of the game, while the slave handles the TFT LCD and playing music through a buzzer.

I2C is a great communication protocol to be familiar with and this is a great project to give it a try. [Efstathios] and [Thodoris] did a great job writing up their post, plus they included all the code and schematics needed to build your own. It would be great to see more university professors foster open source hardware and software with their students. A special thanks goes out to [Dr. Dasygenis] for submitting his student’s work to us!

[Read more...]

Sink Your Teeth Into PiPhone

Raspberry Pi cell phoneHave you ever dreamed of independence from smartphone bloatware? If you have a Raspberry Pi and an Adafruit TFT, you’re halfway to making your own version of [Dave]‘s PiPhone.

This tasty proof-of-concept cellular sandwich is made by adding a Sim900 GSM/GPRS module, which communicates via UART, to the Pi/TFT hardware while using a piece of foam core board in the middle to prevent shorts. You won’t get free service or anything, but you can pop a pre-paid SIM card into it. He’s powering it with a LiPo battery and using a DC-to-DC converter to set up the 3.7V to 5V. You could do a lot worse than the $158 BOM, and we’re betting you have a Pi lying around already. We wish more phones had baby rocker switches.

There’s a slight problem with the PiPhone: it gets pretty warm and there isn’t a lot of room for air circulation. For best results, let it cool on a well-attended windowsill or operate it near a fan like [Dave] did. He doesn’t have the code up on GitHub as of this writing, but he will capitulate to high demand. Make the jump to see [Dave]‘s tour of the PiPhone and watch him make a call with it.

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Generating Embroidery with an Arduino

Arduino Embroidery Generation

Want a nifty way to combine the craft of embroidery with electronics? The folks working on the open source Embroidermodder demoed their software by generating an embroidery of the KDE logo using a TFT screen and an Arduino.

Embroidermodder is an open source tool for generating embroidery patterns. It generates a pattern and a preview rendering of what the embroidery will look like when complete. It’s a cross-platform desktop application with a GUI, but the libembroidery library does the hard work in the background. This library was ported to Arduino to pull off the hack.

While generating pictures of embroidery with an Arduino might look neat, it isn’t too useful. However, since the library has been ported it is possible to use it to control other hardware. With the right hardware, this could be the beginning of an open source embroidery machine.

After the break, check out a video of the pattern being generated.

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Easy LCD control for Arduino Mega

arduino-mega-easy-lcd-adapter

[Andy Brown] wrote in to show off the TFT LCD adapter he’s been working on for connecting inexpensive displays to an Arduino Mega.

These TFT LCD screens can be picked up on eBay for a few dollars. But they’re more suited for 16-bit microcontrollers which operate at 3.3V levels. His adapter board, which plugs directly into the Mega’s dual-row pin header, makes it easier to control these with an 8-bit chip that is running at 5V.

There’s a couple of things that make this happen. First off, he’s included level converter chips to managed the 3.3V/5V issues. Second, he uses latch chips to translate eight pins on the Arduino Mega to sixteen pins on the display. Those chips have a latch pin which holds the output values in memory while the input pins are changed. He manages to drive the latch on just one of the chips using the chip select (CS) line called for by the LCD protocol. This means you don’t lose any extra pins.

Another way to uses the displays with Arduino is to use a smart controller for TFT screens.

[Read more...]

Arduino cellphone

OLYMPUS DIGITAL CAMERA

The fact that you can build a cellphone around an Arduino is pretty neat. But we’re drawn to this project more as a testament to the advancement of hobby electronics. An [Average Joe] can build this thing with a minimum or background knowledge and without breaking the bank. Wow.

Of course this isn’t the first DIY cellphone we’ve come across. One of our favorites is this one which resides on a home etched PCB. There was even another Arduino offering with similar components back in September. But the one seen above really pulls it all together into a package that is usable for everyday life. The components include and Arduino Uno, GPRS shield from Seeed Studios, a TFT touch screen, Lithium battery and charging circuit, and a few other bobbles. All of it is mounted inside of a 3D printed case.

A simple phone calls for a simple UI and that’s included as well. The main menu has two buttons, one for placing a call, the other for sending a text. From there you get the virtual keypad seen above for typing out the phone number or composing a message.

[Thanks Victorzie]

Bluetooth Network Monitor

Bluetooth Network Monitor

[Zak] wanted to keep tabs on his network connection without needing to log into his router. Since his router was a PC running Debian Linux, he rigged up a Bluetooth Network Monitor to display the information.

The monitor is based on a ATMega328P that reads data from a Bluetooth serial connection and displays it on the TFT screen. It uses a low cost Bluetooth module to receive data from a router. A shell script fetches the data and formats it into a string that can be sent over the Bluetooth link.

A USB connection with a desktop computer is used to power the device, but [Zak] also added USB support using V-USB. He plans to use it to get data from the desktop. For example, he could display CPU load and temperature data.

Overall, this is a nice project for fetching data wirelessly and displaying it on your desk. [Zak] has provided the code and Eagle files with his write up for anyone interested in building their own.