We’ve been following the work of [Andrew Holme] and his homebrew GPS receiver for a while now. A few years ago, [Andrew] built a four-channel GPS receiver from scratch, but apparently that wasn’t enough for him. He expanded his build last year to track up to eight satellites, and this month added a Raspberry Pi for a 12-channel, battery-powered homebrew GPS receiver that has an accuracy of about 3 feet.
The Raspi is attached to an FPGA board that handles the local oscillator, real-time events, and tracks satellites automatically. The Pi handles the difficult but not time-critical math through an SPI interface. Because the Pi is attached to the FPGA through an SPI interface, it can also load up the FPGA with even more custom code, potentially turning this 12-channel receiver into a 16- or 18-channel one.
An LCD display attached to the FPGA board shows the current latitude, longitude, and other miscellaneous data like the number of satellites received. With a large Li-ion battery, the entire system can be powered for about 5 hours; an impressively portable GPS system that rivals the best commercial options out there.
How small is it? Two things should give you a good sense of scale, the SD card slot on the lower right, and the slide switch on the upper left. This minuscule module is an all-in-one GPS logger which [J3tstream] built.
Main system control is provided by a Teens 2.0 board. If you look really closely you’ll see the SD card slot is actually a breakout board which mounts on top of the Teensy’s pinheaders. Also on the board is a PA6B GPS module with a few passive components to support it. The back side of the board hosts a Lithium Ion battery from an old phone. Note the mangled pin header which works as connectors for the battery. [J3tstream] even built a charger into the project. He’s using an LTC4054 chip to handle the charging. We were a bit confused at first because we didn’t see a way to connect external power. But he goes on to explain that the USB port on the Teensy board is used for charging. Just plug in USB and press the button to get things started.
[Chris] has been hard at work building a Heads Up Display into some Snowboarding goggles. We’re used to seeing the components that went into the project, but the application is unexpected. His own warning that the display is too close to your face and could cause injury if you were to fall highlights the impractical nature of the build. But hey, you’ve got to start somewhere when it comes to prototyping. Perhaps the next iteration will be something safe to use.
A set of MyVu glasses were added to the top portion of the goggles, which lets the wearer view the LCD output by looking slightly up. The display is fed by a Raspberry Pi board which connects to a GPS module, all of which is powered by a USB backup battery. In the video after the break you can see that the display shows time of day, speed, altitude, and temperature (although he hasn’t got a temperature sensor hooked up just yet). His bill of materials puts the project cost at about £160 which is just less that $250.
Continue reading “Snowboard goggle HUD displays critical data while falling down a mountain”
A reverse geocache – a box that only opens in a specific geographical area – is a perennial favorite here at Hackaday. We see a ton of different implementations, but most of the time, the builds are reasonably similar. Of course dedicating a GPS receiver solely to a reverse geocache isn’t an inexpensive prospect, so [Eric] came up with a better solution. He’s using a smart phone as the brains of his geocache, allowing him to keep the GPS and display outside the locked box.
The build began by finding an old box and modifying it so it can be locked with a servo. The only other bits of electronics inside the box are an IOIO board, a battery pack, and an I2C EEPROM for storing a few settings. On the phone side of things, [Eric] wrote an Android app to serve as both the programming interface, UI, and GPS hardware for his reverse geocache. It’s exactly like all the other reverse geocaches we’ve seen, only this time the controls are wireless.
[Eric] put up a video demoing his reverse geocache. You can check that out after the break.
Continue reading “Putting the brains of a reverse geocache on the outside”
Cheap GPS modules
If you’re making a GPS-enabled project, you may have noticed the commonly available GPS modules are pretty expensive – usually around $50. Here’s one for $8. It’s a U-blox PCI-5S GPS receiver on a PCI Express card. There are test points for serial and USB data, though, so fitting this in your project is a breeze.
Grandfather clock makes a giraffe’s scarf
Here’s a clock project from [Siren Elise Wilhelmsen]. Over the course of 365 days, the clock knits a giant, 2-meter tube of yarn that should be the perfect start for a half-dozen pairs of socks. No video for this, but if you find one, post a comment.
A huge hackerspace for Hotlanta
Atlanta is getting a new hackerspace. It’s called My Inventor Club and they’re starting to move into their space. Judging from [Scott]’s pictures of the new space it’s huge. We can’t wait for the video tour once they’re done moving in.
Ardino and Windows 8
Windows 8 is… weird… and you can’t install unsigned drivers without a lot of rigamarole. This means installing the Arduino IDE is a pain but [Dany] has a solution. Reboot into “test mode” and you can install unsigned drivers without your computer throwing a hissy fit.
Tweet for welts and bruises
[Zach]’s boss told him to come up with a Twitter-controlled paintball gun. Why he was asked to build this is beyond us, but the build is still cool. It’s powered by an Arduino and was built in just 12 hours. If only there was a video stream…
Hey guys, need some help here.
Alright, I’ve got a little problem with component sourcing. I’m making a ‘shield’ for the Raspberry Pi. Does anyone know where I can get really long female headers for the GPIO pins so the board will fit over the USB and Ethernet jacks? Here’s the project if you’re curious. I think the female part of the header needs to be 14mm high at least to fit over the USB port.
EDIT: Samtec ESQ-113-33-L-D. Here’s their site. This site is amazing. You can actually… find things. Completely unique experience here. Thank you, [Richard].
[Michael] posted up-to-date GPS data sets in the GPX format. These data sets are an alternative to paid updates. Since GPX is a published standard which uses an XML style formatting for location data [Michael’s] time was spent getting the original sets and finding a way to translate them for his Garmin EXTREX GPS.
The original data comes from — hang on, this is a mouthful — the US Federal Aviation Administration’s Facility Aeronautical Data Distribution System (FADDS). He had to apply for permission to download it and to use it in producing a custom GPS build. He grabbed the Airport waypoints and navaid sets, then studied accompanying files detailing the data structure before writing his own Visual Basic 2010 program to spit out the GPX files. He says he wanted to make them available in the spirit of the Open Hardware/Software movement. This may be most interesting for pilots (the kind that put Nooks on the dashboard, not the kind who watch the aircraft from the ground), but we’re sure there’s a myriad of uses for non-pilots alike.
If you’ve ever worried about your car getting stolen this hack can help give you some piece of mind. It’s a cellular enabled geolocation device. These things have been in use for some time, the most common brand we know of is the LoJack. That company gives you a little box to install on the vehicle and if it ever goes missing they can grab the coordinates and forward them to the authorities. This custom version builds a lot into an addon board for an EFM32 board.
The image above shows the main components of the add-on: the GPS module and the GSM modem. Along the top edge of the board is the voltage regulator circuits which aim to keep the standby power to the slightest of trickles so as not to drain the car’s battery. What you can’t see is the SIM card slot which is located on the underside.
You can find the Eagle files for the design at the link above. We’ve embedded the video description of the project after the break.
Continue reading “Roll your own LoJack clone”