Graphing calculators are nothing less than powerful pocket computers, capable of doing many of the same things as smartphones, desktops, and laptops. Given that they have reasonably fast processors, a display, memory, and ports to interface with the outside world, I set out to making graphing calculators capable of determining their location using standard GPS hardware. I started with the TI-84 Plus / Silver Edition series of graphing calculators, which have a 15MHz processor, a 96x64-pixel monochrome screen, rudimentary timers (as well as one 32KHz crystal timer), and perhaps most importantly, two ports to interface with the outside world. One is a USB OTG port, a mini-USB port capable of acting as either a host or device, and therefore capable of producing 5V for peripherals. The other is a "serial" I/O port with two bidirectional TTL-level data lines. For my project, I chose to use the USB port for power, and the I/O port to communicate with a TTL serial GPS module. I created both the hardware and software necessary to make the project a reality, then suffered through two weeks of trying to get a GPS fix amid the metal canyons of a major US city.

Along the way, the two major technical challenges I faced were building a serial library and powering the module from the calculator. Once I succeeded in building functioning hardware and software, and eventually got a video of the GPS device operating normally, I documented the project in the writeup, video, and pictures linked below. Enjoy, and I challenge you to try building this project as well!

More Information
GPS for graphing calculators documentation
Video of TI-84+SE receiving GPS data
GPS driver for TI-84+/SE



Cross-posted from this Cemetech topic

Soon, we will be able to use our calculator to track down our lost phones

Nice job Kerm

Wow, I expected this to be a joke post. That's pretty awesome Kerm!

I wonder if primitive navigation software could be loaded into the chip via Linux to generate B&W maps with the right screen size...

This is very awesome!
Maybe the next thing is Wifi for calcs

You'd just have to write the drivers, i mean, hooking up a wifi usb thingy is easy

>Enjoy, and I challenge you to try building this project as well!

Challenge accepted! (nice work btw)





Mine can stream <1cm resolution survey grade GPS data at up to 60-120 readings a second from 3 separate devices, has up to two internal 1km range Bluetooth radios, runs off 4 external AA batteries, can be run over by a truck without damage, has a screen that withstood the impact from a .22cal hollowpoint without damage, and is waterproof for 30 minutes at a 3 meter depth.  :-)

Of course, it also retailed for ~1500$US.

http://www.amerisurv.com/PDF/TheAmericanSurveyor_Pepling-DC50_April2007.pdf

Maybe the next thing is Wifi for calcs

I think this has already been done for the Nspire with the Linux port.

And doesn't the official Nspire wireless adapter use wifi?