Automatic Position Reporting System (APRS) is used to transmit location and other real-time data over amateur radio frequencies. [Scott Miller]’s OpenTracker project is designed to encode the NMEA data from a serial GPS receiver for transmission. It doesn’t have to be used for GPS telemetry though, you could hook up a weather station or any other remotely located project. Scott has boards, parts and even full kits available.
[jcoxon] was inspired by the original Linux weather balloon project. His Pegasus 1 reached an altitude of 66,585ft and took over 600 pictures. The flight logging system is based on the Gumstix waysmall computer system. It captures data from the GPS receiver and controls two cameras. There are photos from both a downward facing camera and a side facing camera. Periodically the last three GPS entries are sent to Jame’s cellphone via SMS; this made recovering the payload a lot easier. There is already a second baloon planned.
[Barry Carter] had a Pretec compact flash GPS adapter for his PDA and really liked how it worked. The problem was it took up the CF slot so he wasn’t able to add any flash memory to the device to store larger maps. He opened up the device and discovered that it only had five wires attached to the compact flash portion. The lines came from an NMEA chip and he used a scope to figure out the port settings. All that was needed was an RS232 converter. With the new packaging he was able to plug the GPS portion into the PDA’s serial port and use a larger CF card for storage.
[Chris Barron] is getting pretty unnerved by the UK moving to charging for road use based on GPS coordinates. He built this device to prove that GPS data can be spoofed and shouldn’t be relied upon. He promises future firmware updates that will provide two knob etch-a-sketch style path control.
[stok] built this GPS receiver from the ground up. The GPS module he got off of eBay dumps NMEA 0183 data. He combined that with an old Nokia LCD and a PIC microcontroller. I like this project because it shows that you can build devices that the general public assumes are really complex.
Here’s a short guide for converting a Palm III GPS sled into a normal serial GPS receiver. The Palm III is old tech so its accessories can be picked up cheap and modified for other purposes. The GPS receiver needs to be separated from the Palm specific board and a few components need to be transfered between the two. Once that’s done you should have a standard serial GPS receiver. Here’s a cache in case the “Read” link fails.
[thanks nevamore, who has done this hack with success]
this site shows you how to jack in to the gps receiver inside any gm onstar system. it’s as simple as soldering a up a serial cable. you can then connect to it and either run some gps diagnostic software, or switch the device to nmea mode so that you can use it with your gps mapping software in your car pc.
if you’ve got an onstar system but aren’t paying for the service this might be just the hack for you. thanks for the link leo!
