[zxatnep]

The gps module for the Pentax K-30 is very expensive especially if you only want to use it occasionally. Recently I was on a trip from Toulouse via Aigues Morte to Valence in France and at the end of the trip I basically had no idea exactly where on the canals and river Rhone the photos were taken. A gps unit would have been very handy. My question is...has anyone thought of or tried to make a workable gps using one of the $35 Opteka modules sold on eBay and the pentax off camera flash cord, again sold on eBay for $14. One end of the flash cord could be cut and wired to the USB cord connecting the flash foot to the gps module...Total outlay about $50...Any suggestions. Thanks

[SteveB]

You would need hacked firmware that could read the GPS data and write it into the EXIF. Not very likely.

I could take my Samsung WB650 and take one shot at the same location to get the coordinates but that's cheating.

[jatrax]

I don't think it is that simple, but maybe I'm missing something. The Opteka module is for Nikon, so even assuming your idea for wiring a cable up works you also have to assume Pentax and Nikon are using the same data protocols. Possible I suppose, but extremely unlikely IMHO. However, it has been done with Nikon, here is a link to someone who hacked together a GPS for their Nikon: Nikon D90 Homemade GPS

Another solution, that is less money than the Pentax solution is to get a GPS data logger. WIntec makes one as do others. There are also smartphone apps that will produce a GPS track. This track can then be fed into Lightroom to match with your images or this can be done with other software such as geosetter. These loggers are small and can just be added to a backpack strap or your camera strap. That is an advantage since there are no cables to the camera and the flash shoe is free if you want to use flash. You have to go to the trouble of saving and importing the gps track though.

I got the Pentax O-GPS1 when it was on sale in April and for $200 I am very satisfied. Just slide it on and forget it. Works flawlessly.

[zxatnep]

Yes, I have an app on my android that will log my route and software that will use the time settings to place the photos taken along that route. I can also buy a usb logger for $30 that will achieve the same result. The output from GPS modules all follow the Nmea protocol. I would have to keep connecting and switching wires until I found the correct combo (I hope). I have wired up a GPS unit for a Nikon D300 to work on my D7000 (10 pin to usb). Anyway just a project I may try. I obviously have too much time on my hands. Thanks

[Docrwm]

Yes, I have an app on my android that will log my route and software that will use the time settings to place the photos taken along that route. I can also buy a usb logger for $30 that will achieve the same result. The output from GPS modules all follow the Nmea protocol. I would have to keep connecting and switching wires until I found the correct combo (I hope). I have wired up a GPS unit for a Nikon D300 to work on my D7000 (10 pin to usb). Anyway just a project I may try. I obviously have too much time on my hands. Thanks

Sounds interesting, please keep us informed.

[Pepe Le Pew]

Sounds interesting, please keep us informed.

Resistance is Futile.....

Love the quote

[agaurav]

Hi all,

I am a part-time embedded firmware engineer with access to hardware/ASIC engineers. It would be a great project to hack something together. GPS modules can be bought for ~$30 these days. As the OP said, it would be great if somehow the communication protocol can be exposed to hack up something for the Pentax systems.

Is anyone crazy enough to have tried to reverse engineer the protocol? The idea is not only cost saving but also a sense of accomplishment :-)

[lister6520]

Hi all,

I am a part-time embedded firmware engineer with access to hardware/ASIC engineers. It would be a great project to hack something together. GPS modules can be bought for ~$30 these days. As the OP said, it would be great if somehow the communication protocol can be exposed to hack up something for the Pentax systems.

Is anyone crazy enough to have tried to reverse engineer the protocol? The idea is not only cost saving but also a sense of accomplishment :-)

I think it shouldn't be too difficult to reverse engineer the protocol between the camera and the GPS but of course you first have to buy an OGPS-1 to do that. It is most likely sending the unaltered NMEA stream serially. I don't see them having the need to develop any specific protocol, in their shoes I would just have the unaltered NMEA output from an off the shelf GPS chip sent to the camera. The camera firmware could easily recognise that it is a GPS unit rather than a flash and react accordingly.

If it is not just standard NMEA it will be a bit more laborious to reverse engineer but no enigma for sure. I say so because I've had a try at reverse engineering the flash protocol and made considerable progress in not too much time. I can see the settings, the result of the preflash and many other things. If I were to spend some more time on it I could probably even build up a compatible P-TTL flash. The GPS is bound to be simpler, first because unlike a P-TTL flash it is a one way communication - it just streams data towards the camera and secondly because GPS protocols already exist and are pre packaged in off the shelf chips so there would be no point in expending effort on developing a new one.

The only 'non-standard' part of it would be the hardware level of the communication - the one/zero voltage levels and so on, but these are easily determined with a digital scope.