Thread: Serial GPS unit, does it use pin 8?

yeh that such work, as long as u dont need dts/rts handshaking, which u dont on gpses usually, they just send blind. infact all you need is the rx line from the gps serial, the other pins on the serial port can be used for other input/output. make sure the app your running for gps output doesnt use the other pins mind, if so you might need to write a simple app that creates a virtual com port for your gps app to access, and your app will just write whatever it sees on the serial rx line to your virtual comport, and ignore any writes to the virtual comport from ur gps app.

hope that helps

regards

matt brocklehurst

Originally Posted by LittleDragon

The motherboard I bought only has one serial port, is it possible to have the serial GPS unit plugged in and solder the 5V line from the power supply to pin 8 so I can use that as a shut down controller? I'm eventually going to use a USB gps unit, just curious of it would work or not.

Windows will only allow one app to control the com port, so I don't see this working...If you're using Windows

5v line to pin 8, how does that work?

Originally Posted by LittleDragon

just relay it with the ignition and setup a UPS. When you turn off the key, it'll cut power to pin 8 which makes windows think the UPS lost power and proceeds to shut down.

Ok, I thought you may have meant through a relay, that's how mine works....but Windows won't let you put both the USP service and another program (GPS) on the same com port.

Originally Posted by arkadiyp

thats not entirely true. You can write a layer that will be integrated with the comm port driver which will pass everything on without opening a port. That same layer can make a "fake" comm port made up of only pin 8, which your shutdown device will use.

Its the same principle on which ComPort Monitors work. I just wish I had all my bookmarks from my old HDD, I had a ton of links on the subject. But if you you'll be fine.

Well, he was only talking about connecting things, not writing 'layers'

I'd be very interested when you find your bookmarks, in the mean time, I'll google again....

And it's probably possible using a Virtual Com Port Splitter such as This, as long as the GPS software ignores pin 8. (and the UPS service ignores the pins that the GPS is using)