GPS Serial Interface - Technical Question

[BadRambo]

I have scanned through the manual, and elsewhere, and cannot find the nature of the logic levels that the GPS interface uses. I am considering building a battery-portable unit using a 996 and integrating a GPS engine board. Most engine boards available have the choice of either TTL or RS-232 type levels for the interfaces.

I cannot find a spec on the 996 as to how they have designed the interface. Has anyone been through this exercise yet ???

Any help appreciated -- Thanks -- Bob

 

[UPMan]

The port on the 996 is an RS232 port.

 

[BadRambo]

Thanks UPMan. Well, if that is the case, then a TTL level interface is out of the question. The GPS unit must provide RS-232 level signals.

Thanks Much -- Bob

 

[Al42]

If you're building, a TTL-level interface and a MAX-232 would do the job.

 

[seamusg]

If you're building, a TTL-level interface and a MAX-232 would do the job.

Did you bother to READ upman's post that it must be RS232 or are you re- defining standards?

 

[crayon]

Did you bother to READ upman's post that it must be RS232 or are you re- defining standards?

seamusg,

IMHO, Al42 is one of the most astue and technically literate regular posters (amongst others) on rr.com. While this may sound insulting, (it isnt) ... you would do well to pay attention.



A MAX-232 converts RS232 to TTL, and vice versa. If, for whatever reasons, the OP really wanted to go with a TTL GPS engine board, he can still get his project working with a MAX-232.

HTH's

 

[UPMan]

Also, I can't guarantee that TTL won't work...but it has only been tested and "spec'd" to work with RS232 (some devices will happily run with either).

 

[BadRambo]

seamusg,

A MAX-232 converts RS232 to TTL, and vice versa. If, for whatever reasons, the OP really wanted to go with a TTL GPS engine board, he can still get his project working with a MAX-232.

HTH's

Hiya -- I am quite familiar with the MAX device and have designed with it in the past. Thanks for the input. The good thing is that the receiver units I am looking at are available in either format, either TTL or 232 output levels. At this point, with UPMan confirming the electrical interface of the port, it is a slam dunk.

Thanks Again -- Bob --

 

[Robert721]

so the GPS uses which pins on the 232 connector, 2, 3, & 5?

 

[crayon]

so the GPS uses which pins on the 232 connector, 2, 3, & 5?

I would think three and five for sure and two if you can dink with the GPS. ie: waypoints, etc. But I've never messed with that radio.