SparkFun Forums

[ekoy]

How do you set up the GPS receiver (em 406 module) to get only DGPS data?? cause what i notice it is switching from GPS data and DGPS data which i dont want.. I want my GPS receiver to get only DGPS( this was base on the NMEA data GGA message the Position Fix Indicator which i notice it changes from time to time). Is it possible?

[cherreram]

Hi,

I was reading EM406's datasheet and I noticed it does DGPS using RTCM protocol, see NMEA INPUT COMMAND C).
So, what it means... first, to obtain navigation under DGPS you will have to have a reference station base with RTCM output capabilities (very expensive). Second, a data link to feed EM406 with RTCM data outcoming from reference base station and third, in NMEA.GGA, if everything work fine, you will see FIX=2, that means EM406 is working with dgps correction.
You say fix is changing from time to time...mmm...strange...because datasheet say nothing about other dgps sources capabilities (WAAS, EGNOS) on EM406... so, if there are not RTCM data in port B, fix always has to be 1 or 0.

Hope this help you a little.

cheers.