I'm currently trying to connect a Honeywell DRM4000L to a GPS module. The DRM is a dead-reckoning device which takes a GPS input and outputs the location by serial. Currently, I have a GS407 GPS module connected to the DRM. Every time I try the GPS pass-through function on the DRM, I get gibberish output.
I also have an FTDI cable connected to the GPS and I'm getting the correct NMEA data. The data coming in from the GPS is all formatted correctly when connected directly to the computer. The DRM data is also coming in correctly, but it doesn't see an NMEA data stream and thus does not initialize with the GPS data. It only has track information based off of the inertial sensors.
The GPS is set to 9600 baud and the DRM host port is set to 9600, so the DRM should be seeing all the correct GPS data. The baud rate from the DRM to the computer is also 9600.
Is anyone seeing anything that I'm not seeing? Thanks!
Moved to Electronics StackExchange. The problem was that the DRM is using RS-232 while the GPS is using TTL, thus causing the incompatibility between the two modules. A MAX3232 or MAX232 is used to convert these voltages.
Link to complete post: https://electronics.stackexchange.com/questions/95153/honeywell-dead-reckoning-module-gps-problems