SparkFun Forums

[gravityfreak99]

Anyone have any tips on getting the EM-406 to spit out SiRF binary data? According to everything I've read, it should be as simple as selecting the "Action -> Switch to SiRF Protocol" menu option in SiRFDemo.

I'm using the EM-406 and the SFE Breakout board, and I get NMEA data on COM1 at 4800bps, but when I try to switch to the SiRF protocol, it ignores me and continues spitting out NMEA messages.

[forthguru]

You seem to be having the same problem as I.
I have been playing with the little beast for a few days now using SiRFDemo and I have not yet worked out how to "reliably" switch it between modes. With a lot of playing I can get it to switch, but I haven't yet worked out the exact way to hold my mouth to make it happen every time. Hope someone can explain.

[seulater]

I am not sure what version of the SiRFDemo your guys are using.
the one i have v3.751 has "Switch to NMEA Protocol" & "Switch to SiRF Protocol" under the "Actions" menu.

i have never had trouble switching back and forth with this version.

[NleahciM]

What is the benefit of the binary protocol?

Also - is it possible to switch to the binary protocol without the demo program?

[ohararp]

In theory you can use the binary protocol but a couple of users at the usglobalsat forums have talked about how the sirf binary protocol can be a bit spotty to deal with. Definitely use the checksum values and error checking to make sure data was sent back and forth.

[gravityfreak99]

forthguru: I've never been able to get it to switch at all. Good luck, and if you figure something out, post it here please!

seulater: I started out with a previous version of SiRFDemo (maybe 3.75?) and had no luck so I upgraded to the most recent version I could find (v3.81) and still am having no luck.

[gravityfreak99]

I'm beginning to think my serial port is being flakey. In addition to playing with the GPS module, I'm also working at learning to program AVR microcontrollers. I'm also having problems getting AVRStudio to connect with my STK500 programmer using the serial port.

It's odd that I can receive data on the port (i.e. NMEA data from the GPS) but things that involves sending data via the port seem to fail. It's not a bad cable (I've tried several). This computer's been in operation for a year or two... might be time to clean the computer off and reinstall Windows.

[gravityfreak99]

I'm beginning to think my serial port is being flakey. In addition to playing with the GPS module, I'm also working at learning to program AVR microcontrollers. I'm also having problems getting AVRStudio to connect with my STK500 programmer using the serial port.

It's odd that I can receive data on the port (i.e. NMEA data from the GPS) but things that involves sending data via the port seem to fail. It's not a bad cable (I've tried several). This computer's been in operation for a year or two... might be time to clean the computer off and reinstall Windows.

Ahhhh... confirmation! I switched over to another computer (which I've not been using because of other issues) and it has no problems switching the GPS over into the SiRF protocol. It can also communicate with my STK500 programmer as well. #@$& computers!!!

[seulater]

you guys are level shifting the RS232 to 5v right ?

FYI, you cannot pump raw RS232 signals from your computer straight into the GPS module.

[gravityfreak99]

you guys are level shifting the RS232 to 5v right ?

FYI, you cannot pump raw RS232 signals from your computer straight into the GPS module.

Yeah, I'm using the SparkFun eval board, which has a MAX3232 IC to do the RS-232/TTL translation. Apparently my problem is either with Windows or my computer hardware itself.

Thanks for the sanity check though!

[seulater]

ok, cool.

ya, windows can act like an old moody woman with Alzheimer's at times.


No offense to the ladies


P.S. you should try connecting together the 5v level side input to the output. this way whatever you type on the terminal program should be echoed back. at least you can verify that the data send is the same data returning to prove your windows serial connection is working properly.

Also, dont forget to connect the GND of that level converter board to the GND of the GPS module.