I just bought EM-402 from sparkfun.
It worked fine at 4800 bps but when i played around with the settings in
this program http://www.usglobalsat.com/downloads/SiRFDemo.exe
that deals with reciever uart in the module and it doesnt transmit data anymore! Ahh what should I do now! I played with the UART config settings and it even explicticly said not to mess with it. I did any way. Now I can’t communicate with the module and worse still cant get any data from the transmit lines with diferent baud rates and the damn thing is still recieving data from satellites cause the stupid led blinks but no data on the transmit. :evil: :evil: :evil: I wish I can return the thing and get another one but I already soldered the unit. What should I do??
Sounds like you screwed it up yourself - I don’t see why SF should accept a return in that case anyhow.
You could try sticking a scope on the lines and see if you can identify how the data is going out - it might be with a strange parity / baud rate / stop bit settings that your computer doesn’t support.
You could also try removing all power to the device [if you have a lithium backup battery on it] to see if that will clear its settings.
–David Carne
I have messed around with the mentioned program before with an ET-301. It has its quirks (the software). Try hooking back up to the serial port with the software. Then from the software, mess around with the Protocol. Switch it back to NEMA, et cetera…
Getting rid of all the power should reset the chip. This means disconnecting the battery (if convenient), or shorting it out briefly. There is a similar discussion with the bluetooth receivers on the gpspassion forums. I’m not familar with this particular board, but I’ve had to reset my Sirf based Holux gps236 a couple times. (I learn slowly.) Besides changing the serial port configuration, you can get in trouble with the Sirf power configuration. If the chip is on really, really low power mode, it isn’t awake long enough to receive commands.