Does anyone know where I can get documentation for sending commands to the ET-312 SiRF III GPS Receiver? The manufacturer’s website states that the GPS is capable of various baud rates and capable of sending either NMEA 0183 sentences or SiRF binary data but I don’t find an API command reference anywhere.
yes.
The SiRF proprietary binary commands are in a document that is obtained by non-disclosure agreement with SiRF. There are old, out of date versions floating around the 'net.
NMEA 0183 is open. But changing the baud rate, choice of sentences, non-standard senteces, sentence rate, power management, and so on are normally proprietary messages.
I haven’t received a response from Globalsat. Do you have any links to older versions which might let me just limit the NMEA 0183 sentences to the RMC sentence?