I have found the Air530 manual in Chinese. Is there any hope of one in English? If not, what command do I need to transmit to change from Beido to GPS or Glonass? Is there anything else that I need to send to start transmissions?
You can send a Chinese PDF file to Google to translate it. I do it all the time. The Air530 command you are asking for is $PGKC115 with 4 binary (0 or 1) arguments that represent turning on the appropriate mode.
The first argument turns GPS on.
The second argument is for GLONASS.
The third argument is for Beidou.
The fourth argument is for Galieo.
So to turn GPS (and only GPS) on you set the 1st argument to 1 and send the following:
*$PGKC115,1,0,0,0 * 2B *
To turn on BOTH GPS + BEIDOU you set the 1st and 3rd arguments to 1:
*$PGKC115,1,0,1,0 * 2A *
To turn on BOTH GPS + GLONASS you set the 1st and 2nd arguments to 1:
*$PGKC115,1,1,0,0 * 2A *
I assume you know how to calculate the CRC checksum at the end (the 2B and 2A before the end) and that you need to send both the carriage return ‘\r’ and line feed ‘\n’?