I am currently attempting to receive a serial NMEA GGA string from the Data Port. I have wired up a Sparkfun RS232 shifter (PRT-00449) to the Data Port pins. I have the Rx LED flashing on the RS232 shifter but no legible data appearing on my Serial Comm Terminal program. I am able to see the correct GGA string format coming over the Bluetooth channel but not the Serial Terminal program. It appears that any changes I make are only applied to the Bluetooth channel. There appears to be multiple data strings with Break Characters in between them on the Terminal Program. Sometimes it looks as if they are Hexadecimal as well. I have double/triple checked the baudrates, port configurations, data output selections, etc! Any other suggestions or a step by step process would be greatly appreciated. Thanks.
I’d be worried about exceeding the rs232 max throughput (~20kbps according to wikipedia)/max wire length for a given baud rate…the baud might need to be lowered, which can cause buffer overruns :-/ https://docs.sparkfun.com/SparkFun_RTK_ … ure_ports/
So…3 things:
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Is there a reason bluetooth or wifi can’t be used?
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Can you test the rs232 adapter with another sensor’s output to verify it’s working correctly? How long is the cable?
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Do you have a different way of interfacing? USB via u-center, different style of level shifter, etc…we recommend serial radios like these https://www.sparkfun.com/products/19032
but no legible data appearing on my Serial Com
Are you receiving anything at all? What sort of serial port does your computer have? Can you supply photos showing how things are connected?
To answer some questions asked:
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Bluetooth data seems to not want to play nice when other high CPU usage programs are running.
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Data output cable to RS232 shifter is 4 inches. RS232 cable to computer is 8 ft.
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We have not tried any other RS232-TTL converter yet.
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Currently we are attempting to go from Facet USB thru a USB-RS232 converter cable and then into the computer COM Port.
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We only need the NMEA GGA string so I don’t believe buffer over runs should be a problem.
I have attached two screenshots of simultaneously acquired data, one of the data coming over the bluetooth and the other of the data coming from the data port. The dataport.jpg is the data file stored by a COM program and opened via Notepad.
Thanks,
Chet
