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Re: New GPS units additional NMEA prefixes
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I don't think a translator is necessary for many of the newer GPS receivers. The output difference for NMEA sentences "we are interested in"? is just the second letter: uBlox M8N $GNRMC,140843.000,A,4209.3513,N,08346.2741,W,0.08,,070520,,,A*7C $GNVTG,,T,,M,0.08,N,0.1,K,A*04 $GNGGA,140843.000,4209.3513,N,08346.2741,W,1,12,0.8,237.9,M,-34.6,M,,0000*70 $GNGSA,A,3,04,09,27,16,08,07,26,,,,,,1.7,0.8,1.5*22 $GNGSA,A,3,80,71,73,82,70,81,72,,,,,,1.7,0.8,1.5*2D $GPGSV,3,1,10,04,59,198,35,07,30,299,28,08,44,167,32,09,58,276,31*74 $GNDTM,W84,,0.0,N,0.0,E,0.0,W84*71 Older GPS: $GPRMC,141055.00,A,4209.34960,N,08346.27475,W,0.078,,070520,,,A*64 $GPVTG,,T,,M,0.078,N,0.144,K,A*2D $GPGGA,141055.00,4209.34960,N,08346.27475,W,1,08,1.00,232.5,M,-34.6,M,,*64 $GPRMC,141055.10,A,4209.34960,N,08346.27476,W,0.072,,070520,,,A*6C $GPGGA,141055.10,4209.34960,N,08346.27476,W,1,08,1.00,232.5,M,-34.6,M,,*66 $GPGSA,A,3,04,09,27,16,08,07,26,11,,,,,1.75,1.00,1.43*02 $GPVTG,,T,,M,0.024,N,0.045,K,A*24 So, direct comparison:? (uBlox then Old) $GNRMC,140843.000,A,4209.3513,N,08346.2741,W,0.08,,070520,,,A*7C $GPRMC,141055.00,A,4209.34960,N,08346.27475,W,0.078,,070520,,,A*64 $GNGGA,140843.000,4209.3513,N,08346.2741,W,1,12,0.8,237.9,M,-34.6,M,,0000*70 $GPGGA,141055.00,4209.34960,N,08346.27475,W,1,08,1.00,232.5,M,-34.6,M,,*64 If you import them to a spreadsheet and put them in columns, they all match up. Seems like a simple split of the $GsMSG and ignore the second character would provide all the data, no matter source - at least for the RMC and GGA.? Doesn't sound like that big of a change KB8RCO On Thursday, May 7, 2020, 02:06:35 PM EDT, vhsproducts via groups.io <vhsproducts@...> wrote: I would be happy if the TT3 just ignored the GLONASS sentences, and just accepted the NMEA sentences. It does not appear that the plethora of inexpensive GPS receivers out there can let you deactivate the GLONASS ( Damned Commie sentences!) and the multiple format coming from these will not work with the TT3. Its a shame, because these GPS receivers tend to be very cheap, especially in Europe. ( Cheap by EU standards at any rate)? The tendency is also to produce GPS receivers with lower supply and output voltages. This can be a problem for any equipment that has relied upon TTL voltage level serial ( Not RS-232) Many of these new receivers are insanely small! Unfortunately, almost none of the new generation of GPS receivers will violate the COCOM altitude limitations, no matter how much you scream at the manufacturers that it is a minor and perfectly legal code change. The Byonics GPS receivers, both the "Hockey Puck" and the OEM unit, are available in a high altitude version for all the HAB people ( High Altitude in the minds of the people who keep us from building our own cruise missiles is 60,000 feet) The OEM unit has "true" serial ( I don't even know for sure what that means anymore...) and 5 Volt TTL, both of which are fully TT3 and TT4 compatible.? I am going to assume that someone out there in code-land is going to produce a sentence translator as a PIC for these weird GPS receivers. I have been disappointed in making such assumptions before...Like hoping we would find a MAC genius who would build an Apple configuration program for us out of the goodness of their hearts! ( Damned Apple Commies!) 73, Allen AF6OF -----Original Message----- From: Rob Giuliano via groups.io <kb8rco@...> To: [email protected] Sent: Thu, May 7, 2020 9:53 am Subject: Re: [TinyTrak] New GPS units additional NMEA prefixes I have to admit. I haven't used a TT3 since getting the MTT4B. So only really concerned about the TT4. So I have 2 (or maybe 3) TT4s and the MTT4B (used most). What I am unsure of, is what impact the change from Combined to GPS has. Does it ignore the GLONASS infomration, or still use it and just put out the message as GP. Best guess is that it doesn't use the GLONASS information - kind of a waste. Robert Giuliano KB8RCO On Thursday, May 7, 2020, 12:33:29 PM EDT, vhsproducts via groups.io <vhsproducts@...> wrote: Robert, Never mind, I just Googled it. You will have to convince Byon to do an upgrade for the TT4. I don't think it is even possible with the TT3.? 73, Allen AF6OF -----Original Message----- From: vhsproducts via groups.io <vhsproducts@...> To: kb8rco@... <kb8rco@...>; [email protected] <[email protected]> Sent: Thu, May 7, 2020 9:18 am Subject: Re: [TinyTrak] New GPS units additional NMEA prefixes Robert, Is this a dual-band (NMEA+GLONASS) GPS receiver? 73, Allen AF6OF -----Original Message----- From: Rob Giuliano via groups.io <kb8rco@...> To: [email protected] Sent: Thu, May 7, 2020 7:53 am Subject: [TinyTrak] New GPS units additional NMEA prefixes I just pulled my MTT4B out again and connected it to a new uBlox M8N GPS module. ? Settings: 10Hz update with output at 19200,n,8,1 I see the GPS sentences in a terminal, but the Green LED never flashes or comes on solid. I plugged in my older GPS, and everything is fine. ? Settings: 10Hz update with output at 19200,n,8,1 Then I realized the NMEA sentences all started with 'GN' instead of 'GP'.? Digging deeper, I found that uBlox configuration (u-center) allows you to change the "main talker" to 1-GPS (default is 3-Combined).? Don't forget to go to the CFG option to permanently set this value, or it will reset on power up.? Only difference appears to be the second letter.? Any chance of a future firmware update to handle more options? Current prefixes are: GP, GL, GN, GA, and GB. Robert Giuliano KB8RCO |
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