Primarily for general aviation discussion, but other aviation topics are also welcome.
By santon
#1358040
Hi

I have a permit plane with a Trio autopilot that needs an NMEA data source. Until now I have used the output from a Lowrance GPS. However I now propose to use Skydemon as my main GPS with a small AV8R as backup. As the data output from the AV8R uses a microUSB plug and I am forever having problems with bad connections with said plugs I would like another data source.

Would something like this

with the usb plug cut off to reveal the power wires and the NMEA output wires be the best solution please?
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By Paul_Sengupta
#1358042
No.

I would suspect you'd need a low baud rate serial connection. Can you not still use the Lowrance GPS for this?
By santon
#1358043
the Lowrance is a big lumpy thing and the panel space is now being used for the Nexus7.
By santon
#1358049
I could do but it is very heavy. The gps requirement as per the Trio EZ Pilot manual is:

Your GPS probably has a setup mode where you must enable the output. Some have
several possible output modes. The proper mode must be enabled for the GPS to
communicate with the autopilot. For the NMEA format the desired output is NMEA 0183
Rev 2.0 (or greater), 4800 baud rate, 8 data bits, no parity, 1 stop bit (8, N, 1). The
AVLINK is 9600 baud, 8 data bits, no parity, 1 stop bit (8, N, 1).
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By Paul_Sengupta
#1358050
Yes, sounds right. Having said no, it may just be possible to take that small unit apart and intercept the serial line before it goes into the serial to USB converter. But you'd need some additional buffer/voltage converting electronics even if you could find the correct place on the PCB. Interesting project though! ;-)

Alternatively you could just buy a smaller GPS with a serial output...
By santon
#1358051
Ah. Thanks. Lectrickery is beyond my bandwidth. Can I get a similar gps receiver thingy that will have a serial output?
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By Paul_Sengupta
#1358055
A quick e-bay search brings up this but it may need some interface circuitry depending on what the autopilot expects in terms of voltages.

Aha, another search brings up this and this.
By santon
#1358059
Thanks. The first seems pricey but the Sirf 3 is a more reasonable price.
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By Flyin'Dutch'
#1358062
I would like my autopilot to have a feed which was not dependent on some communal garden connectors.
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By Marvin
#1358185
wigglyamp wrote:A Garmin Pilot 111, GPS196 or 296 will all output the required NMEA signal and can be found cheaply second-hand.


I had that situation, a second GPS, and found it a pain. Not found any easy way of using the usb out from tablets and I do lecktrickery.

Ended ditching both and going for a aviation gps, Garmin or AVMap are good if you have the panel space and will undock for flight planning at home.

Until avionics like Autopilots catch up with today's world that was my solution.