RoboSavvy Forum

GPS for MRC?

2008-07-17T23:29:10+01:00

Yep the NMEA protocol is known to me, i am struggling due to the fact that MRC has many limits - which are not visible to normal 'robo' users - but are stopping the hardcore developers.

And so on, to allow my UAV to be guided via GPS i need to buy gumstix board with few serial ports and GPS extension - and then plug it to MRC.

Even though i love RN1

Grr...

Statistics: Posted by roboTT — Thu Jul 17, 2008 11:29 pm

GPS for MRC?

2008-07-17T19:29:08+01:00

I think you may still struggle. The bluetooth in the RN-1 is still relient on the serial port I believe. Plus NMEA data from a GPS is a standard that is pretty verbose, and sent at 4800 baud. Infact it is not possible to send a complete cycle of NMEA data in 1 second due to the baud rate restriction.

Anyhow, the NMEA data packets look like this

$GPRMC,183729,A,3907.356,N,12102.482,W,000.0,360.0,080301,015.5,E*6F
$GPRMB,A,,,,,,,,,,,,V*71
$GPGGA,183730,3907.356,N,12102.482,W,1,05,1.6,646.4,M,-24.1,M,,*75
$GPGSA,A,3,02,,,07,,09,24,26,,,,,1.6,1.6,1.0*3D
$GPGSV,2,1,08,02,43,088,38,04,42,145,00,05,11,291,00,07,60,043,35*71
$GPGSV,2,2,08,08,02,145,00,09,46,303,47,24,16,178,32,26,18,231,43*77
$PGRME,22.0,M,52.9,M,51.0,M*14
$GPGLL,3907.360,N,12102.481,W,183730,A*33
$PGRMZ,2062,f,3*2D
$PGRMM,WGS 84*06
$GPBOD,,T,,M,,*47
$GPRTE,1,1,c,0*07
$GPRMC,183731,A,3907.482,N,12102.436,W,000.0,360.0,080301,015.5,E*67
$GPRMB,A,,,,,,,,,,,,V*71

You'll find a lot of data on the format here - http://www.gpsinformation.org/dale/nmea.htm

I will add that all my experience of GPS is from a marine point of view so its possible some units output other data formats

Pev

Statistics: Posted by Pev — Thu Jul 17, 2008 7:29 pm

GPS for MRC?

2008-07-17T12:17:52+01:00

I think of an Bluetooth GPS paired with RN-1 Bluetooth module,
would that work ?

Statistics: Posted by roboTT — Thu Jul 17, 2008 12:17 pm

GPS for MRC?

2008-07-17T09:35:44+01:00

The ETX/ERX interface on the MR-C3024 is rather limited. It does not use interrupt, has only 2 or 3 bytes of buffer and is often only read every 10mS even when in a tight read loop.

Most RS232 GPS seem to send quite a few characters in their responses. You might try dropping the baud date down to 1200 or less and a tight read loop.

I2c could be an alternative, but I do not know of a low cost I2C GPS.

Statistics: Posted by i-Bot — Thu Jul 17, 2008 9:35 am

GPS for MRC?

2008-07-16T12:37:08+01:00

Guys,

anyone has idea if a rs232 type GPS can be operated by MRC ?

I mean - is there any chance to plug a rs232 device to MRC to read the values ?

If not, is there any GPS module for MRC board?

Statistics: Posted by roboTT — Wed Jul 16, 2008 12:37 pm