Replies to This Discussion

Permalink Reply by GillesW on May 29, 2010 at 2:47am

And the associated IMU files :

In main program : "#define PRINT_ANALOGS" = 0 or 1 following expected outputs,

In output file : "#define PRINT_ANALOGS" routines are different.

I know, they are horribly modified !!!
It is not applicative programs, but just working programs to learn to play with the IMU board.



- for AHRS computation : AHRS_V1

- for sensors value visualisation : AHRS_IMU_V1

Regards,
Gilles

Attachments:

• GW_AHRS_V1.zip, 138 KB
• GW_IMU_AHRS_V1.zip, 139 KB

Permalink Reply by Guillaume Helle on June 16, 2010 at 9:55am

Hi Gilles,

how do you connect the LS20031 GPS to the the FTDI basic breakout 3.3V interface ?
Are you using the same the FTDI basic breakout 3.3V interface as the Razor?
Which pin i need connect : 3.3v, Gnd, Rx, Tx ?

Permalink Reply by Harold Jarvie on June 6, 2010 at 7:42pm

How many of you that are using Razors have removed the high pass filters from the gyros.

Any thoughts on how well it works and if you continue using the HP reset after removal?

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Permalink Reply by Guillaume Helle on June 7, 2010 at 1:21am

Hello,

i have not removed the high pass filters from the gyros.
What's the goal of this?

Guillaume

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Permalink Reply by GillesW on June 7, 2010 at 7:34am

Hello,

I have removed them (little bit difficult !) because I don't want them to reject constant moves capture.
Anymay, gyro offsets are not a problem because they are canceled by accelometers & magnetometers data fusion (in the PI loop). So not highpass filters not really useful in my application.
And noise bandwidth is contained by the low pass filters.

But no comparison before and after ...

Gilles

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Permalink Reply by GillesW on June 16, 2010 at 11:25am

Hello Guillaume,

yes, I have used the same interface board, not directly, but using a cable to match the right pins.
I have directly connected GND and Vcc, and I have "cross-connected" Tx(GPS) to Rx (FTDI) and Rx(GPS) to Tx(FTDI).
So , 4 wires to connect, but GND wire to be connected to :
- GND & CTS on the FTDI side
- and to GND pins (4&5) on GPS side.

Best regards,
Gilles

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Permalink Reply by Guillaume Helle on June 17, 2010 at 5:41am

Ok it works fine!

Now my questions ;-)
- Which data are you using : GGA? GGL? RMC?...
- What configuration are you using?

I sent :
- $PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28 for use only GGA and RMC
- $PMTK220,200*2C for update rate to 5Hz (like $PMTK300,200,0,0,0,0*2F)
- $PMTK251,115200*1F for 11520bds

But i suppose there is specific configuration if i want a better position accuracy?

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Permalink Reply by Guillaume Helle on June 17, 2010 at 8:48am

Whith VisualGPS i have only 4m in latitude and 8m in Longitude of position accuracy with 5 satellites...

Attachments:

• VisualGPS1.JPG, 215 KB

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Permalink Reply by GillesW on June 17, 2010 at 12:15pm

Good !

I usually send the following messages (adding CR & LF ):


Port at 38400 Bd :
$PMTK251,38400*27

5 Hz data rate :
$PMTK300,200,0,0,0,0*2F

NMEA messages 1=RMC , 3=GGA , 4=GSA , 5=GSV , 17=ZDA :
$PMTK314,0,1,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0,1,0*28

Funny, we don't have the same data rate message !!!
(and I think I am right ...)

Gilles

PS : ~1 meter with 7 satellites (and a long measurement time) !!!!

Attachments:

• GPS1_3.jpg, 495 KB

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Permalink Reply by Guillaume Helle on June 21, 2010 at 7:22am

So how we can use a GPS if the position accuracy is about 5 to 10 meter in fly?
I had ultrasonic telemeter to my quadrirotor for detect object but if the drone move quickly it is very difficult to avoid crash... ;-)

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Permalink Reply by GillesW on June 21, 2010 at 2:43pm

Guillaume,

Of course 5 to 10 meters ins not enough.
You should have a better accuracy.

Was it outside or inside ?

What I say is about latitude and longitude.
GPS is quite bad for altitude.

The best way is to use pressure sensor (SCP1000, BMP805, ...) for global altitude, and ultrasonic radio-altimeter for kiss landing with few centimeters accuracy !!! (ex : LV-MAXSONAR-EZ0 from MAXBOTIX)

Have a good day,
Gilles

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Permalink Reply by MUHAMMAD T.K.S on February 25, 2013 at 4:06am

Hi

have you worked on Scp1000 D11 or BMP085 sensor? kindly help me out i am trying to run it on arduino

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