Re: [Paparazzi-devel] re:RazzorIMU

[Prof. Dr.-Ing. Heinrich Warmers]

Dear ARCIA ALVAREZ,
one Question, have you resoldered the Resistors from the tiny 2.11?
As for the tworg the 5V analogue inputs  have 2 resistors for a voltage divider.
You have to put away the resistor to grnd to make it possible to measure full 
range 0..3.3V and not 0..5V.
The output amplifier from the sensors can't drive the imput impedance of the 5V 
inputs.
Regards
Heinrich 



GARCIA ALVAREZ, ANA schrieb:

> Dear Dr. Warmers,
> I have finally installed Oliver's software version. I had a compiling
> error related to an AHRS_ALIGNER_led and have solved it after defining
> it in the makefile for my board(tiny v2.11). 
> Now I can see the PFD running, but don't know if it moves in the usual
> way. It has a slow rensponse and a little oscillatory. 
> Ana
>
> -----Original Message-----
> From: GARCIA ALVAREZ, ANA 
> Sent: Thursday, February 10, 2011 10:58
> To: 'Prof. Dr.-Ing. Heinrich Warmers'
> Subject: RE: RazzorIMU
>
> Dear Dr. Warmers,
> I have been looking in this code, although I'll look again. Sorry I'm
> asking too much, but am not very experienced in programming and looking
> into the code is a bit hard for me. 
> Ana
>
> -----Original Message-----
> From: Prof. Dr.-Ing. Heinrich Warmers [mailto:address@hidden 
> Sent: Thursday, February 10, 2011 10:51
> To: GARCIA ALVAREZ, ANA
> Subject: RazzorIMU
>
> Dear ARCIA ALVAREZ,
>
> Please look in the branch
> of oliver and crihstoph
> http://paparazzi.enac.fr/wiki/User:Christoph
>
> Pleas note that Christop has put the imu in the opposideed direction 
> compared to Oliver.
> Olivers code is running on a tiny and chistorp on a tworg.
> Regards Heinrich
>
>
>
> Hi Ana, Hi Felix, Hi Heinrich,
>
> the SENS values in hb_tiny_razor.xml airframe file (4096 = 12 Bit) are 
> only set to reverse the BFP
> formating what ist done for rates in RATES_FLOAT_OF_BFP(gyro_float, 
> imu.gyro); in ahrs_propagate();
>
> /* convert bfp imu data to floating point */
> RATES_FLOAT_OF_BFP(gyro_float, imu.gyro); // olri div by (1<<12)
>
> /* unbias rate measurement */
> RATES_DIFF(ahrs_float.imu_rate, gyro_float, ahrs_impl.gyro_bias);
>
> The trick to get it work is to scale the values from deg/s to RAD/s,
> see the lines below from my ahrs_propagate();.
>
> // scale gyro adc raw to [rad/s] FIXME // olri
> ahrs_float.imu_rate.p /= 61.35f;
> ahrs_float.imu_rate.q /= 57.96f;
> ahrs_float.imu_rate.r /= 60.10f;
>
> The result of the that *must* give closest-by 0.0... rate on silence!
>
> It's at the moment *impossible* to combine these 2 factors,
> becourse the bias is substracted between these to steps.
>
>
>
>
>
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