Re: [Paparazzi-devel] LisaL/Aspirin IMU Issues

[Luke Barnett]

I finally have tracked down the source of the problem. It would seem that periodically the data in the rx buffer gets offset by one, i.e. it starts at accel_rx_buf[2] instead of accel_rx_buf[1].  The strange thing is that this does not occur if I disable the magnetometers and read gyros and accels only. What I did to fix the issue is to call adxl345_clear_rx_buf() at the beginning of adxl_start_reading_data() (both functions are in stm32/mcu_periph/imu_aspirin_arch.c).

With the modified code I have run it for several hours without any issues so it seems to work. I find it a little strange that no-one else has come across this same problem, which makes me worry that there is perhaps something else wrong specific to my hardware?  

Does anyone see any issues with the code changes I made? My experience with embedded programming is limited to say the least, so I'd appreciate it if anyone has any advice on this.

Thanks

Luke

On Thu, Dec 22, 2011 at 11:15 PM, Cédric Marzer <address@hidden> wrote:

It might be a stupid idea and you probably considered that already, but who knows : " the time to failure was shorter each time" = I would check the power supply…

 

De : paparazzi-devel-bounces+spam1=address@hidden [mailto:paparazzi-devel-bounces+spam1=address@hidden] De la part de Luke Barnett
Envoyé : jeudi, 22. décembre 2011 10:31
À : address@hidden
Objet : Re: [Paparazzi-devel] LisaL/Aspirin IMU Issues

 

Hi Heinrich,

 

Thanks for the reply. The motors were not running, the board was actually removed from the quadcopter and sitting on my desk. During the whole time it was not touched or moved so I would expect minimal vibrations during this time. Interestingly, over three successive times, (i unplugged the board for 10 seconds, then powered it up again after each time) the time to failure was shorter each time. This leads me to think it may be a failure related to temperature, however, when looking at it today running the test_imu_aspirin program it read incorrectly from the start. So not really sure what is going on. 

 

Regards

Luke

 

Date: Tue, 20 Dec 2011 14:09:51 +0100
From: "Prof. Dr.-Ing. Heinrich Warmers" <address@hidden>
To: address@hidden
Subject: Re: [Paparazzi-devel] LisaL/Aspirin IMU Issues
Message-ID: <address@hidden>
Content-Type: text/plain; charset="us-ascii"; Format="flowed"

Hello Banett,
some Questions:
Where the motor ruining? Then 5 to 20% full scale vibration is normal.
Is this a temperature problem ? Test it with cooling and hot air.
Sometimes the plastic of the mens  has large humidity and this results
in contact problems by the soldering and destroy the chips.
Regards
Heinrich

Luke Barnett schrieb:

> Hello Everyone,
>
> I'm new to paparazzi and have been trying to get a quadcopter with
> Lisa/L and Aspirin IMU working over the last few months. However, I
> have noticed that after a period of time that I the quadcopter would
> seemingly lose orientation. For example the pfd would suddenly change
> orientation even when the quadrotor was on the ground. Luckily this
> has only happened a few times whilst actually flying.
>
> I have been benchtesting the setup out of the airframe and have been
> able to replicate the issue quite easily by just leaving running on
> the bench. After a period of time (so far between 8 and 14 minutes run
> time) it occurs again and what I have notices is that the raw
> accelerometer readings go haywire around the same time. Prior to this
> everything seems to  be behaving normally. I've attached a screenshot
> of the logs to illustrate what is happening.
>
> Does anyone have any ideas what may be causing this?  Any help would
> be appreciated.
>
> Thanks and Regards
> Luke
>
>
>
> ------------------------------------------------------------------------
>
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>
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