For discussion on any the supported hardware platforms, such as TauLabs, Quantec, OpenPilot or the STMicro Discovery platforms.
no avatar
User

hank.su1968

Posts

57

Joined

Sun Jan 10, 2016 4:57 pm

MS5611 Pressure Barometric sensor

by hank.su1968 » Mon Jan 11, 2016 1:31 am

Hello folks and flight mentors:

Could I ask a small question about MS5611 baro sensor? I purchased a sparky 1 flight board with MS5611 baro sensor mounted.

Do I have to do baro sensor calibration before pre-flight check for altitude-hold compensation? I have checked the MS5611

specification datasheet but there is only mentioned 6 coefficient number loaded on chipset, factory calibration,..etc.

Can anyone mentor help point out how to do baro sensor calibration in Taulab GCS?


Thanks in advance....
User avatar
User

peabody124

Posts

1339

Joined

Tue Feb 18, 2014 12:33 pm

Re: MS5611 Pressure Barometric sensor

by peabody124 » Mon Jan 11, 2016 4:08 am

What are you trying to achieve? I've personally never had the need for further baro calibration.
no avatar
User

hank.su1968

Posts

57

Joined

Sun Jan 10, 2016 4:57 pm

Re: MS5611 Pressure Barometric sensor

by hank.su1968 » Mon Jan 11, 2016 5:12 am

Dear Master peabody:

I would like to achieve AH altitude hold or further PH. I used to test my QAV 330 with OP Revo when I set AH, sometimes I will

get the large oscillation caused my quad crashed. I have completed tons of gyro, acc, and board level calibration, etc.... The only

thing I didn't attend to do is temperature calibration, so I guess thermal issue could be the black box I miss. Is there any code in

the firmware for applying compensation to reach accurate in altitude hold.


Thanks in advance.
no avatar
User

icee

Posts

216

Joined

Thu Apr 02, 2015 8:00 pm

Re: MS5611 Pressure Barometric sensor

by icee » Mon Jan 11, 2016 5:35 am

Do you have open cell foam over the baro as suggested?
no avatar
User

hank.su1968

Posts

57

Joined

Sun Jan 10, 2016 4:57 pm

Re: MS5611 Pressure Barometric sensor

by hank.su1968 » Mon Jan 11, 2016 6:29 am

Hello:

I purchased from 2'nd market, and someone had already put a foam on it. The outside box was brown to eliminate light -

thermal effect. The OP revolution has temperature calibration selection for performance improvement in sensor calibration items

because I am new in Sparky. Is there a same selection in configuration setup?



thanks.
no avatar
User

icee

Posts

216

Joined

Thu Apr 02, 2015 8:00 pm

Re: MS5611 Pressure Barometric sensor

by icee » Mon Jan 11, 2016 6:55 am

The MS5611 has onboard factory calibration of tempco that we just use.

If you're getting oscillation you may want to turn down the altitude gains-- e.g. lower AltitudeHoldSettings.VelocityKp and velocityKi to both be .15
no avatar
User

icee

Posts

216

Joined

Thu Apr 02, 2015 8:00 pm

Re: MS5611 Pressure Barometric sensor

by icee » Mon Jan 11, 2016 6:57 am

Just to note, two things:

1) Some manufacturers of clones have done bad things with voltage regulation for baros. if you see huge swings in altitude sitting on the bench in the scopes view in GCS, you have a problem.

2) Calibration is something that may help with absolute sensor precision. But the sensor is already zeroed at power-on and the current value is taken as a target when you enable althold. So even if the sensor is off by 100' it doesn't really matter. And temperature changes, etc, are not rapid enough to cause huge swings in altitude.
no avatar
User

hank.su1968

Posts

57

Joined

Sun Jan 10, 2016 4:57 pm

Re: MS5611 Pressure Barometric sensor

by hank.su1968 » Mon Jan 11, 2016 7:09 am

Hello mentor:

Thanks for you answer. I will keep in mind....
no avatar
User

Therflub

Posts

10

Joined

Tue Mar 22, 2016 9:33 pm

Location

Russia

MS5611 Pressure Barometric sensor

by Therflub » Mon Mar 28, 2016 1:34 pm

You could use a scale component with the following parameters :

A1 = your mV input from the Volt output of the C1p26 MFin input
A5 = 1000
A2 = 6000
A4 = 0
A3 = 400
X1 = your pressure output in bar

Sam
no avatar
User

hank.su1968

Posts

57

Joined

Sun Jan 10, 2016 4:57 pm

Re: MS5611 Pressure Barometric sensor

by hank.su1968 » Tue Mar 29, 2016 1:17 am

Thanks for you answer. I will keep in mind and try..................................
Next

Who is online

Users browsing this forum: No registered users and 1 guest

Powered by phpBB ® | phpBB3 Style by KomiDesign
cron