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fergalom
Pulcino
Ireland
15 Posts |
 Posted - 11/03/2011 : 01:19:32
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Have a question. Running LK8000 on PC.
Device A - COM2 - Generic - 9600 - GPS simulated by flywithCE tools
Device B - COM25 - LK8EX1 - 9600 - output from vario / baro sensor.
NMEA checksum disabled
Use baro altitude - on
Here is a sample of the NMEA log
LK8EX1,100938,30.1,-4,99,5.0,*0
$GPRMC,001629.000,A,5306.4814,N,00521.9352,E,8.1,268.0,110311,0.0,E*60
$GPGGA,001629.000,5306.4814,N,00521.9352,E,1,5,0.00,30.0,M,,M,,*7A
LK8EX1,100938,30.2,3,99,5.0,*0
$GPRMC,001630.000,A,5306.4816,N,00521.9314,E,8.1,274.0,110311,0.0,E*65
$GPGGA,001630.000,5306.4816,N,00521.9314,E,1,5,0.00,30.0,M,,M,,*72
LK8EX1,100938,30.2,1,99,5.0,*0
$GPRMC,001631.000,A,5306.4820,N,00521.9277,E,8.1,280.0,110311,0.0,E*6E
$GPGGA,001631.000,5306.4820,N,00521.9277,E,1,5,0.00,30.0,M,,M,,*72
LK8EX1,100936,30.3,10,99,5.0,*0
$GPRMC,001632.000,A,5306.4826,N,00521.9241,E,8.1,286.0,110311,0.0,E*68
$GPGGA,001632.000,5306.4826,N,00521.9241,E,1,5,0.00,30.0,M,,M,,*72
LK8EX1,100935,30.4,10,99,5.0,*0
$GPRMC,001633.000,A,5306.4834,N,00521.9207,E,8.1,292.0,110311,0.0,E*6D
$GPGGA,001633.000,5306.4834,N,00521.9207,E,1,5,0.00,30.0,M,,M,,*72
LK8EX1,100934,30.5,10,99,5.0,*0
$GPRMC,001634.000,A,5306.4845,N,00521.9174,E,8.1,298.0,110311,0.0,E*61
$GPGGA,001634.000,5306.4845,N,00521.9174,E,1,5,0.00,30.0,M,,M,,*74
LK8EX1,100931,30.7,30,99,5.0,*0
$GPRMC,001635.000,A,5306.4857,N,00521.9143,E,8.1,304.0,110311,0.0,E*63
$GPGGA,001635.000,5306.4857,N,00521.9143,E,1,5,0.00,30.0,M,,M,,*72
LK8EX1,100929,30.9,13,99,5.0,*0
$GPRMC,001636.000,A,5306.4872,N,00521.9114,E,8.1,310.0,110311,0.0,E*60
$GPGGA,001636.000,5306.4872,N,00521.9114,E,1,5,0.00,30.0,M,,M,,*74
$GPRMC,001637.000,A,5306.4888,N,00521.9088,E,8.1,316.0,110311,0.0,E*66
$GPGGA,001637.000,5306.4888,N,00521.9088,E,1,5,0.00,30.0,M,,M,,*74
LK8EX1,100928,31.0,12,99,5.0,*0
When I start LK, "Using baro altitude" message displays
However, vario or baro (Hbar) values do not display in LK.
I have tried switching Device A and B - no effect.
Maybe I have missed something in my setup?
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Coolwind
Moderator
Italy
7511 Posts |
Posted - 11/03/2011 : 01:41:58
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You forgot the $ in the LK8 sentence ($LK8EX1 not LK8EX1)
Then the final checksum is wrong.
And I havent checked the rest of sentence syntax.
It will never work like that. |
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katfly
Pulcino
Netherlands
49 Posts |
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bo.
Pterodattilo
723 Posts |
Posted - 06/04/2011 : 23:35:46
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| The resolution is stated to be 0,1 mbar, which corresponds to about 0,8 m if i get this right. I would guess thats not sensitive enough for a vario.. |
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Michal_PG
Pulcino
44 Posts |
Posted - 11/05/2011 : 21:49:09
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MIO400 + baterry pack + micro vario
Yesterday I got the board. I hade to wait for board, components for two months. I hope I will test it next week. (The weather is so good to do something at home.) |
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fré
Pulcino
Belgium
24 Posts |
Posted - 29/05/2011 : 21:25:36
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| Any progress on this interesting topic? |
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rkalman
Falchetto
Hungary
175 Posts |
Posted - 29/05/2011 : 23:49:44
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I'm also prototyping a pressure sensor for lk, almost the same approach, but using MS5801 from Intersema.
Test results about sensitivity and speed are very promising. I can recommend using MS5801 to everybody. |
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peclik
Pulcino
Czech Republic
61 Posts |
Posted - 30/05/2011 : 08:48:50
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Guys, don't you have problems with noise in barometric pressure?
I was trying to make audible vario with BMP085 but the noise was such high that I must use strong filters ending with unusable latency (about 3 seconds).
Maybe there's problem with electronics interference in my setup, I'm not HW pro. |
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Jaros
Pulcino
USA
48 Posts |
Posted - 30/05/2011 : 11:11:05
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quote:
Originally posted by peclik
Guys, don't you have problems with noise in barometric pressure?
I'm working on the same project based on sparkfun boards (atmega + BMP085 + speaker) with NMEA output to mio moov s501.
After few days project is working with basic functionality.
Still working on vario sound, and noise filtering (I used averaging pressure method taken from last 6 samples). It takes about 1 second to update altitude on LK8000 screen. Vario is still a little bit crazy, oscillating between -0.3 to +0.3m/s.
Short output from LK8000's NMEA log
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$GPGSV,3,3,11,04,10,085,14,21,03,279,,15,10,179,*42
$LK8EX1,99378,163,0.0,29,999,*7
$LK8EX1,99380,163,-0.2,29,999,*2F
$LK8EX1,99379,163,0.1,29,999,*7
$LK8EX1,99377,163,0.2,29,999,*A
$GPGSA,A,3,02,05,10,12,25,26,29,51,,,,,2.4,1.1,2.2*3D
$GPRMC,081406.000,A,3605.3011,N,08653.4848,W,0.0,338.9,300511,,,A*7B
$GPGSV,3,1,11,05,77,034,38,29,44,314,36,02,48,064,29,12,26,217,20*7C
$GPGSV,3,2,11,25,31,260,30,26,27,148,27,10,25,046,21,51,,,30*43
$GPGSV,3,3,11,04,10,085,14,21,03,279,,15,10,179,*42
$LK8EX1,99377,163,0.0,29,999,*8
$LK8EX1,99378,163,-0.1,29,999,*2B
$LK8EX1,99378,163,0.0,29,999,*7
$LK8EX1,99377,163,0.1,29,999,*9
-
and some pictures
https://picasaweb.google.com/Jaros.public/FlightComputerProject
Full description, code, and "how to" will be soon on public website (in next few weeks).
Regards
Jarek
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rkalman
Falchetto
Hungary
175 Posts |
Posted - 30/05/2011 : 11:34:52
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Jaros, nice work!
Can lk correctly parse your vario field in LK8EX1? I think you should use integer numbers in cm/s units (-2 instead of -0.2). |
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rkalman
Falchetto
Hungary
175 Posts |
Posted - 30/05/2011 : 11:44:54
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Unfortunatelly I don't have BMP085, but using MS5801 i get the following results,
pressure (field 1) is not filtered, raw data from MS5801 at 10sample/sec (not the full speed of the sensor):
$LK8EX1,99871,121,8,31,999,*1C
$LK8EX1,99876,121,1,31,999,*12
$LK8EX1,99875,121,1,31,999,*11
$LK8EX1,99875,121,-4,31,999,*39
$LK8EX1,99873,121,-8,31,999,*33
$LK8EX1,99871,121,-6,31,999,*3F
$LK8EX1,99870,121,0,31,999,*15
$LK8EX1,99871,121,-4,31,999,*3D
$LK8EX1,99872,121,-3,31,999,*39
$LK8EX1,99879,121,-7,31,999,*36
$LK8EX1,99873,121,-5,31,999,*3E
$LK8EX1,99869,121,0,31,999,*1D
$LK8EX1,99874,121,-4,31,999,*38
$LK8EX1,99874,121,0,31,999,*11
$LK8EX1,99875,121,0,31,999,*10
$LK8EX1,99871,121,4,31,999,*10
$LK8EX1,99874,121,3,31,999,*12
$LK8EX1,99871,121,2,31,999,*16
If you interested in this sensor noise I can share a complete nmea log with you. (approx. 3.5M)
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peclik
Pulcino
Czech Republic
61 Posts |
Posted - 30/05/2011 : 16:45:51
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Thanks, it seems that noise is similar to mine.
I didn't try real flight tests, maybe the sound vario can be useful even with such level of noise. So I'm curious about your results. |
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rkalman
Falchetto
Hungary
175 Posts |
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Jaros
Pulcino
USA
48 Posts |
Posted - 30/05/2011 : 20:11:24
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quote:
Originally posted by rkalman
Jaros, nice work!
Can lk correctly parse your vario field in LK8EX1? I think you should use integer numbers in cm/s units (-2 instead of -0.2).
Yep, you have right. I was doing vario test and left it like that. Vario output is in m/s, but on the end I'll fix it to cm/s.
And about noise, i've seen some good outputs from sensors on the internet using Kalman filter. But to hard to implement for me (I did some programming 12 years ago and now I'm just IT guy ;).
Regards
Jarek
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peclik
Pulcino
Czech Republic
61 Posts |
Posted - 30/05/2011 : 22:02:17
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quote:
i've seen some good outputs from sensors on the internet using Kalman filter.
Yes, Kalman, write some filter for us, please :-)
But AFAIK, Kalman filter will not be so useful for vario. It's strong when combining multiple sources: BARO + GPS alt for example, but GPS alt is unstable and has quite large spread - so I think, it cannot stabilize computed altitude enough with sufficient latency (I'm talking about indication of 0.5-1 m/s in 1-3 seconds after entering lift).
I've used simple low-pass filter together with averaging. And I think it works best.
I know that very simple DIY sound varios with BMP085 are used by paragliders, so it should work, but I have no real-flight experience with it.
Does anybody know what maximum latency between entering lift and generating appropriate sound (or numerical indication of strength) is acceptable? |
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Lk8000 vario input