Dynon Data Log

[lolachampcar]

I see the NEMA messages in the Dynon Data Log and would like to write a parser for the EMS channels to keep from having to hand record performance data during Phase I testing. There really is no convenient way to install a serial data recorder and writing a binary log parser would be much easier. By chance can you share the record structure for the EMS data?

Thank You,
Bill Hart

 

[Brantel]

The serial streaming log format is the way to go. Its detailed in the install manual starting on page 19-1.

 

[dynonsupport]

Bill,
The format of the Dynon system log is not something we are willing to document. It's an internal format that is constantly in flux.

User Datalogging is something that is very high on our list and is likely something that will be in the next 1-2 releases of software. Until then, you'll need to use the serial port.

 

[lolachampcar]

Come'on guys.....  Just tell me where the EMS data is (even if in raw format) for the current release of software and I can write a quick parser to get what I need.  Even better, let me borrow your parser (under NDA?).  If not, I'm going to end up buying one of these $250 RS-232 to SD card boxes as tacking a 232 receiver onto one of my SD equipped Freescale designs is just not time efficient.  I'd much prefer to give Dynon the money and not mess with the hardware.  The only other option is to throw a pot on each input of interest (or take a heat gun to the TC of interest) and move one input at a time to try and figure it out.

I understand the reluctance but my Phase I stuff will be done by the time your logging is tested and released.

Please        You guys know what it is like when the obvious solution is right in front of you and your facing taking the long way.........

 

[lolachampcar]

at $60 this is the best hardware solution I've found-
http://www.robotshop.com/PDF/Logomatic-v2.pdf

 

[Brantel]

I built an Arduino based SD serial logger for like $50.00.

No reason to beg Dynon.

Just use the serial port and log your data real time with an easy to make logger or a laptop.

 

[lolachampcar]

Do you remember off hand what the data string rate was?  I've checked appendix 19 and they only mention output rate for the NEMA stuff (at 1 Hz I think).

Brantel,
I am glad laptops work for you.  They do not for me (see first post).  Yes, a logger is an option but it is still easier to parse an existing log file versus recreating the wheel.  If it takes a please to get access to the data format then I have absolutely no problem with using good manners. 

Lastly, Arduino, I've heard of people playing with those pre-made boards.  They appear to do a good job of making micros available to the masses.  I am glad it worked for you.

 

[dynonsupport]

You choose the baud rate, and we saturate whatever speed you choose.

 

[lolachampcar]

Thank you.

 

[lolachampcar]

ok, a SparkFun serial logger and a bunch of Vc code later and now I am looking at data.  It would appear as though GPS data is used when generating Wind Speed and Wind Direction yet ground speed is only available via NEMA messages.  If I read the manual correctly, I can not get AHARS, EMS and NEMA in the same data packet.  Would it be possible to add ground speed on the next release (to the AHARS data set I assume) as combining it with TAS is helpful in evaluating Pitot and Static performance?

BTW, gaining speed over the runway and logging P Alt is a wonderful way to check your static system.

 

[lolachampcar]

The EMS data set lists TC1-TC14. I can tell CHT from EGT but is there a pin mapping for TC1-TC14 so that I can tell the cylinder?

 

[dynonsupport]

There is not. Since a user can hook up 14 J types, 14 K types, or any mix on any of the pins, there is no way to know if all you have is the datalog because we couldn't afford the bandwith of transmitting the configuration constantly. You need to get the config file for the plane so you can see what was on which pin.

 

[lolachampcar]

Sorry for being so dense, but can you tell me which two EMS connector pins TC1 is connected to (and TC2,,,)? I would not expect Dynon to know how I used those TC inputs but I do need to know which physical pins on the EMS connector are mapped to which TCxs in the data.

Also, any chance of getting GS added to the AHARs data? It would help in setting up the static system as AHARs plus NEMA is not an option.

 

[dynonsupport]

Page 19-9 (where the serial format is documented) covers this directly.

I doubt we'll be folding GS into the serial stream anytime soon based on resources, and how may people appear to be using it. But you can back-calculate GS from the wind speed, wind dir, TAS and compass we do publish.

 

[lolachampcar]

duh! Thanks for pointing out the obvious. Glad it was not a rattlesnake.