Is there documentation somewhere explaining how to use the AHRS Orientation settings? I’m setting up a new vehicle with Navigator controller which is currently orientated 180 degrees out from the usual vehicle Fore/Aft and is also mounted rolled at a 45degree angle towards the Starboard side of the vehicle. Not surprisingly I can’t currently get a sensible compass/gyro calibration. If necessary I will reposition the Navigator but wonder if this is something I can correct in the AHRS Orientation settings? Just don’t understand how to use them correctly and cant find any instructions?
Thanks.
Hi @nemorov,
Yes, in principle this should be possible to correct for using the autopilot’s orientation parameters.
There are some basic instructions and explanations in the ArduCopter docs, but I’m not aware of any really clear ones, which is something I’d like to improve as part of a significant revamp of the ArduSub documentation, and is also something it would be nice to include an intuitive interface for in the BlueOS Vehicle Setup page.
If I’m understanding your description and the angle application order correctly, you’d want a 180° yaw and 45° roll (or possibly a -45° (315°) roll), which there isn’t a default option for, so you’d need to configure it using the custom parameters.
Hi Eliot, Thanks for the quick reply.
If I go into the BlueOS Autopilot Parameters tab I can see the AHRS_ORIENTATION section which is currently showing Roll90. If I click it I get the popup box explaining the Orientation options. I can select any of the presets no problem but if I try to set the custom values by clicking the Custom box I only get an incrementally changeable numerical value but have no idea what this relates to. If I try to enter anything else such as ‘Yaw180Roll45’ it won’t let me. It will only let me type numbers but not the orientation they relate to?? I also get another tick box pop up saying ‘Force’. Not sure what this is relating to?
Any advice on how to enter the custom values would be much appreciated.
Maybe I should be entering these values somewhere else??
Thanks.
The “Custom” checkbox in BlueOS is for manually specifying a value for a parameter, instead of choosing one of the available options, and the “Force” option allows specifying a value that is not within the range of values the parameter is described as supporting. That’s not relevant for your situation.
It’s a little confusing, but in this case there are a couple of available options for the AHRS_ORIENTATION parameter (depending on firmware version) that allow you to indicate that you want to use a non-standard orientation, and then you specify the actual values for that orientation using other corresponding parameters:
Sorry but I must be being stupid here…
I can see custom options in the dropdown box. If I select Custom 1 for example it shows Custom 1 or if I then click the custom tick box it shows 101 and I can adjust that value by 0.01 increments but theres no indication what that is adjusting and I don’t see how this allows me to tell the system that I want to set ‘Roll45/Pit0/Yaw180’.
I can’t see any way to input those values ??
Sorry about this…
G.
Hi @nemorov -
What version of ArduSub are you using?
Assuming you’re on the latest stable (4.5.1), to follow @EliotBR’s advice, you’ll want to select Custom 1 for AHRS_ORIENTATION, and then search Autopilot Parameters for CUST_ROT1_ROLL /PIT /YAW parameters and input them as desired.
Hi Tony,
Yes 4.5.1
Found it now…
Thanks very much for the prompt ( and patient ) support… 
G.
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