AV200 servo gimbal using A2 built in Rx

[jezohare]

Dear Forum / John,

We were using DJI A2 FC built in gimbal stabilization but we could not get it working well, even for still photos.
So we are trying to set up G-lock for single operator 2 axis for primarily stills, our gear :

DIY X8 multirotor
DJI A2 FC using the built in DR16 Rx (with 4 PWM output ports D/F1-4)
Futaba 14sg radio
AV200 2 axis servo gimbal
Radian successfully upgraded to G-lock fw 1.07
Signal Master (to convert Tilt Slew signal from PWM into HSL/SBUS/PPM)

We turned off the A2 built in gimbal stabilization & mapped the F2+F3 ports for tilt and g-lock mode.

We have been trying for several days to configure the SM & G-lock.. so far:

SM recognises the A2’s DR16 Rx PWM input but we cannot set the output properly.

SM software secondary input 1-3 is valid (yellow) but the G-lock software status does not light up green with SBUS/PPM/HSL(Carvec) (not valid/not recognized).

We have wired the G-lock with SM for HSL according to manual.

Are we on the right track wiring like this? (drawing attached below) Or can we wire it differently?

Perhaps use the SM just for converting Tilt Slew (PWM signal) into PPM/SBUS? And wire the G-lock without HSL - plugging the servos directly into the G-lock? If we change the pan to tilt/roll we could fit our wires into the 4 available ports

Or do we have to plug the servos into the SM?

Many thanks, please forgive our newbie confusion :-)

[JohnC]

Hi Jez,

Your wiring looks to be right. These are the stages you would go through to attach the PWM control to the G-Lock using the Signal Master:

1) Check the SM is seeing the PWM inputs properly (you can see them move on the PC display with the sticks)
2) Map the PWM inputs onto the secondary output channels of your choice. Remember you could also connect another Rx to the Signal-Master and mix those signals in too so you can have single- or dual-operator control.
3) Connect the SM Secondary Out (Port 3) to the G-Lock HSL-In (Port-2)
4) Connect the SM Secondary In (Port 4) to the G-Lock HSL-Out (Port-4) (Note you only need the signal wire for this one as power is coming from Port-4)
5) Check the G-Lock is configured for HSL operation (on the Tilt configuration page)
6) Check the Signal Master is lit green on the main PC window (make sure you have selected an axis first so it is getting data)
7) Open the input channel monitor and pick the channels you want for the mode and slew.

I would make sure you have the latest firmware in the G-Lock and especially the Signal-Master (it must be version 0.5)

[jezohare]

Thanks John,

We updated SM FW, G-Lock FW & assistant software.

Attached screenshots below to show our progress.

The HSL 3 active channels were yellow before, but now back to red.

On the G-Lock software the input channel monitor went green & input source Port1 SBUS lit up at last ( but its flickering a bit.. think it could be a wiring problem & will make a better cable)

Unfortunately the Diagnostics window still don't have HSL lit up yet.. mystery.

We’re not sure what to put in the RC Channels box, Slew & mode became ch 2 & 4 after the upgrade, is that the default setting?

We’ve got the standard AV200 Savox servos, according to specs are 250-333hz.

The SM software has choice of 50 & 400hz - is it OK to use 400hz or should we use 50hz or change to FF servos?

The G-lock software has a choice for 400-200-100-50hz - should I put 200hz there for the Savox servos?

Many thanks again, Jez

[JohnC]

Jez : You need to assing the two PWM inputs to be the 1st choice for the secondary outputs 1 + 2 (ie you are mapping those inputs to the secondary output).

It doesn't explain why the HSL status did not go green though : Are you sure you have it connected to Port#2 of the G-Lock ?.

I will set a rig up the same in the morning and double check nothing has gone amiss with the new firmware.

JohnC

[JohnC]

Jez: I have found the issue - the G-Lock HSL message was changed a bit for firmware 1.07 onwards and version 0.5 of the signal master does not recognise it.

I uploaded version 0.6 for the signal master which is needed for G-Lock 1.07 onwards. It is in the signal-master forum.

This should get the comms with the G-Lock back online : let us know if the PWM is working OK with it.

JohnC

[JohnC]

Jez: on your other questions:

The HSL channel selection is shared with the 'Port#1' channel selection - so choose your mode + slew from the input channel monitor and select them for Port#1. It will then use them from the HSL because the Port#1 input is not valid.

For the servo speed, set it as 400Hz on the signal master. The Savox should be fine at 400Hz.

The G-Lock setting is just for servo pulses generated by the G-Lock module. If you are using a camera trigger, set it to 50Hz so as not to confuse the trigger device.

JohnC

[jezohare]

Thank you very much for your great support John,

Because we got bit impatient with HSL not working, after a few hours of no progress (and not read your last 2 posts yet!), we re-wired SM & GL  differently using the SM just to convert PWM to SBUS, and then "played around with the SM software" until we got it working, perhaps not entirely correct yet - using 2 channels for one function it seems.. but that was the only way we could work it out.

So our gimbal / glock / SM seems to be working OK now, with SBUS lit up green, yes it needs serious tuning.. bit jittery sometimes, perhaps too high gain or something else.. wondering if we should just try to tune it like this first, save the config, and then update SM FW and try HSL way again..

Will it be any better using HSL compared to SBUS?

We are just so thrilled we could finally get both axis stabilization and tilt working roughly!!

Can share our 'SBUS' connection diagram later if you're interested to see it / you think we should show it.

Again many thanks for your help!!

[JohnC]

Hi Jez,

I assume you set the Signal-Master to output SBUS instead of HSL then connected it into Port#1 like a regular SBUS Rx ?. There's no problem doing this - but it is just one-way traffic and I expect you had to plug the servos directly into the G-Lock ?.

With the fix you will be able to plug them in to the Signal-Master so you only run the 4 wires down to the camera tray.

The HSL does run faster than SBUS - but I doubt you will notice any difference in response to stick movements.

Check out the other thread on tuning : it has some tips on using the graph and remote gain. Using a dial is quite convenient. One possibility you have is to plug another Rx into the Signal-Master and just map the rotary dial into the HSL message so you are combining the PWM with another Rx just for tuning. The Signal-Master is a very flexible module for things like this.

Sorry for the inconvenience with this : the HSL change mainly affected the BLD modules and they were thoroughly tested but the fact that the Signal-Master also needs the same message was missed.

[jezohare]

OK thanks again John,

Just tried tuning it a bit more & already feels much better than Rx's built in stabilization.. OK for stills which is our primary need now.. Obviously will try some video too soon.

I'll check the other threads and try tuning with tuning graph etc tomorrow. May keep it sbus for now & save the configs, then try HSL wiring again after that. Cheers! Jez

[jezohare]

Hello John, sorry I don't reply all your questions yesterday..

Yes we connected to Port #1 with SBUS & connected servos to Glock.

You said SBUS not as fast as HSL and only one way traffic..

Does that mean that with SBUS comms the stabilization will not be as responsive & more lag than with HSL? If thats the case I will try HSL.

I have tried tuning more this morning, still trying to understand the graph and have not made remote gain on my tx yet.. but I'll give it a try later. I only have one radio so I dunno if I can put another tx. Even with my FC I decided not to use remote gain & do all the adjustments on the ground between flights. Is that also OK or do we really need to set up remote gain on tx?

One thing I'm trying hard to get sorted first is make the gimbal able to tilt from horizontal to vertical and still get stabilization at both extremes.. I have slewing angle max at -120 any more and it goes haywire a bit sometimes. The tilt gain seems best at 36 and no more.. but roll gain I put up to 180 and OK. Is that the case? Tilt only little gain so no jitters, and roll put it up a lot so stabilize is better?

If I am at horizontal its still stabilizing, but when its pointing vertical down there seems a limit at 90 degrees and I cannot get it to stabilize the tilt past vertical, its locked. What is the box for that? - I tried almost everything it seems and no luck yet.

I also tried proportional slew.. is proportional mode more for shooting stills single op? and the other slew for shooting video / dual op?

Many thanks if you have time to answer.. sorry for so many questions :-)

[JohnC]

Hi Jez,

The SBUS is only for RC commands : it does not affect the actual stabilisation at all. However I would go back to the HSL just for the convenience of connecting the servos at the signal master.

For the remote gain, I just mean for the initial tuning. It is just easier than typing in the gain each time - but it's not essential. I didn't mean to leave it all hooked up for flying.

If you want to slew it past -90 degrees, you need to change the min angle for tilt to -110 or whatever. However if you slew it down to -90 degrees tilt, it will stabilise at that angle as you move the gimbal : it should not 'lock' at any point for the stabilisation - only the slewing.

The gain seems a bit low for the tilt - but every gimbal is different with servos/gearing etc so maybe it is the case.

Often people use proportional-slew for single person operation then switch to spring-stick for when a cameraman is operating the gimbal. spring-stick gives smoother control and is better for video whereas the proportional mode is good for single-op stills shooting.

JohnC

[jezohare]

Many thanks again John,

I see what you mean - if I revert to HSL theres considerable less wires going down, SM and servo wires etc can be on top of gimbal.

Thanks for explaining the proportional slew, I'll use that now.

I will try the vertical stabilization tuning again now. What I need is just horizontal to vertical (not past vertical) but the stabilization must be able to go past vertical if you see what I mean.

I'll let you know how I get on with your last tips.. thanks again!

[jezohare]

Dear John,

We updated the SM to 1.06 and re-wired the HSL way, reduced a few wires and looking more tidy now.

We can't get the proportional slew working in this HSL way, also can't get stabilization of vertical position past vertical.

Will keep messing around with everything to try and sort it out..

Attach screen shot of glock setting.



And here's our SM settings:

[JohnC]

Hi Jez,

I'll check the proportional mode operation : I'm not sure if anyone else has used your combination yet.

For the stabilisation, it should allow you to slew down to the vertical and it will stop there - but it should not have any restrictions on the stabilisation (ie if you are at -90 degree tilt then you lift the aircraft nose-up, the stabilisation should take it past the -90 degree point in order to keep it vertical.

Are you seeing this ?.

Edit: Jez, I just checked your picture and it has the servo output at >100% : it should be spinning like crazy !. It seems the problem is that you have standard servos with the pots inside right ?. The G-Lock needs continuous rotation servos with fixed pots.

This is the kind of thing I am talking about : Continuous Servo Rotation Mod 

[jezohare]

Thanks John,

Yes I have Savox servos that came with the AV200 gimbal.

I also have 2 nice Freefly servos that I bought with the used radian. The connectors are not compatible the pots on the AV200 so I have not installed them yet.. besides I have little experience installing servos with potentiometers. (I can read the manual again)

Would the FF servos be any better / do they need the mod you shared?

Or should I mod the Savox servos? 

BTW just flew the gimbal & shot video with D800 & 17-35mm on 17mm.. to my surprise it was remarkably steady with rough tuning. 

There was some servo lag when I moved around fast on purpose, but when I hovered or smooth tracking it seemed perfectly OK. Was in atti mode and was moving around in the breeze very smooth.