GT3B Hack Question and Answer Thread
 

Post your questions! I enjoy answering them. Any question concerning the gt3b, even if your just curious.


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Alright well a genius over on RCTech (psx) developed a new firmware. Now the Flysky GT3B can have 6 channels, 3 pos switches, 4ws mixing, and dual esc mixing. So i developed a kit which will include everything required to install this firmware and any future updates. This kit is can now be ordered here.

I'll be posting up some vids and such hopefully tomorrow of it in action, along with further details how its functionality. As you guys start hacking your GT3B feel free to post up questions if you get stuck.

"thumbsup"


List of features, updated

i belive this is all the new features the firmware offers in addition to the ones already there.

- ~15 model memory depending how many channels your firmware is
- Sub trims
- More trim value (from 30 to 99)
- copy models
- fixed expo
- Model reset
- Steering speed
- 4WS Mixing
- Dual ESC Mixing
- Dual ESC steering
- Multi Positions Switches (Up to 8 True positions out of a single push button)
- Key Mapping (any key can control any channel in many different ways)
- Calibration Menu
- Key Test Menu
- Backlight on time
- Inactivity Alarm
- Adjustable Low volatge warning
- Adjustable Maximum End Points (Up to 200% i think
- Adjustable dead zone for steering and throttle
- Turn keep beeps on/off
- Adjustable long press delay


The Trim and d/r keys can do this

- nothing, it is possible to assign each button individually as key
- trim of channel 1/2
- dualrate of steering/forward/back
- expo of steering/forward/back
- change channel "n" value in range -100...100
- subtrim of channel "n"
- 4 wheel steering mix -100...100%
- DIG throttle mix -100...100%
- Multi-POsition, switches position up/down
- steering speed turn 1...100%
- steering speed return 1...100%

They Can be setup to act like this

- momentary, hold left/right trim key to get end values,
when nothing pressed, servo is at centre
- no long keys, long press is the same as short press
- autorepeat is on
- long press of one of trim keys will reset to
centre/reset value
- long press of trim key will set to coresponding end value

And they can have an adjustable step rate, oppisite click reset, reversed, etc.

And the Keys (ch 3 button, back button, end button, and the trims if set individually)

- nothing
- switch channel "n" value from one end value to opposite end
value.
- reset value of channel "n" to centre
- switch crab (CRB) no-crab (NOC) for 4 wheel steering
- switch DIG mix between -100 and 100 (more useable when using
return to previous val key setting)
- Multi-POsition, switches position up (at END back to 1.)
- Multi-Position Reset, switches position to first one

Reserved for important links


Firmware archive, click here



HACKS

Raise switches for easier control

Video on how to hack



FAQ

Where do i find the 8ch and 6ch rx's
What Rx's work with the GT3B

How do i calibrate my GT3B

How do i Bind a 3CH rx to the radio

How do I BIND a 6CH rx to the radio?

Trouble Shooting

I broke my programmer in two, it still won't read swim

I can't figure out how to setup dual esc

I keep getting a error message "STVP GUI has quit working"

I broke the antenna cable off the board"

Templates

Dual ESC Mixing template for firmware 0.6.1

Setup for 4WS and Dual Winches on scaler (0.4.1)

Template/HOW-TO setup Dual ESC 0.4.1

saved

Great now I gotta get one of these radios!... Lolz

Alright her's some proof it works...excuse my messy work bench

http://www.youtube.com/watch?v=v7dGifwCvtw

So i pulled the steering wheel off my gt3b today, and i think i can get some push buttons in there to get the st a th trim buttons more accessible while driving. Which will help if using the 6 ch firmware. So i'm gonna add this to my todo list, hopefully i'll get to it in the next few weeks.

Also this radio is quite heavy compared to speky's and the ones i build. Mostly because there's a glass brick up top that i believe is the back light, and it uses 8 AA's. So i'm gonna look into modding it for Less voltage, or possibly a 1 cell lipo mod with a step up regulator...I'll also look into the backlight on this guy, i may be able to get ditch the glass/led setup and put in a good Electroluminescent backlight.

Good work, I'll be modifying mine on my next paycheck and post some pics. I have one of mine running on a 3S lipo (makes it much lighter). I Haven't pulled the data sheet on the voltage regulator yet which is something I need to do. EL back lighting would be a great for viewing the screen in daylight. I need to get off my lazy ass and start tearing into my spare TX to see what's possible.

Ok so the backlight can be replaced with an el. I'm looking into parts for it, i'll probably have some custom cut foam pads and el panels made up once i get this hack kit stocked up good and selling good...as i'll have to buy 100"s of el's and foam pads to be a drop in replacement...with a few solder joints, maybe.

I see you got the mixing down. You mentioned 3 pos switches. How many can u add and can you show us how & where? I have a scaler that I will need 4 channels for accessories. And I'm thinking this radio will fit the bill.

Posted on a POS smartphone :p

You can map the aux channels to use the 3 position switches already there...ch 3 trim, d/r and the st and th buttons can act as 3 position control.

If anyone wants to venture off and try better back lighting on their own, smartieparts.com sells a good el driver, however you'll need to find a el to suit the size of the gt3b

Are they only momentary? I need something for my shafty dig. It has to stay in pos.

Posted on a POS smartphone :p

No, it can also be setup like dx3e. So a click will change position. Momentary gives you endpoints when switch/button depressed, when let off it returns to center pos

I would assume you could piggyback a spdt switch onto the factory momentary like we did on the original dx3 radios?


Posted on a POS smartphone :p

probably...its also probably possible that you can hook up a spdt center off switch with a few resistors to the ch 3 button and have a 3 position switch that way as well

what do i have to do to get this radio to safely run off 2s lipos?

i know you have posted a list of compatible receivers but i have a hand full of the hobby king 6 ch receivers already they look identical to the 6ch one you linked to but they are the v1 model from hobbyking. will they work too? if so im ordering 2 radios asap!

has to be v2

will the 3 ch receivers work with a radio flashed for 6ch?

I don't see why not, ill try it though tomorrow when I get back home

K thx. Gonna order a pair of radios. Can u set me up with a mod kit with parts for 2 radios ?

Posted on a POS smartphone :p

Send me a pm

did you ever check to see if a 3ch receiver will work with a 6ch flashed radio?

Yes it works just fine

So there is a small bug for unexpected use. But it should be fixed soon

Anyways what i figured out when using two buttons to do the same function problems can accure if one of the switches is set to momentary.

So i had the d/r set to end, which allows step rate and long press will go to endpoints. and i had the ch 3 trim set as mom (momentary) Which goes to enpoints when pressed and returns to center when let off.

Now the bug is the mom center will overide what the d/r changes the value to, so if you click d/r 3 times up w/ a 10% step rate, you will have a 30% servo throw or mix for a few seconds (like 10) then the mom function will overide it back to zero.

But i guess when he designed this firmware this was unexpected use, so its not a bug because it was programmed this way, however its on the todo to be implemented in the future.

So for now can't have mom and the other functions set for the same ch/mix. But can still set one switch for a 100% step rate for instant dig, will act much like the dx3e 3 pos switch. and set another switch for a smaller step rate.

Or use one switch and just hold the switch for 1 second or longer to activate dig.

Hmm interesting. other than the screen any advantages to a HK-T6A ?
How does the radio feel in hand compared to the tried and true TQ radios?

Ill have to look for some more info about this radio. Very cool that it uses the same RX's as the HK-T6A I have a handful of the 3ch and 6ch RXs

seems like the way to go it you dont want to mod a pistol case and want a screen.

Must be the v2 rx's

The handle is a bit big for my hands (fairly small) which is strange since the chinese designed it, you think it be for small hands. and the dual esc functions will be great, for my liking, once the bug/limited functionality i posted earlier is fixed. beings i go in and out of dig so many times most the time you can't even tell, as its just to load/unload suspension, But it works great now considering the price tag and most buyers of a budget radio probably arn't pro's


If this was around before i started looking into custom radios, i would have never built mine...and if it wasn't for the radio i'm working on now i may have customized a gt3b for my hand and used it as my daily tx...but i'm slowly getting parts together for my next "personal build" which will kill any conversion done before, including the 6i conversions.

Now if you need 6 channels, with dual esc and 4ws mixing i would suggest this radio over the t6 conversions as its much cheaper and i still haven't found a good way to do either dual esc or 4ws mixing so its easily adjustable for someone besides me. And for the custom people the gt3b could be a good builder, there is room in the st wheel area for switches/buttons. Plenty of room in handle, switches can easily be moved around.

I've been considering cutting the batt tray off, put a 1 cell lipo and dc step up regulator in the handle, and shrinking the handle down a touch, make the ch 3 button work for my hands better, move the st and th trims into the st wheel column, move the rotary encoded somewhere for quicker programming. El backlight, frsky module, etc...There really is alot of stuff that can be done, and its a 35 dollar radio, so if you mess it up its not a very expensive mess up.

I hope someday we will be able to program it and simulate the channels on a pc. The 9x custom firmware has it (eepe) so it might be possible with the 3b radio. But the 9x uses a atmel atmega, and the gt3b uses a stmicroelectronics stm8s. psx over on rct told me he isn't a app developer for the pc so he probably won't be able to do much for this service, but i'm looking into getting some adobe software which i believe will design apps for pc's if so i'll look either make a simple firmware generator, you select the firmware you wish to use, then adjust your models, then save it and flash it through the stm8s programmer. Or i'll see if i can use the programmer and DSC port to create a full on simulator/programmer/adjustment settings like t6 config (But much better, like digtal radio) But this all depends if i have the knowledge on how to build it, in other words if a high dollar adobe suite can step me though it.

here is a thought I wonder if the ST and TH trim push buttons can be programed to move a servo faster or slower with each press.

for example when using a servo winch. press > to winch out slow >> to winch out faster >>> full speed. pressing < steps down to the next slowest until you reverse and then steps up in reverse speed from there

Thats a linear output. I believe it will work. I havent got my radios yet so im not 100%

Posted on a POS smartphone :p

never mind just read the other thread and it seems you can

Got my radios. They are super smooth compared to my losi dsm radios. Gotta wait for the programmer to get here so I'm getting used to the feel of it with my jet boat! So far it handles awesome.

Posted on a POS smartphone :p

Hay losikid what's the major difference between the v1 and v2 hobbyking 6ch receivers? Is it just a firmware update? Does anyone update these? Is there any way to get the v1s to work with this radio?

Posted on a POS smartphone :p

V1's use a satellite. V2's have a red thing on the antenna

Simple answer is no, can't make them work together...but it is possible to use a v1 module however the amount of time and money you waist trying to get the v1 module to work you'd just be better off buying v2 rx's because v1's are disappearing and more expensive, and the v2's are better

Losikid, do you know if the 3ch rx's will handle a 2s/7.4v? I know its rated 4.8-6v but curious how much it can handle.

I can answer that. No it will not be able to hold 2s 7.4 volts. Reason I know is because my buddy thought he would one up me with my BEC. He went directly from the battery deans to jst connector, he had super awesome steering for about 30 secs that's when the magic smoke :twisted: appeared out of the receiver. It also fed 7.2 volts to his new Novak 3s and fried that also.

Losikid,have you tried the new version 3 firmware? Looks promising "thumbsup"
Now I have fellow co workers going out and buying these radio's since the firmware upgrade is available.. :mrgreen:

Glad I read this before i fried something. I have some of the 3ch RX's that Ive only bench tested with a 2s and my T6A and they worked.

I think what it was, is under load and with the speed control running the VR just could not take it. It only failed after running it up our rock climb. Also note the BEC in the speed control was disconnected at the time of smoke show.

So what all have you tested on this setup so far? Just the dual mixing esc?

Ive owned my GT3B since its release from FlySky in china (friend sent me it from china) And used on my cars I race at local track and have had great reviews about it. I actually quit using DSM @ the track over this radio.

Im looking at using it for my class 3 scaler for 4ws and my winch using your setup. Hows that looking ?

I'm on my phone, so can't go into depth, but yes it'll work a winch and 4ws just fine