FlySky GT3b Hack Tech Thread
 

Many of you probably don't know about all these amazing mods we are doing in the FS-GT3B Thread. Probably because its so LONG, and you don't hear about any of it till page 100. So here's a thread dedicated to all the tech of the mods. Feel free to ask questions as well.

Alright so here's the story, to sum up how this all came about.

Most of this all started when a local RCT member, PSX, decided to take the leap and popped open the gt3b. Originally he simply took the original FW on the GT3B, decoded it and modified it to fix the issues. Lack of trim, expo, etc. But he continued his quest for a better radio and developed his own firmware. Currently this firmware supports a alot of new features....now many other users, including myself, are working on ways to make the radio better.

There are also alot more mods, and services offered for the GT3B, which i'll be posting them in the next few posts. However i do have a small website which i was selling electronics for RC Rock Crawlers, due to my push for a very advance crawling features out of the GT3B, i have taken it under my wing, to make it easy for everyone to have a affordable radio. I sell firmware hack kits, pre-hacked gt3b's, here soon hack kits for all the mods, and easy to understand instructions and tutorials. Most of this is found at www.overkillrc.com . Most of my tutorials are forum posts scattered around over on RCC, but soon will be pdf's available on my website.

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

- 3-8 channels
- ~15 model memory depending how many channels your firmware is
- Sub trims
- More trim value (up to 99)
- copy models
- fixed expo
- Model reset
- Channel 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, opposite 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

Overkill RC links
 

Overkillrc offers alot of stuff for the gt3b. Such as DIY hack kits, pre hacked GT3B's, and more. Please follow this link to see all the products

http://www.overkillrc.com/products.h...=0&sort=normal

OverkillRC's FW Kit Install guide

OverkillRC's Firmware Archive (of all past and current FW's)

Important links for this thread
 

As important tech is posted, i'll update this post with a link.

FS-GT3B thread links, thanks to Quang Voung
 

Here is the links QuangVuong has assembled on page 100 of the FS-GT3B thread

Here is some of the stuff i've posted over on RCC to get people started

_____

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?

Template/HOW-TO setup Dual ESC

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"

Great work on the mods folks

Just wondering if you have considered approaching the manufacturer and if so were they interested at all in offering a fully featured / modded radio for sale ?

Cheers

How does the - Inactivity Alarm Work? i got a Buddy that uses this radio and he seams to leave it on all the DANG time! LOL

No i don't think we have...but FLYSKY won't offer such options, they don't even fix their own firmware for well known bugs (expo)


It starts beeping after no input for a settable amount of time

so what are the ups and downs of this radio is it worth it or should i just save a little extra and get a used futaba

$35 Radio and receiver...2.4ghz. $8 for extra receiver. You cannot even buy one Futaba receiver for that price...(p.s...I ran Futaba for almost 20 years, it is not 4PK, but again...$35 USD).

Overall...for club race, using on car, it is the best thing that you can get for $35. But if you are planning to use it for National or higher competitive level...get FUTABA.

well i am just getting back into rc after like a long time out and i do plan on racing but i doubt it will be serious for a little while till i get everything back up too par and such...i have been contemplating this radio for quite sometime. so is the radio still decent without the hacks and upgrades or should i shell out the 70 bucks and get it upgraded. and where is the best place to buy it from...

Its decent not hacked, but expo don't work and a very limited trim.

The new firmware improves by a ton.

If you want to hack it yourself, Hobbypartz sells it the cheapest, but now you have to have $50 min order before free ship so you need to throw in some lipos or extra rx's.

If you don't want to hack it yourself, overkillrc.com would be the best place to get it. I sell them pre-hacked. And their brand new. All i do is take it out of the box, pop the top off, program it, cut the slot so it can easily be updated, power it up, calibrate it, and put it back in the box. I sell those at $70 + ship. It includes the programmer and equipment to update the firmware if you ever wish to.

ok so say i get it through you and it doesnt work is there some kind of guarantee for it.....

Yea if its DOA i'll replace it. But i do turn it on, calibrate the st, th. and check all the buttons. So theres no reason it shouldn't work, unless its damaged in shipping. If it is damaged in shipping i only send radios via insured mail so it'll be covered by usps.

Can we have this thread clear of questions about the radio please? not being funny but this is supposed to be a thread posting completed modifications for the radio, not questions about how it is in stock form. use the Flysky GT3b Transmitter thread here http://www.rctech.net/forum/radio-el...ansmitter.html

we don't want the useful information in this thread cluttered up with and lost within questions from people too lazy to use the uberthread which contains the answer to every possible question you could ever have and some that you would never have, at least three times.

Mods done but I fuc#€d up with antenna.. How I resolder it. Radio works fine but distance is only like 100ft or 30meters. I have read thats is almost impossible to fix but I like to try

anyone having issues with the manuals? I just purchused the firmware from overkill but the links for the install and how to program are not working.

If anyone has a good version can the PM me it!

Hopefully this firmware will fix my expo issues. My M05 turns WAY too quick. Im new to RC and always thought I just sucked but some other guys I know tried it and were like HOLY Sh!t it turns fast. Also I am noticing an issue with the steering not centering perfect after a left turn. hopefully its not my brand new savox servo.

Thanks

Jay

Jay, add .webs between overkill and .com in the URL, this made the links work for me. I think he is fixing the site soon.

LosiKid I just ordered the programming kit, voltage regulator and steering bearing from your site. Can you give me some specs on the regulator? How much or how little input voltage I can use?

i got my beemerfan modded radio back today, what a difference. :nod:

6.5 volts up to alot, so a 2s or 3s lipo is ideal

Sorry for the delay, i guess i stopped getting email notifications for this thread

Site not working for me. Homepage loads but all the links are dead. I cant buy your stuff if website no worky!! lol I'll keep checkin.

click on the products tab up top first to get to the store

other links, add a .webs between overkillrc and .com

Everything I click on the website was working for me a few days ago when I checked last. I assume you fixed it and I thank you, it is much easier to navigate now.

Got the upgrades installed and tested and I must say I am impressed. The radio tuned my cars with ease and precision comparable to any high $$$$ radios I have used. I will be highly recommending this to fellow racers and forum members.

Only issue was my dadgum antenna wire. I read a few posts here about it and it was clearly stated in the instructions to be careful. Well, I was very careful and the first time I looked at it funny it popped off anyways. I seriously have no doubt it would have broken soon had I never even opened the radio in the first place, so here is hopeing I just got a fluke defect and this is not something everyone opening the case will have to deal with. Luckily I have over 20 years experience soldering and I was somehow able to reconnect the coax cable to the itsy-bitsy dots on the board, went out and tested the range and it was at least as good as it was new. :sweat:

Anyways thanks so much for putting this all together in easy to aquire kits and all the information along with it. Also thanks to PSX for your hard work too, I really appreciate you guys.

Hey Maple, I just picked up a hack kit. If you just want to update your radio I can help you out. You'll just need to get yourself the 4-pin header.

bug?
 

I noticed a possible bug with the 0.4.1 firmware.

If you select channel speed and change to channel 2, you can't use the wheel to change between throttle speed and the throttle speed on/off setting. You need to go back to channel 1, turn the wheel to change to the other function and go back to channel 2 to change the value.

Or maybe I don't understand to operation of this setting? Possible. :)

Thanks!

edit:
user error. I needed to use the throttle, not the wheel. sorry!

When adjusting any setting for channel 2 use the trigger to change direction rather than the wheel.

got it!

thanks!

how is the latency issue with the mods

+1

I would like to know if the firmware update improves issues with the slow latency. I bought this radio and personally the transmit speed are too slow to run any 17.5 blinky touring car.

I bought this radio thinking that the latency would not be a problem but it truly is for any fast road course racing. I borrowed a fellow racers bottom of the line Spektrum radio and receiver and was able to to be competitive as the car reacted quickly. The Flysky felt like it had almost a full second delay after my steering and throttle input. I'm using Futaba 9551 servos and a Tekin Pro ESC.

Just ordered from losikid I'll let you know about latency problems if it had any

Is it possible to mod a potmeter instead of the switch to channel 3? Will the PSX fw cope with it?

yes, and I believe the alternate firmware can use it.

No, its supposed to work, but it don't. I've been looking through the code to try and figure out why, but i haven't seen nothing yet...

Thanks Losikid, some crawler guys around here want this feature to have smooth control over an added braking servo.

Interesting, mechanical brakes on a crawler...got a picture?

ok i hope you guys can help me out i will buying this radio real soon and will be doing the 8ch mod to this radio for a rc truck build im doing

when the 8ch mod is done to this radio can i put a potentiometer on each of the other ch so they work just like channel 1 and 2

i will be taking this radio apart and building a custom stick radio out of it

any info will help

Not yet, they're in the planning stage.

If it don't work, just write me what exactly You did, how You setup model in radio config and what it was doing then. I will try to look at it at the code.
Maybe I can try to temporarily connect potentiometer to CH3 button and test the same things You did.
And do You see changing values at calibrate screen for channel 3, when You have potentiometer connected ?

so much info thank you very much losikid

I am curious for this answer also

1) The additional channels are controlled by the stock buttons?( trim buttons etc) or are more buttons physically added to the radio??
2)Are the additional channels 2 or 3 position?
3) can a pontentiometer be added to any of the channels?
4) how many models can be controlled? I have seen 14 and 40 mentioned?
5) the website mention a trade off of channels vs number of models- so what are the trade off specs?ie 8 channels have 10 model memory? 6 channels has 14 model memory?
6) will the radio come with additional programming instructions or is there a PDF link for instructions on the website?

Thanks I am a technical nut and want to get as much info as possible before ordering