GT3B Hack Question and Answer Thread

[heyok]

Has the transmitter had the firmware updated? If so, I would start by calibrating the controls as it sets the high, low and mid points of the throttle and steering. It also will display a number indicating the controls position. Maybe do a calibration procedure, then either monitor it with a servo like you just did, or watch the display.

You should be able to find a replacement pot somewhere - the trick is making it fit.

[JesterSpec]

firmware is 061, I've calibrated the esc multiple times, and after a bit of time, something looses the calibration. I'll check around in menu's on the radio to see if I can find something to show the number of the control position.

Throttle dead zone is at 10 on a scale of 0-50, I tried to swap it around with no changes.

If I let the tx sit, the forward throttle will start to creep as shown on the esc and motor noise. I'll bump reverse, then it will start to creep again after about a min.

I may be further ahead to buy another 3b and just use it for parts.

[heyok]

I meant transmitter calibration, not your ESC calibration.
This is how you get to the Calibration menu - I've kind of pieced this together from two different places:

Calibrate menu:
===============
- enter it by wheel right-turn and ENTER-long
- 6 menu items starts to blink (+ 2 arrows if CH3 is potentiometer)
- use END or ROTATE to change channels

This is stolen from the firmware installation manual:

calibrate the radio.
• First, measure the voltage of the lipo for the GT3C
• Install lipo, and turn on the radio
• After power up, the screen will display CAL for afew seconds, then turn to a screen where 6
menu items blink, a digit is displayed on the left, and 3 digits are displayed on the right
o The left digit should be “1”, this means CH.1 (st. wheel) is being calibrated
• Once numbers are steady, press enter
o You’ll notice the middle menu item on top row stops blinking. These menu items represent
left/center/right calibration values for channel 1 (top) and channel 2 (bottom)
• Hold st wheel max counter clockwise, wait till numbers steady out, press enter
• Hold st wheel max clockwise, wait till numbers settle, press enter
• Now channel 1 has been calibrated, now rotate the enter wheel so the left digit displays 2
o This means channel 2 and/or the trigger is being calibrated
• When trigger is at neutral, and numbers steady out, press enter
• Pull trigger to max, wait till numbers steady out, and press enter
• Push trigger to max, wait till numbers steady out, press enter
• Now channel 2 has been calibrated, rotate the enter wheel till 4 is displayed. This is to calibrate
the battery voltage
o “3” is not important at this time
• Once 4 is displayed, press enter. Rotate the enter wheel to the voltage that was measured before
power up. The press enter, now press and hold enter for about two seconds . This is called a
LONG-enter, which exits and saves the current menu that is open.
o After the LONG enter, the lower power alarm will be buzzing. This is normal, proceed to
step 8
v0.0
Step 8:
This step is for firmware 0.6.1, possibly others. In 0.6.1, defaults are setup for the GT3B. To
change the defaults, turn the radio off, then back on. Now press and hold enter for about 2 seconds
(LONG-enter). This will open the global setup menu. Scroll until LOW POWER is blinking, press
enter. scroll to 3.00v, press and hold enter for 1-2
seconds.

[ik632]

I had an issue with a radio that I didn't calibrate the throttle on. It had a similar issue. I had just turned the wheel and throttle and didn't hit enter while holding.

[JesterSpec]

Gave it a shot, throttle would not stabilize at any number, centered, full on, full off, all numbers were jumping around. Tried my best to calibrate, rebound, recal'd esc. same problem.

I just redid the cal, and noticed that when pulling the trigger and releasing that instead of dropping to the neutral number, it slowly decreases. Eventually it gets there, but not right away. Reverse dropping to the neutral number is the same way, slow, and seems to stutter before it gets to the cal number.

I appreciate you finding the info for me! I didn't do the instal on the software so I wouldn't have known that you calibrated it after installing.

[jaloos]

How far out did the numbers drift when you tried to calibrate it. A bit of drift with a "big buck unit\' like this is understandable.
If the drift wasn't bad then I would calibrate it again.

Do you have the discovery board to re flash it ?

If so try to flash it again with a fresh firmware file in case the one you used was corrupted.

[JesterSpec]

It wasn't the drifting that I think is the problem, More that the trigger pot is REALLY slow to return to center. Not the trigger itself I mean, but the numbers. The trigger will be centered, and the numbers will still be 20-30 off from center as they slowly work back to neutral.

[Charlie-III]

Originally Posted by JesterSpec

It wasn't the drifting that I think is the problem, More that the trigger pot is REALLY slow to return to center. Not the trigger itself I mean, but the numbers. The trigger will be centered, and the numbers will still be 20-30 off from center as they slowly work back to neutral.

Might be time to pull the throttle pot & clean it with contact cleaner (electrical/electronics type..... NOT eyeball type... ....).

[JesterSpec]

Sounds like a good project for this morning. Rainy and miserable here...

[Charlie-III]

Originally Posted by JesterSpec

Sounds like a good project for this morning. Rainy and miserable here...

Ditto here..... good "inside project day"!

Let us know how it works out.

[JesterSpec]

Tore into the TX, Sprayed down the Pot with Cow-RC moo-tor cleaner/degreaser and so far its working. We shall see if it is a lasting fix.

After I cleaned the Pot, I recalibrated the TX. When testing the Throttle Cal, full throttle was around 40, neutral was 640(or 540 can't remember) is, and full was 900(I think).

Full throttle to neutral would drop to around 620. Reverse to neutral would go to 640. BUT sometimes full throttle to neutral would to to 640, so I calibrated neutral to 640, and its working.

Thanks for the walk through

[Charlie-III]

Originally Posted by JesterSpec

Tore into the TX, Sprayed down the Pot with Cow-RC moo-tor cleaner/degreaser and so far its working. We shall see if it is a lasting fix.

After I cleaned the Pot, I recalibrated the TX. When testing the Throttle Cal, full throttle was around 40, neutral was 640(or 540 can't remember) is, and full was 900(I think).

Full throttle to neutral would drop to around 620. Reverse to neutral would go to 640. BUT sometimes full throttle to neutral would to to 640, so I calibrated neutral to 640, and its working.

Thanks for the walk through

Sounds great, thanks for the follow-up. I've suggested the same before (GT3B/C and other radios, clean the throttle pot) but never get feedback.

Hopefully it stays well for a long time.

Note, the resistive material WILL wear off the pot plate over time, thus it may get "jumpy" when going through it's travel. Then, it's time to replace the pot.

[ik632]

I wonder if its worth it to use some deoxit on that. I w used it on pots in vintage electronics.

[Richterat83]

My Flysky and hack kit came in today and already modded, but i'm having trouble finding the program to actually program the radio. I found the patch for Windows 7 and firmware, but it's telling me i don't have the toolset installed.

Anybody have a link or a copy of the needed software?

[Charlie-III]

Originally Posted by Richterat83

My Flysky and hack kit came in today and already modded, but i'm having trouble finding the program to actually program the radio. I found the patch for Windows 7 and firmware, but it's telling me i don't have the toolset installed.

Anybody have a link or a copy of the needed software?

Check on the hack kit page on OverkillRC's site (site link in my sig.)

[Richterat83]

Odd. . .i tried the links provided in the install guide but it kept coming up that the site is down and i was visiting an old webisite. Either way, they're working now (on home laptop vs work computer earlier, which i have admin rights, so i'm not sure what's up there)

Either way, thanks again Charlie!!

[Richterat83]

Oh boy, shoulda just waited to buy one modded.

I was able to get the software to work as well as flash the latest firmware, but, now the radio won't turn on. no backlight, no LCD.

I had a low bat alarm, so i turned it off and plugged it back in, 10 minutes later, green light, as if it were fully charged. Unplugged, go to turn it on, and it does nothing.

It was working pre-flashing (although backwards, forward went backwards on throttle) but steering worked.

Not sure what's going on. I can still connect the radio to the computer via USB and i can still program memory and verify, but i can't turn the radio on

edit: Scratch that, loaded my own firmware only to replace with the latest provided by Losikid and it turns on now. But i can't get the CAL screen to show to setup calibration now

[Charlie-III]

Read down this page, there is a post with how to get into calibration mode (HeyOK did the post).

[Richterat83]

Found the post about calibrating. I'm retarded and was trying to turn the enter wheel rather than the steering wheel. That's done, now trying to bind it to the 8 channel Flysky RX

And after downloading the flysky PDF, she's bound.

Now to learn programming it lol

[Dilling90]

Wow a lot of helpful and cool stuff here, may have to look into some of this programming stuff in the future, the only issue I have with my skyfly is no matter what receiver (I have 4) esc or motor I use, my scx10 and wraith both lurch in reverse instead of being smooth like when they go forward