GT3B Hack Question and Answer Thread

[RCCrackHead]

Been there done that, talks nothing about performance or AFHDS vs AFHDS2.

[losikid]

Originally Posted by RCCrackHead

Been there done that, talks nothing about performance or AFHDS vs AFHDS2.

Is a $40 radio with absolutely no potential beyond stock.

And why are you asking about AFHDS2, NONE of the radios you mentioned is using AFHDS2

[RCCrackHead]

It shows that it comes with the FS-A3 receiver that should operate on 2.4GHz AFHDS2A signal.

[losikid]

The box and description says AFHDS...This isn't a flysky branded tx/rx. Dimension can give this stuff whatever name they want.

[claycity]

I got a request. Can we stop talking about radio that are not GT3B. With over 200 pages now the thread is getting harder to keep up with. This thread is the only thread I look at when comes to anything about my GT3B. I love and want to thank all the hard work put into the GT3B. Thanks Greg

[Savagethrash]

Just through my order in for a GT3B firmware kit. Then realized I have the GT3C... Will I be able to make it work with some direct soldering or buy using a few header pins I have laying around?

[CODYBOY]

I just hacked mine with a two year old kit. Or I should say my wife did. I was having problems with the links up loading right and asked her to help. I had everything hooked up to my gt3c and computer and went out to the shop, leaving all the directions by the computer. Next thing I know she comes out and says the red light is flashing on the board, you need to do the rest!!!!
So yes it will work.

[Savagethrash]

Originally Posted by CODYBOY

I just hacked mine with a two year old kit. Or I should say my wife did. I was having problems with the links up loading right and asked her to help. I had everything hooked up to my gt3c and computer and went out to the shop, leaving all the directions by the computer. Next thing I know she comes out and says the red light is flashing on the board, you need to do the rest!!!!
So yes it will work.

Wonderful! Thank you!

[losikid]

Originally Posted by Savagethrash

Just through my order in for a GT3B firmware kit. Then realized I have the GT3C... Will I be able to make it work with some direct soldering or buy using a few header pins I have laying around?

They are the same programming just different headers.

Do you want me to change your order to a gt3c kit?

[Savagethrash]

Originally Posted by losikid

They are the same programming just different headers.

Do you want me to change your order to a gt3c kit?

If you could that would be great. I don't know how difficult it is to ghetto fab up what I'll need to flash it with the B. I have 2 radios to do, this way I'll only have one radio that requires a little extra work. I'll PM you my order number.

Can't PM, the order number is OK-1536

Stoked to unlock these radios and throw some holmes BR minis in the rig

[losikid]

Originally Posted by Savagethrash

If you could that would be great. I don't know how difficult it is to ghetto fab up what I'll need to flash it with the B. I have 2 radios to do, this way I'll only have one radio that requires a little extra work. I'll PM you my order number.

Can't PM, the order number is OK-1536

Stoked to unlock these radios and throw some holmes BR minis in the rig

fixed, and I'll include a second gt3c header...

[Savagethrash]

Originally Posted by losikid

fixed, and I'll include a second gt3c header...

Feel free to pm me your PayPal, appreciated.

[losikid]

Originally Posted by Savagethrash

Feel free to pm me your PayPal, appreciated.

Don't worry about it

[Sapes]

I've had my radio for only a month now but it doesn't seem to be working properly to me. I was trying to use the exponential function today however it didn't seem to work properly. It acted more as a trim function rather than exponential. When I adjusted the expo, the vechile would start moving forward without me touching the throttle, or if I adjusted it the other way it would go in reverse as though I were adjusting the sub trim. I don't have this prohlem on my futaba radio. Anyone else have problems with the expo funtion? I wanted to soften my thottle but expo doesn't work.

[Brainanator]

Just wanted to post up my thanks to losikid for all his work. I've used your tutorials (and your troubleshooting posts in this thread) to hack 2 radios for myself. Running 6 channels on my scalers. Whenever someone asks where they can get a radio I refer them to overkillrc.com. Don't think anyone has followed through yet though, since I seem to be one of the only RC guys here locally that is really interested in the electronics part of RC.

[losikid]

Originally Posted by Sapes

I've had my radio for only a month now but it doesn't seem to be working properly to me. I was trying to use the exponential function today however it didn't seem to work properly. It acted more as a trim function rather than exponential. When I adjusted the expo, the vechile would start moving forward without me touching the throttle, or if I adjusted it the other way it would go in reverse as though I were adjusting the sub trim. I don't have this prohlem on my futaba radio. Anyone else have problems with the expo funtion? I wanted to soften my thottle but expo doesn't work.

I don't have this issue.

Make sure your radio is calibrated (turn steering wheel max clockwise then enter-LONG to enter the calibration menu)

Also, are you using any trim?

[m1009cucv]

finally hacked mine. 3ch doesnt work at all. any idea why?

reading is this very long thread. i never Calibrated the radio after I hacked it. going to start there

[losikid]

Originally Posted by m1009cucv

finally hacked mine. 3ch doesnt work at all. any idea why?

reading is this very long thread. i never Calibrated the radio after I hacked it. going to start there

You have to map channel 3 to switch in the key mapping menu

[m1009cucv]

I kinda suck with electronics. Whats that mean in English haha

[losikid]

Its the heart and soul of utilizing all the channels on the GT3B/GT3C

Directly from the manual

- Key mapping specific for each model:
    > choose menu REV and press ENTER-long
    > menu REV will blink
    > choose trims (id: 1 2 3 d) or other keys (CH3: C, Back: b, End: E) or
        if trim is OFF, then also trim keys (id 1 2 3 d with left/right arrow)
    > press ENTER and modify first setting
    > press ENTER and modify next setting
    > ....
    -----
    steps of settings of trims (1 2 3 and D/R):
	- sequence:
	  function -> buttons -> step -> reverse -> opposite_reset -> previous_val -> rotate
	- function: selected function listed at the end of manual
	- B buttons:
	    MO - momentary, hold left/right trim key to get end values,
		 when nothing pressed, servo is at center
	    NL - no long keys, long press is the same as short press
	    AR - autorepeat is on
	    RS - long press of one of trim keys will reset to
		 centre/reset value
	    EN - long press of trim key will set to coresponding end value
	- step: select trim step for one trim key press (1, 2, ... 100, 200),
		not available when buttons MO or fuction is list of items (multi-position)
		is identified by symbol "V"
	- RE reverse:
	    0 - no change
	    1 - swap left/right trim keys
	- OR opposite_reset: not available when buttons MO
	    0 - no change
	    1 - when trim key is pressed and value is at opposite
		side of center/reset, set value to centre/reset,
	- PV previous_val: available only when buttons MO or fuction is list of
			   items (multi-position)
	    0 - no change
	    1 - instead of setting value to centre/reset when key is released,
		it is set to previous value, which was active before key press
	- RO rotate: available only if fuction is list of items (multi-position)
	    0 - no rotate
	    1 - rotate from max item to first item and back
    -----
    steps of setting of keys (C b E 1< 1> 2< 2> 3< 3> d< d>):
	- sequence:
	  function -> momentary -> reverse -> prev_val -> function_long -> reverse_long -> prev_val_long
	- function: selected function listed at the end of manual
	- MO momentary: only available for 2-state functions (channel, ...)
	    0 - switch, key press will switch something (channel value, ...)
	    1 - momentary, value change will be active only while key is pressed
	- RE reverse: only available for 2-state functions
	    0 - normal, no-press or default value is left endpoint
	    1 - reverse, no-press or default value is right endpoint
	- PV prev_val: only available for 2-state functions
	    0 - key release or OFF state sets value to left endpoint (noREV)
	    1 - key release or OFF state sets value to value active before
		  key press or ON state
	- function_long: function applied when long press of key happens,
	                 choose from the same list as function,
			 identified by "V" symbol
	- reverse_long: same as "reverse" + "V" symbol
	- prev_val_long: same as "prev_val" + "V" symbol
    -----

Functions assignable to trims:
==============================
OFF		- nothing, it is possible to assign each button individualy
		  as key
TR1, TR2	- trim of channel 1/2
DRS, DRF, DRB	- dualrate of steering/forward/back
EXS, EXF, EXB	- expo of steering/forward/back
CHn		- change channel "n" value in range -100...100
STn		- subtrim of channel "n"
SST		- steering speed turn 1...100%
SSR		- steering speed return 1...100%
CSn		- channel speed for channel "n" 1...100%
4WS		- 4 wheel steering mix -100...100%
DIG		- DIG throttle mix -100...100%
MP1		- Multi-Position 1, switches position up/down
MP2		- Multi-Position 2, switches position up/down
MP3		- Multi-Position 3, switches position up/down
MP4		- Multi-Position 4, switches position up/down



Functions assignable to keys:
=============================
OFF		- nothing
CHn		- switch channel "n" value from one end value to opposite end
		  value. There is special handling for CH3 button. When using
		  3-position switch instead of CH3 button and momentary is
		  selected for this button, then centre 3-pos value will also
		  be detected and set to servo (use 1K resistor to GND to get
		  middle state)
CnR		- reset value of channel "n" to centre
4WS		- switch crab (CRB) no-crab (NOC) for 4 wheel steering
DIG		- switch DIG mix between -100 and 100 (more useable when using
		  return to previous val key setting)
DGR		- reset DIG mix to centre
MP1		- Multi-Position 1, switches position up (at END back to 1.)
MR1		- Multi-Position 1 Reset, switches position to first one
MP2		- Multi-Position 2, switches position up (at END back to 1.)
MR2		- Multi-Position 2 Reset, switches position to first one
MP3		- Multi-Position 3, switches position up (at END back to 1.)
MR3		- Multi-Position 3 Reset, switches position to first one
MP4		- Multi-Position 4, switches position up (at END back to 1.)
MR4		- Multi-Position 4 Reset, switches position to first one
T1S		- start/pause timer1
T1R		- stop + reset timer1
T2S		- start/pause timer2
T2R		- stop + reset timer2
BRK		- switch on full brake, this overrides throttle position
BLS		- battery low shutup, stop beeping, predefined to END-long

Also take a look at this link

http://overkillrc.com/GT3X-Firmware/...lp%20cards.pdf