GT3CFirmware Hack KitInstallation

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Step 1:Locate a clean area to preform the modifications. An ideal location is somewhere without

carpet flooring. This is because carpet tends to easily create static electricity which, if discharged onto the GT3C’s internal components, can cause serious damage. The following tools will also need to be gathered before beginning the modifications.

• Small-Medium Phillips head screw driver, and a small flat head might be needed• A decent soldering iron with a small tip (anything bigger than an 1/8” tip is not ideal)• Rosin Core Solder (63/37 is ideal, but 60/40 and others will work)• Hobby Knife (Xacto knife or similar) with a new blade. • Small pair of pliers or needle nose pliers• Time and patience

A

C

E F

D

B

Step 2:There are two screws hidden beneath the rubbers by the

areas marked A & B. These screws need to be removed. Once the screws are set aside the top piece is held on by plastic at locations C, D, E, & F. The best way to unlock these clips is to take your fingernails (start at A&B) and run them between the top piece and the main handle while applying inward pressure. Usually once C&D have be released E&F takes little effort. If you can’t or prefer not to use your fingernails, then a flathead screw driver or similar can also be used, but it may result in some cosmetic damage.

Once the top cover is off, there is 3 cables attached to the main circuit board. Gently disconnect these cables by pulling on their plugs, not the wires. Sometimes a small flat head screw driver, or other prying utensil, may need to be used to disconnect the cable.

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Step 3:Now, the programming port needs to be installed. Todo this, gently pull up on area A, then

work the pins on the port down into the holes. Once the port is in the holes, position it so its flush with the outer plastic housing, the pins should also be be snug with the back of the holes. Now, it needs to be soldering in place. Use the following steps to aid the soldering process,

A

Soldering the port to the board-• Begin by ensuring there is a clean tip

o Do this by melting some solder on the tip then wipe it off with a wet sponge

• Now lightly tin the iron’s tip by applying a small amount of solder to it

• Then, place the iron on both pin B and its solder pad.

o Heat both for 1-2 seconds• Now apply solder to the pin and pado The iron should still be heating the pad and pin

• Remove the iron, and inspect to make sure the port is still flush with the outer plastic housing

o It most likely isn’t, so to make it flush, reheat the joint from the backside then position the port correctly, and hold it in position as the

iron is removed and until the joint has cooled.• Once port is flush with the outer housing,

solder the other 3 pins

B

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Step 4:With the port soldered to the board, now a slot in the radio housing needs to be made to allow

for external access which will make flashing updates easy. To begin, place the top section back into the main housing, and gently try and snap the plastic latches back in to ensure that the top piece is centered correctly.

Now take the xacto knife and make a light cut at the edges of the port, only go about 1/8” down the side of the radio.

Here’s a tricky section, the marks made earlier now need to be cut down. The best way to

do this is to take a xacto knife, start at the top and slice down about 1/8”. IF the blade isn’t ultra sharp,

then some moderate pressure and rocking the blade back and forth with help cut plastic. Also, heating the

blade up can help. Once the cuts are made, make a very light straight pass along the bottom connecting the two. Then

keep taking passes with abit more pressure till the groove is about 1mm deep. Once there is a good groove, take a pair of pliers and peel the

pieces off backwards towards the inside of the radio. Now, plug the wires back in, pop the top back on, screw the screws back in, replace the rubbers, and the

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Step 5:Now you need to download and install the programming software, ST visual programmer. It

can be download with/from this link http://www.overkillrc.com/GT3B/STVPInstall/sttoolset.exe If you are running windows 7 and possibly vista you may need to install this patch as well, which can be found at this link http://www.overkillrc.com/GT3B/STVPInstall/sttoolset_pack24_patch.exe Make sure restart your computer after you install. Once you have rebooted your computer, open up ST Visual Programmer and make sure you have these settings, first time you open it, it should let you choose, however if it doesn't, click on the configure tab, then configure ST visual programmer.

Also, now is a good time to download the firmware file, the GT3C requires a firmware version 0.6.1 or newer to operate correctly. The latest firmware file should have been emailed when the hack kit was purchased, however to access the newest firmware please visit http://www.overkillrc.com/Gt3X-Firmware/

Make sure to download it to a known location (such as the downloads folder or desktop), as this file will need to be located in order to flash a new firmware on the radio.

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Step 6:

Close out of STVP; now plug your radio into the programmer.. The GREEN wire needs to be on the SB1 side on your programmer, and towards the front side of the radio* (st wheel side)*First the 4 pin adapter needs to be added to the 4 pin cable. The long pins go into the cable and the short pins go into the radio

Now plug the programmer into the computer with the supplied USB cord.

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• Now open up STVP.• Click File,

o open, • Select the firmware you want to use. • Now click program,

o Current tab. There should be a status bar on the bottom. It will program then verify. Don't do anything till it says verification complete.

Step 7:Sorry, no pictures at this time. But now its time to 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 entero 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 voltageo “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

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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 enter, scroll to H, press enter, scroll to E_R. press and hold enter for 1-2 seconds.

This changes the low voltage alarm to 3 volts and reverses the scroll wheel so it acts normal.

Step 9:This is kinda another optional step. The early GT3C’s (at the time of this guide and all

beforehand) have a fault with the power button in the steering wheel. There are two little plastic columns in the steering wheel assemble that are supposed to act as “guides” for the power switch wires. However, these guides actually snag the wires and pull them off the power switch. So the solution is to cut them off with a pair of snips or pry them off with some needle nose pliers

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Step 10:Introduction to programming: This section is to help make the learning curve for the new firmware not quite as steep

So to begin with, the basic functionality is the same as it is stock. The menu items are what the say they are with a short enter click. To adjust the EPA’s, simple go to E.Point, press enter, choose the channel, press enter and adjust them. For menu’s that can have both a left and right value, such as EPA’s, use the steering wheel to switch between the left E.Point and the right E.point. There will be an arrow above the 3 digit display.

The initial complexity most run into is programming the more advance functionality. Which is actually quite simple if one was to take the time and read the firmware manual. Due to the limited lcd on the GT3C, abbreviations are used to show whats going on. These abbreviations are all laid out in the manual, but here’s some info on the basics.

Behind each normal menu item, there is an secondary menu. The secondary menu is accessed by using the LONG-enter maneuver (press and hold enter for 1-2 seconds). Each menu can have a long list of sub menus or “options”, to navigate through these simply press enter. At each menu (option), select a value for it, then proceed by pressing enter. LONG-enter will save and exit a menu.

The manual lays out all these menus, their options, the signals that indicate which menu is open, and the order which menu’s come (top to bottom=first to last). The manual also gives a brief description of each option. The firmware manual is not a how to, is is simply a map that shows how to get to the place to adjust something, and what the abbreviations mean.

Here are afew templates (How to’s) to get started Assign Channel 3 to the Ch3 Trim Switch as a non momentary 3 position switch

• Scroll to REV, press LONG-enter (access the Key Mapping Menu)• Scroll to 3, press enter (Select the CH3 trim switch)• Scroll to CH3, enter (Choose to control Channel 3 with the chosen switch)• Scroll to BNL, enter (Select No Long keys from the Buttons menu/option)• Scroll to 100, LONG enter (Select 100% as the step rate, so positions is -100%, 0, 100%, then

exit menu as other options arn’t needed) Assign the DIG mix (dual esc) to Channel 3 and have the CH3 trim switch control it in a momentary action)

• Scroll to E.point, LONG-enter (Open the Mixing menu)• Scroll to d, enter (Select the DIG mix)• Scroll to CH3, LONG-enter (Assign the 2nd esc in the DIG mix to be ch3, then exit the menu)• Scroll to REV, LONG-enter (Open the Key-Mapping Menu)• Scroll to 3, enter (Select CH3 Switch)• Scroll to DIG, enter (Select the DIG mix as the function controlled by the selected switch)• Scroll to BMO, LONG-enter (Select MOmentary from the Buttons menu)