TQ Link 2.4GHz - 2 to 4 Channel Mod

[danielhr77]

Hello Guys,

Well, I got my Slash 4x4 last week and I wanted to have at least 1 more channel on my radio system to turn on/off the lights remotely... If you remember, I was the first to find out how to convert the old TQ 2.4Ghz transmitter from 2 to 4 channels when I got my ERBE last year... If you don't remember it, check my thread about it: http://monster.traxxas.com/showthread.php?t=465950

So, after a few emails and PMs about this, I was wondering if it was possible to convert the new TQ Link 2.4GHz transmitter from 2 channels to 4 channels (we already have a 5-channel receiver on the truck)... And, the answer is again, YES!!!

I must admit this mod was very easy to do because the new TQ 2.4Ghz Link is fully digital (no trims or switches)... On the old TQ 2.4Ghz transmitter, I had to add and remove a few parts on the board, and I spent some time trying to figure it out...

As I always say, this mod is working just fine for me, but, this will void your warranty and I'm not responsable if you ruin your transmitter...

I suppose you know how to open the new TQ Link 2.4Ghz transmitter: 5 screws on the back, remove the plastic cover from the on/off switch, remove the battery holder and the 2 screws on the board...

After that, you can see 4 empty pads on the board that says: UP DWN (RSW) and UP DWN (ISW)... You have to connect 2 switches to those 4 pads... I used a three positions switch, that is: OFF-ON-OFF (for the Summit's T-Lock)... But, you can also use a two positions switch, that is: ON-OFF (for the Revo 3.3 reverse)...



I labeled the pads and also the switches so it's easier to follow... As you can see, pads 1 to 4 goes to the exterior legs on the switches (yellow and green wires)...



Also, you need to connect the middle leg on both switches (white and purple wires) to ground... I used an empty ground pad on the top board where the trims are...



This is how my temporary setup looks on my new TQ 2.4Ghz Link...



And, a video to prove that it works...



Hope you like this new mod... Now, I can use it on my Summit!!!

Daniel.

PS: I'll try to find out if it's possible to make the 5th channel work...

[RAVIN]

Thanks!! I'm on it.

[Super Dude]

I'm not gonna be tryin it any time soon, but good job anyway.

[PeterV]

Very creative, Daniel! Looks like your 2-channel radio's board was calibrated as a 4-channel. There may be a few other Traxxas 2-ch TXs with which this mod will work, but all our 2-ch systems should be calibrated as 2-ch, which means the extra positions on the board will not work if you hook switches up to them. So, if you perform this mod and the switches don't work, that's why...but you'll still have a voided warranty!

[cnj]

Peter, any updates on when the new 4 channel Link transmitter will be available?

[PeterV]

Let me ask...

[padrino]

Great work! I just sold my extra 2CH High Output system a couple of dys ago thinking it couldn't be done, looks like I'm out to buy another since my 4CH High Output is still on backorder and I am seeing some sites push them into March.

PeterV, please share if you can. I have watched it go from Jan to almost March now and it's definitely frustrating since I've been sitting on my Summit for a while now waiting for something.

[danielhr77]

Very creative, Daniel!

Thanks!!! I like to do these things...

Looks like your 2-channel radio's board was calibrated as a 4-channel.

Actually, my 2-channel radio's board was calibrated as a 5-channel, but I can't seem to find the 5th channel yet...

I'll keep researching because it's not obvious like the 4 pads on the board...

[RAVIN]

[IMG][/IMG]

[RAVIN]

Done!!!!!!

[danielhr77]

Nice work!!! I'm glad it's working for you too...

[padrino]

Done!!!!!!

Is that the 2CH link modded in a 4CH case and switches?

[RAVIN]

Is that the 2CH link modded in a 4CH case and switches?

It's the 2ch with the 4ch switches I cut and drilled it.

[padrino]

It's the 2ch with the 4ch switches I cut and drilled it.

It looks good, did you get the switches from an old unit or can you buy them somewhere?

[RAVIN]

It looks good, did you get the switches from an old unit or can you buy them somewhere?

I used the switches from the stock summit radio.

[danielhr77]

I think I found an easy way to know if the transmitter has the 3rd and 4th channel enabled...

Basically, I guess, you shouldn't be able to configure more than 2 channels on the transmitter, but, in my transmitter I was able to configure up to the 5th channel...

Check my video, you'll see the green LED blinking five times at the end...



That's the way I discovered that my transmitter had those channels enabled...

[padrino]

I think I found an easy way to know if the transmitter has the 3rd and 4th channel enabled...

That's the way I discovered that my transmitter had those channels enabled...

Was this tried before you modded or do you not think it matters? I just tried it on mine (stock 2CH from Slash 4x4) and it only allows 2 channels.

I wonder how simple that little control port on bottom is to figure out, not sure if they did something basic or more complicated since I expect one can turn on whatever they want if it's sorted out.

[danielhr77]

Yes, I tried it before I modded it and I think that's the key to make it work...

I guess if it's not working for you it's because the microcontroller on the board wasn't programmed to do that...

So far, I know two that worked and two that didn't... Just luck, I guess...

[padrino]

Yes, I tried it before I modded it and I think that's the key to make it work...

I guess if it's not working for you it's because the microcontroller on the board wasn't programmed to do that...

So far, I know two that worked and two that didn't... Just luck, I guess...

For the ones that worked, outside of yours do you know how new they are? Mine is a couple months old at this point so it's early in the production cycle, I wonder if they flipped recently when they started making the 4CH units.

[zrau17]

good job. now just out of curiosity, in the top picture all the way at the bottom you see the (battery -) and (battery +) labels, is that the spot to put leads on for rechargeable batteries?

[padrino]

Two quick questions..

Two posts up, can you comment on the release date of the radios you are using, some of the first or recent Slash purchases?

RAVIN, did you see my PM?

[danielhr77]

Sure, I bought my Slash 4x4 from Tower 2 weeks ago...

[padrino]

Sure, I bought my Slash 4x4 from Tower 2 weeks ago...

Thanks, it seems there may be something to it since I pinged a number of people on ebay and RC Tech with units for sale and quickly found one that shows 5 channels just like yours. It's on it's way now and with Tower moving my backorder for the factory 4CH version to March I am going to make my own as well .

[RobWilJas]

I've got three of these radios and just tested them, all three are capable of 5 channels. Time to start modding lol.

[microwebtech]

Thanks for the info, mine shows 5 blinks. 5 channels

[microwebtech]

I also checked my other 4x4 that was still in the box.
It is also 5 channel ready.
This one has RED menu and set BUTTONS.
I suppose the latest radios have RED buttons?
Anyone else have one?

[RobWilJas]

Of my three, two have red buttons and one has yellow buttons.

[cnj]

Bummer! Both of mine only blink twice (2 channels). Incidently, they also have yellow buttons.

[danielhr77]

Nice!!! This thread became popular... Hope Traxxas doesn't hate me...



PS: if someone wants to sell one (5ch) cheap with int shipping, please pm me...

[Evgen]

i'm interested too for around under $50 with int. shipping

[mavrim]

Actually, my 2-channel radio's board was calibrated as a 5-channel, but I can't seem to find the 5th channel yet...

I'll keep researching because it's not obvious like the 4 pads on the board...

Daniel,

I did your mod to a 2.4ghz Link Hi-Output transmitter and I was able to get all channels to work. The funny thing is that all 5 are available, you just did not realize it!

I ran 4 wires from the pads you mentioned. One pair of wires are for the third channel (RSW - up/down), which is rear steering for my TXT-1 Monster Truck. I mounted two momentary pushbuttons above the steering wheel (one in each of the diagonal end pieces). Up goes to one switch and down goes to the other switch. Ground is connected to the 2 unused connections on the switch. So now by pressing the top button my wheels turn and then center when released. The opposite when I press the other button. When using the wheel to control the front steering, I can press either button to steer the rear.

This is where the 5th channel comes into play. I mounted a 3 way switch that is on-off-on and wired that to the other pair of wires (ISW - up/down). The center of this switch is connected to ground. I thought the 4th channel servo would go from neutral to left or neutral to right, like the rear steering did. I was wrong! I found that by flipping the switch from ground to ISW up would rotate the 4th channel servo and ISW down would rotate the 5th channel servo. So now I plan to add one more switch so that the 4th and 5th channels can be separated. For the mean time I can only choose either the 4th or 5th channel by using the one switch.

The wiring I described is identical to the pictures you show! In your video, the second switch is only controlling one servo and one direction only. Connect another servo to channel 5 and the same wiring will control it.

I was baffled by 2 channel 1's on the receiver, until it dawned on me that the summit used dual steering servos and there are connections for both servos to plug in (rather than using a Y adapter).

[EMAXX ab USER]

For some reason when I tried my new link controller it at first only blinked twice showing me that I had a 2 channel tx and not the 5 I hoped for. I decided to try it again following the video a second time. Now the tx is blinking 5 times. I tried it again and its still blinking 5 times. Woo hoo. Not sure why it blinked only twice the first time I tried but im glad I tried it again. Thanks for the mod info Danielhr77

[digi]

I just checked mine that came with my Rustler about a month ago (serial# A0006969), and it will only blink 4 times, after that it goes back around to 1 blink. Should I still be able to mod it for 4 channels?

[EMAXX ab USER]

Daniel,

This is where the 5th channel comes into play. I mounted a 3 way switch that is on-off-on and wired that to the other pair of wires (ISW - up/down). The center of this switch is connected to ground. I thought the 4th channel servo would go from neutral to left or neutral to right, like the rear steering did. I was wrong! I found that by flipping the switch from ground to ISW up would rotate the 4th channel servo and ISW down would rotate the 5th channel servo. So now I plan to add one more switch so that the 4th and 5th channels can be separated. For the mean time I can only choose either the 4th or 5th channel by using the one switch.

Please post a wiring diagram of the seperated 4th and 5th channels please.
I would like to see how this arrangement is done. Thanks

[mavrim]

Please post a wiring diagram of the seperated 4th and 5th channels please.
I would like to see how this arrangement is done. Thanks

It is the same wiring diagram that Daniel posted at the top of this thread!

He must have not had the 5th channel servo plugged in and assumed that there was no channel switch connections available? I connected both the 4th and 5th channel servos. The same switch that daniel shows in his wiring must be a 3 way switch, meaning that the center is open and having 2 positions (on - off - on). When the switch is toggled in either direction, it causes that wire to be grounded and control the appropriate servo.

[EMAXX ab USER]

Oh I thought you had seperated the channels and had them working seperately...er well like the 3rd channel. I played around a bit with the 4th and 5th but I couldnt make sense of how i could make them seperate from each other.

[mavrim]

Oh I thought you had seperated the channels and had them working seperately...er well like the 3rd channel. I played around a bit with the 4th and 5th but I couldnt make sense of how i could make them seperate from each other.

It is easy to separate the switches. In Daniels wiring diagram, he shows ground going to the center of the 3 way switch. The other 2 contacts on the switch go to the connections on the printed circuit board. If you want to separate them like I plan to do, then Connect ground to both switches and the other contacts go to the printed circuit board as shown. Grounding either lead is what controls channel 4 or 5! Channel 3 is a fully proportional channel that goes left, neutral or right. Channels 4 and 5 are neutral and one direction only.

[danielhr77]

He must have not had the 5th channel servo plugged in and assumed that there was no channel switch connections available?

Right!!! At the time I didn't test the 5th channel and after reading what PeterV wrote on this thread, I understood how the 5th channel worked on the new 2.4Ghz Summit...

Check this video I made after I did this mod... It shows how the 4th and 5th channel work as you said...

[EMAXX ab USER]

ok cool! I get it now. Its just that when I played with the 4 and 5 channels I was using 2 pole switches and was getting some funny results.

[digi]

I just checked mine that came with my Rustler about a month ago (serial# A0006969), and it will only blink 4 times, after that it goes back around to 1 blink. Should I still be able to mod it for 4 channels?

Can anyone give me any info on this? Does anyone know what it means to only blink 4 times instead of 5? I took a peak inside and the PCB is identical to the pictures in the first post, with the 4 blank solder tabs, so if I could atleast get 4 channels I would be happy. Thanks.