Go Back   RCCrawler Forums > RCCrawler General Tech > Electronics
Loading

Notices

Thread: My TQ5 5 channel pistol project has begun

Reply
 
LinkBack Thread Tools Display Modes
Old 04-11-2010, 04:34 PM   #1
Quarry Creeper
 
Join Date: Jan 2010
Location: USA
Posts: 402
Default My TQ5 5 channel pistol project has begun

My other hobby is electronics and I am participating in the DesignStellaris 2010 contest. The goal is to create something useful out of a particular Stellaris ARM Cortex M3 microcontroller. I am sure you don't care about the details of that, but you may be interested in my project.

I am modifying a new Traxxas Link HO TQ4 2.4GHz radio. We all know that it is a great radio for a Summit (I have another one for that too), but the extra channels don't quite fit the Crawler world because of the lack of positions and end points. Using a protocal analyzer, I have found out how to gain control of channels 3, 4, and 5 (along with 1 and 2 of course).

My most basic goal is to add three 3-position switches with adjustable end points and add an very basic LCD character display. If that goes well, I would like to add mixing for dual esc and mixing or direct control for rear steering as needed (while still having an addition 3-position channel). I haven't decided if I should bypass the factory multifunction knob and leave the steering and throttle basic for now.

I have ordered a bunch of buttons and switches which I will add as I define the functionality of my TQ5. I think it will be a fun project. The project submission is due in June, so my prototype should be ready by then.

Last edited by wantAsummit; 04-25-2010 at 12:42 PM.
wantAsummit is offline   Reply With Quote
Sponsored Links
Old 04-11-2010, 08:16 PM   #2
Rock Crawler
 
Join Date: Mar 2010
Location: Hampton
Posts: 751
Default

i am sure if you add the dual esc mixing capability to it you will have the attention of many. sounds like it could even be the answer for some of the super class guys. keep the posts coming.
Grimreeper is offline   Reply With Quote
Old 04-12-2010, 10:39 AM   #3
Got Worms?
 
Join Date: Jun 2009
Location: Golden, CO
Posts: 6,116
Default

how do you plan on mixing channels, electronicly, or hard wiring them
losikid is offline   Reply With Quote
Old 04-12-2010, 01:34 PM   #4
Quarry Creeper
 
Join Date: Jan 2010
Location: USA
Posts: 402
Default

I would do the mixing electronically. I am open to suggestions for how to implement them, but I would prefer to stick with basic needs and stay away from odd/rare scenarios. I would add smarts to the software to help make it easy on the user. For what it is worth, I have switches, buttons, potentiometers, and encoder knobs on order. How best to use them? I don't know yet. Most people seem to be looking for a radio with a single 3-pos 3rd channel. This is why my initial goal was going to be three 3-pos additional channels and build up from there. Unfortunately with the new TQ Link controllers, there aren't many free/easy modifications. I just felt like jumping to the next level and adding a microcontroller, circuit board, etc... for my project.
wantAsummit is offline   Reply With Quote
Old 04-12-2010, 02:49 PM   #5
Got Worms?
 
Join Date: Jun 2009
Location: Golden, CO
Posts: 6,116
Default

well when you say for dual esc, you'll need a electronic controller that will be able to mix, front only and rear only channel all to the trigger. for a dual esc radio, i'm doing a similiar build so i'm interesyed how your will turn out, how will you get 5 channels out of a 4 channel radio
losikid is offline   Reply With Quote
Old 04-12-2010, 03:25 PM   #6
Quarry Creeper
 
Join Date: Jan 2010
Location: USA
Posts: 402
Default

My software shouldn't have a problem with the electronic mixing. The issue will be deciding how best to gain functionality over the mixing with switches/knobs. Maybe a 3-pos switch would be fine to implement front and rear dig with dual ESCs. Maybe there could be a knob for variable mixing if it is desireable.

As for getting 5 channels out of a 4 channel radio: The TQ4 was meant for a summit. CH1 = steering (dual servo plugs for this), CH2 = Throttle, CH3 = 2-pos for the transmission high/low gear selection, CH4 = 3-pos for diff lock (none/front/front+rear). The way the new link version of the TQ4 implements CH4 is by using outputs on both CH4 and CH5 for the front and rear diff lock servos (it is a 5 channel receiver).

I expect my project will be in prototype form for quite some time! In the end, I intend to make a custom circuit board for it.
wantAsummit is offline   Reply With Quote
Old 04-12-2010, 03:43 PM   #7
I wanna be Dave
 
Join Date: Oct 2008
Location: Golden
Posts: 2,588
Default

watching this thread, I'm building a 6ch TQ but using an airplane radio motherboard.
monkeyracer is offline   Reply With Quote
Old 04-12-2010, 04:00 PM   #8
Quarry Creeper
 
Join Date: Jan 2010
Location: USA
Posts: 402
Default

Quote:
Originally Posted by monkeyracer View Post
watching this thread, I'm building a 6ch TQ but using an airplane radio motherboard.
Not a bad idea. I am sure that is its own sort of challenge. At least you will have what you want in the end! I love the creativity on this board.
wantAsummit is offline   Reply With Quote
Old 04-12-2010, 04:10 PM   #9
Got Worms?
 
Join Date: Jun 2009
Location: Golden, CO
Posts: 6,116
Default

Quote:
Originally Posted by monkeyracer View Post
watching this thread, I'm building a 6ch TQ but using an airplane radio motherboard.
Yea, me and monkey racer are essentially trying to accomplish the same thing with a turborix 6 channel radio,


but i'm interested in your build

mostly in making a programmable circuit board that makes a switch for the dual esc's, it can be done by hardwiring but it takes alot of components to get everything trimmed out just perfect. I'll be watching this thread and see how it turns out. Good luck

Subscribed
losikid is offline   Reply With Quote
Old 04-19-2010, 12:30 PM   #10
Quarry Creeper
 
Join Date: Jan 2010
Location: USA
Posts: 402
Default

OK, I got my pile of switches in the mail and have been trying to decide what makes sense.

1) I have a 4-direction tactile switch plus center pushbutton which I could use for setup operations such as end points, etc.

2) I have a 12 character/line, 2 line display which I could use to display end points, etc. during setup. This would go on the flat section of the controller at the bottom, next to the grip facing up.

3) I have some encoder knobs with center pushbutton which can be used as endless potentiometers or multiposition knobs. My microcontroller can support 2 of these.

4) I have a few 3-position toggle switches both of the momentary (on)-off-(on) and toggle type on-off-on.

5) various styles of momentary push buttons, tactile and not.

6) This is the one that excites me the most and where I see the most potential for the MOA and dual steering crowd: I have a mini analog joystick with center pushbutton. I gave it a test fit and it can go right where the standard 2-position red thumb switch normally is on the TQ radios. In a dual ESC scenario, the up/down direction could be used for proportional dig on-the-fly. At the center both ESCs would act the same. Push up the joystick up for proportional front dig. Push the joystick down for proportional rear dig. The same type of thing can happen for the steering with the left/right direction. 1 option is independent control of rear steering. Another is proportional steering mix on-the-fly. At the center, front steering only. Push the joystick right and proportionally add mirror-image-style rear steer mix. Push the joystick left and proportionally add crab-style rear steer mix. This can add a lot of functionality using your thumb in its natural transmitter holding postion.

Let me know what you think (I don't have a MOA or rear-steer crawler), but I am confident I can generate a lot of functionality with relatively few controls. The big issue that I will need to overcome is how to assign functionality for all the different scenarios.

Last edited by wantAsummit; 04-19-2010 at 12:33 PM.
wantAsummit is offline   Reply With Quote
Old 04-19-2010, 04:44 PM   #11
Got Worms?
 
Join Date: Jun 2009
Location: Golden, CO
Posts: 6,116
Default

how will up give you front and down give you rear dig that is proportional, also what micro controller are you using, and an avg person program it and set it up for this ??
losikid is offline   Reply With Quote
Old 04-19-2010, 07:40 PM   #12
Quarry Creeper
 
Join Date: Jan 2010
Location: USA
Posts: 402
Default

Quote:
Originally Posted by losikid View Post
how will up give you front and down give you rear dig that is proportional
With the joystick at the center, both ESCs would be driven equally from the throttle trigger. At either end of the joystick travel, either the front or rear ESC would remain at neutral (true front or rear dig). Anything in between would be proportional. For example, if the joystick was pressed 25% up, the front ESC would respond normally to the throttle trigger while the rear ESC responds with a 25% reduction in speed. This would continue 50% joystick = 50% reduction in rear ESC, 75% joystick = 75% reduction in ESC, 100% = 100% reduction in ESC (again, true dig). The opposite would be true for pressing the joystick in the down direction. This seems to achieve what the dual-stick guys can do, but with some controlled precision. Any thoughts on this (would it be useful)?

Quote:
Originally Posted by losikid View Post
also what micro controller are you using, and an avg person program it and set it up for this ??
Here is a link to the DesignStellaris contest for anyone who is interested: http://www.circuitcellar.com/designstellaris2010/
wantAsummit is offline   Reply With Quote
Old 04-19-2010, 07:50 PM   #13
Got Worms?
 
Join Date: Jun 2009
Location: Golden, CO
Posts: 6,116
Default

How big is this joystick to give you you that precise of control
losikid is offline   Reply With Quote
Old 04-20-2010, 05:47 AM   #14
Quarry Creeper
 
Join Date: Jan 2010
Location: USA
Posts: 402
Default

Quote:
Originally Posted by losikid View Post
How big is this joystick to give you you that precise of control
The joystick is actually very small and can be adjusted with just your thumb if I leave it in the grip.

The precision I was referring to was a two-stick vs. mixing comment. With 2 sticks it is easy to achieve different wheel speeds front to back, but I can only assume that it is more difficult to achieve equal wheel speeds front to back (please correct me if I am wrong). What I proposed would have equal wheel speeds by default with the ability to adjust away from that on-the-fly.
wantAsummit is offline   Reply With Quote
Old 04-20-2010, 08:07 AM   #15
Got Worms?
 
Join Date: Jun 2009
Location: Golden, CO
Posts: 6,116
Default

yea, i understand what your trying to do, me and monkeyracer are attempting to achive this idea too. But that lttle joystick probably has 1/4" movement from center, and trying to precisly get around 25%, 50%, or any XX%. And on a stick all you do is mix the two channels and one stick controls both front and rear, flip the mix switch and one stick is front and one is rear.
losikid is offline   Reply With Quote
Old 04-20-2010, 10:46 AM   #16
I wanna be Dave
 
toy4crawlin's Avatar
 
Join Date: Feb 2006
Location: Campbell, CA 4 hrs 2Rubicon !
Posts: 2,044
Default

Welcome to the 2.4mhz 5-6ch pistol club
Your joystick idea is interesting, not sure how to comment as it's difficult to picture what you have, but I think it's a cool idea.
What other rc's do you plan to run on it ?
toy4crawlin is offline   Reply With Quote
Old 04-20-2010, 11:42 AM   #17
Got Worms?
 
Join Date: Jun 2009
Location: Golden, CO
Posts: 6,116
Default

Quote:
Originally Posted by toy4crawlin View Post
Welcome to the 2.4mhz 5-6ch pistol club
Your joystick idea is interesting, not sure how to comment as it's difficult to picture what you have, but I think it's a cool idea.
What other rc's do you plan to run on it ?
I think what the idea is to have the joy stick

all the way up is full front no rear

All the way down is full rear no front

Center is full rear full front

Inbetween center and all the way up will limit the amount to the rear and full front

Inbetween center and all the way down will limit the amount to the front while the rear has full throw

This defitanly can't be done with hard wiring, its gonna have to be programmed somehow,

If i didn't explain it right please correct me
losikid is offline   Reply With Quote
Old 04-20-2010, 01:28 PM   #18
I wanna be Dave
 
toy4crawlin's Avatar
 
Join Date: Feb 2006
Location: Campbell, CA 4 hrs 2Rubicon !
Posts: 2,044
Default

oh that is very clear. sorry
so then the toggle has many specific positions.?
toy4crawlin is offline   Reply With Quote
Old 04-20-2010, 03:57 PM   #19
Quarry Creeper
 
Join Date: Jan 2010
Location: USA
Posts: 402
Default

Quote:
Originally Posted by losikid View Post
But that lttle joystick probably has 1/4" movement from center
I'll try to get a picture up in a day or so. I think the travel is just related to the tip that I put on it.

Quote:
Originally Posted by losikid View Post
on a stick all you do is mix the two channels and one stick controls both front and rear, flip the mix switch and one stick is front and one is rear.
Thanks, that clears up the attraction of the stick approach for me. I think this functionality could come close if I do it right.


Also, I was re-thinking the steering. I could have a 3 position toggle. Position 1 would be mirror-image mix (steering wheel only), position 2 would be full independant control (steering wheel front, joystick rear), and position 3 would be crabwalk mix (steering wheel only). The mix ratio could be set from one of my encoder knobs if needed.
wantAsummit is offline   Reply With Quote
Old 04-20-2010, 04:04 PM   #20
Quarry Creeper
 
Join Date: Jan 2010
Location: USA
Posts: 402
Default

Quote:
Originally Posted by toy4crawlin View Post
oh that is very clear. sorry
so then the toggle has many specific positions.?
losikid was absolutely correct about the functionality.

The joystick is analog with potentiometers in the X and Y directions (just like a stick radio)

I have a LCC and a summit which could benefit from this radio at the moment. I just want my project to be able to cover any future situations. I don't have anything with dual ESC or rear steer yet, so that is why I have been looking for advice on how other would like to have control over it if they had a choice.
wantAsummit is offline   Reply With Quote
Reply



Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 05:29 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO ©2011, Crawlability, Inc.
Copyright 2004-2014 RCCrawler.com