The true extent of my Madness……

[ph2t]

We’ll I’ve finally finished the #$%@&* !!

You can view the circuit as a PDF file here.

time to sleep…………………

ph2t.

[Shypo]

that makes no sense to me.. what is it lol:blush:

—-
Go Fast, Be Free with Low CC

Undisputed Post Pimp

[Crom]

Ph2t, Is this the schematic for your proportional controller? Speed and direction? Wow… (I can barely understand it… :p)

You’ve got a working model?

---

The impossible just takes a little longer

[jamiekulhanek]

ph2t, your circuit looks good, like the idea of using optocouplers to isolate it. I am wondering, would it bother you if i made one of these for myself, using your design?

If life is a waste of time, and time is a waste of life, then let’s get wasted and have the time of our lives!!

[ph2t]

Jamie, go for it man! :smiley16: I’m more than happy to help, you can get all the parts from either Jaycar or Dick Smith Electronics. I’d like to keep the main development still here at tinyrc. It’s just easier to maintain that way.

Crom, yes this is it. when I get the time over the next day or two I’ll write down a detailed explanation of how it works. Although the principal is explained in detail in the original thread. This thread includes video and pictures of a very messy prototype. Give me a few weeks to get one lookin tasty…

yo Shypo (you pimp! :smiley2:), this is my proportional controller emulator. It provides very good speed control (fwd and rev) and not-to-shabby steering control. The steering is good for really slight turns and varying arcs, also times for when your thumbs just can’t hack it!

The goal is to get it into a pistol-grip like controller. I can then piggy back whatever Freq controller I want to it and take it from there.

[jamiekulhanek]

Ahhh so the proportional steering kinda works??? Thats good, just wondering if u are gonna further the design and put it onto a pcb???

And, have you built and tested it yet, or is taht just a hypothesis of how it will work.

Thanks Ph2t, you truly are a bit pioneer.

If life is a waste of time, and time is a waste of life, then let’s get wasted and have the time of our lives!!

[ph2t]

Yes I have built this and it does work. I have video of the speed control in action in the tinyrc thread. I tested the steering as well and it works too(although I don’t have video of this). I used the opto-couplers and this improved the control to the steering. I have bought some veroboard to put the whole thing together and get away from the birdsnet I’ve created.:approve:

I’m moving house at the ‘mo so development is sort on hiatus until next week.

ph2t.

[jamiekulhanek]

Very impressive, id like to know a bit more about it.

Firstly, with the throttle, does it only control the car in the forward direction, or does it have neutral, forward and reverse?? e.g. i mean when the pot is centred, is it neutral?

And also with the steering?

If life is a waste of time, and time is a waste of life, then let’s get wasted and have the time of our lives!!

[ph2t]

The throttle is proportional in both directions(Fwd & Rev).

When the pot is centred there is no signal (the trimpots R13/R15 are used to tweak the centre position for no signal). This is the same for the steering (in this case the trimpots R21/R29 are used to calibrate the centre, neutral position).

Looking at the schematic I will explain it in portions.

1) Triangle wave generator:

U1B & U1C (parts of the LM324 quad op-amp) form a triangle wave oscillator at a certain freq. This part drives the throttle so its freq is about 30-40Hz (I think). This can be set by capacitor C1.

U2B & U2C are a copy of the same osc, but in this case the value of the cap C2 is greater for a lower freq. This drives the steering, I found the steering more responsive at a lower freq (approx 6 – 10Hz)

U1A is just a reference voltage source @ 3V. This is needed because op-amps usually are run off +ve and -ve voltage sources.

2) Comparator / Pulse Width Modulator

U1D & U2A take the signal from the output of U1C and compare it against a voltage level set by the potentiometer R12. I won’t go into too much detail here but when the voltage reaches a certain level @ the -ve input of U1D & U2A it outputs a positive voltage. (Bugger, this is hard to explain:dead:. I might need to draw some pictures) This is why a triangle wave generator is used. As you turn the pot R12 it varies the width of the pulse seen at the output. Hence the name “pulse width” modulator.

The daul-gang pot (R12/R25) is the part that makes it all happen. You will see that each side of the pot is wired in opposite direction. ie: I turn the pot one way causes one voltage level to increase and the other to decrease. It is this that gives you both directions.

3) Output stage

The outputs of U1D & U2A both drive the opto-couplers which then in turn drives the transistor allowing for the pin for the TX2 chip on the controller to go to ground. At first I didn’t have the opto-couplers and I was finding it hard to “pull” these pins to ground properly.

Stages 2 & 3 are duplicated for steering AND throttle. It is really stage 1 that differs (and then only in the value of caps C1 & C2).

Sorry for such a braindump, but you asked :smiley2:.
I’m just waiting for uA to get back from his holiday so he can read this!:)

ph2t.

[PandaBear]

wow 😯

(speechless)

[ph2t]

Thanks 😀

But we should wait till tha fat lady sings….

ph2t.

Edited by – ph2t on 27 March 2003 15:17:06

[Efarel]

Hi,
greetings from Italy !

You are GREAT

Thank you for your effort, it is my next bit char project in the pipe !
Have you considered the big revolution of your project ??? I’ll buy a Auldey or Tokoros non proportionale 1:32, dial in your mighty prop emulator and I’ll have a wanna be mini z palm runner for 1/10 of the palm runner’s cost.
AMAZING
😀

Efarel

[jamiekulhanek]

Yeah my idea used dual gang pots, cause i had no idea how to make a single pot work. I have an idea about electronics and found that very easy to follow. Im glad that the throttle frequency is fairly high (even though ‘BIG’ r/c uses upto a few kHz), should give a smoother throttle response.

I have completely ditched my attempt at a proportional bit, cause i think your idea is far better.

If life is a waste of time, and time is a waste of life, then let’s get wasted and have the time of our lives!!

[ph2t]

Yeah the throttle frequency can be changed, and to tell you the truth it could probably be increased. I haven’t tried this yet and I don’t know how high you could go until the signal just drops out. Keep in mind that these controllers use an OOK (On – Off Keying) transmission scheme to encode exactly what it wants the car to do. If the freq is upped too much, it might negate this OOK scheme to crap. The steering once in production will look kinda jerky. It’s like tapping the L-R buttons frequently to get a slight turn instead of a full turn which is just holding the L or R button down fully. Unfortunately nothing can be done about this since the steering is magnetic. I’ll pull my finger out of my arse and do some video once we move on the weekend.

The way to calibrate the controller is to centre the pot (be it steering or throttle) and then adjust the trimpots until there is no signal for both L/R or Fwd/Rev. You then turn the pot just slightly and adjust the trim until the signal starts working. The values of the other resistors ensure that turning the pot to the extent of its arc will result in a full “ON” signal going to the controller. (The same as pressing the button fully)

When used on a daul bat bit, this controller is even better. I can start off the mark without any wheelies at a lower speed and then gain full speed for some real action.

Hey Efarel, thanks for the praise :), but you might want to check the circuit on the controller of the Auldey to make sure that the pressing of the button on the controller equates to the same action as bringing the pin to ground. Although with the use of the 4N25 opto-couplers you could pretty much substitue these pins (5 & 4 on the 4N25) for the push button. Just make sure that the polarity is correct because the light dependant transistor in the 4N25 will only allow current to travel from Pin 5 through to 4 (being an NPN transistor and all…) You can ignore pin 6, it’s not needed.

Again, here are the videos of my testing.

test1
test2
test3
test4

ph2t.

[Admin]

@ph2t
Your idea sound’s great, but there is some big problems. In the pic’s i’ve seen that you are using a car with an TX2-RX2 transmitter/receiver combination. The signal coding is quite simple, the number of transmitted pulses decode the required function in the car. You can find a PDF with the complete description at http://www.bit-racing.de/Tuning/TX-2RX-2.pdf

For the function RIGHT (the one with the longest code) you need 81 ms for the complete transmission. So a maximum of 12 Hz is possible. That is the reason for one of the problems you encountered. The other problem is that the transmission time depends upon the function. If you drive only forward, it will work. But if you drive around a race track, i am sure it won’t. Timing problems.

Try getting a car with the new TX6/RX6 transmitter/receiver combination. They use a different en-/decoding, with equal transmission time for all functions.

cu diets

ps
We (the member’s of a german forum) encountered the same problems. If you understand german or if you know someone who can translate it, this link might be useful.
http://549.rapidforum.com/topic=100385700661

[ph2t]

diets, wow! you have opened up another stage of development for me. I have tested steering by itself and throttle buy itself. But not together! hmm……….

Efarel and Jamie, please let me know how you guys go with this.

ph2t.

[jamiekulhanek]

Well im not guna build it till this prototype is fully functional. Just wondering if the clone TX chip is the same as the BCG one???

If life is a waste of time, and time is a waste of life, then let’s get wasted and have the time of our lives!!

[ph2t]

The Bensu clone I developed this on uses the TX2/RX2 chipsets…. (first revision B)

Just moved house so I have to unpack all my stuff to start checking this……..

ph2t.

[Shypo]

hurry up ph2t lol. i wanna c it

—-
Go Fast, Be Free with Low CC

Undisputed Post Pimp

[ph2t]

shypo, you’re a smart arse pimp mutha! lol! :D:D

[Shypo]

yeah i know. it made me who i am lol

—-
Go Fast, Be Free with Low CC

Undisputed Post Pimp

[z-beam]

yep c’mon ph2t.

any xplanation of your tag?
z-beam, an almalgamation of the awesome “z” nissan cars and my euro favorite the bmw. also a sick movie with samuel l jackson called the cave mans valentine has a rantin dreaded up sammy rantin ” i see your z-beams”

[ph2t]

$#^%@ !!!

👿

Anymore of this and there will be some serious blackeye:blackeye:blackeye:blackeye:blackeye:

😀

ph2t.

[z-beam]

no pressure… ph2t, do you reckon the new super-g’s extra button could be simulated gears? like in f1, left shift down?, right shifts up???

possible i think yes, tomy pulling out all fingers? probably not… what do you reckon?

[ph2t]

Who knows dude, gotta see what chipset these buggers use. It all depends on the amount of channels available to do stuff……

ph2t.

[Efarel]

Hi Ph2t,
I just built the first stage, the throttle Lm324 is up and working.
To be honest, I just checked it in a straight line and it works very well.
I’ll use a Bit Char – F controller (F for Frankestein !):
forward throttle with LM324 propo emulator,
steering and reverse still in digital.

I’ll try to gather enough data to help you with the coding signal problem.
GO Ph2t !
Ciao
Efarel

[Shypo]

i wanna c this thing in Motion c’mon ppl!!

—-
Go Fast, Be Free with Low CC

Undisputed Post Pimp

[ekwj]

haha lost!! dunno what u guys are talking bout!

The sky is the limit! |ekR34|

[ph2t]

ekwj: I’m trying to build a proportional controller for these mad little cars. Including variable throttle and sorta proportional steering.

ph2t.

[ekwj]

too technical 😀

The sky is the limit! |ekR34| http://www.ekr34.tk

[ph2t]

That’s why it’s soooooooo mad!:smiley2:

ph2t.

[ekwj]

so how’s the project goin so far?

The sky is the limit! |ekR34| http://www.ekr34.tk

[ph2t]

Got 25 people coming over for dinner tonight, and we’re still cleaning the bloody new house since we move 2 weeks ago. I guess you could say that it ain’t at the ‘mo .

ph2t.

[Crom]

*lol* Couldn’t you just get Shams to build it? Or clean you house or something? Thats what little brothers in law are for aren’t they?:smiley2:

---

The impossible just takes a little longer

[ph2t]

hahahaha! That’s a good one Crom. With the amount of free pc support the bugger gets from me you’d think so.

Funny you mention this since just tonight my wifes family was over for dinner and Shams gave me a hand cleaning up. Such a good little robot!:approve:

For anyone wondering wtf, Crom goes to uni with my bro-in-law….

ph2t.

[micro_Amps]

small world hey:approve:

[ph2t]

Been doin a bit of research to do with this timing problem that diets pointed out and have found some info that might help me get over this problem.

The pdf located here, was found on a website somewhere, I can’t remember where…… So I thank that person for doing all the ground work.:)

So to take this info futher and converting the timings in to a frequency we have the following:

Function_______________Cycle____________Max Freq
_______________________(ms)_____________(Hz)

Forward Only…………18…………..55
Reverse Only…………48…………..20
Left Only……………66…………..15
Right Only…………..74…………..13
Forward + Right………44…………..22
Forward+ Left………..38…………..26
Reverse +Right……….56…………..17
Reverse + Left……….62…………..16

So, given this data I guess the max frequncy I can run the PWM at and NOT cause conflicts is 13 Hz. I would then remove the triangle wave generator from the steering circuit and drive both circuits (Steering and Throttle) off the same oscillator. This would keep both circuits in time and not cause the conflicts.

Now I know what I will be doing this Easter Weekend. :approve: Just hope my theory isn’t full of crappola!:smiley2:

Edited by – ph2t on 17 April 2003 15:42:00

[micro_Amps]

Ph2t, go a bit higher with the frequency.
Sure “right only” and “left only” require 13Hz, but how often do you sit there and steer only?
The main ones you need to worry about are…
Fwd only
Rvrs only
Fwd & L , Fwd & R
Rvs & L , Rvs & R
These are the ones used while actually driving.
I have more ideas on this to make it feasible.
You need to keep the frequency as high as possible, but of course you know that.
Hopefully i will speak to you soon.
:)uA

[ph2t]

Here are some pics of my work in progress. I know it doesn’t mean much for people who don’t wear propellors on their heads, but it’s some info none the less…..:approve:

I just ran out of Solder, *arghhhhh*. I guess I know what I’m doing tommorrow, another trip to Jaycar……..

ph2t.

[jamiekulhanek]

Hmmm im building this project in electronics at the moment, ive got all the parts and im puting the design onto PCB, i am now totally confused whether this will work or not…..

If life is a waste of time, and time is a waste of life, then let’s get wasted and have the time of our lives!!

[ph2t]

It will work Jamie. For the minute just concentrate on building the first stage, throttle. Small steps……….

ph2t.

[jamiekulhanek]

Okay mate, ive got the throttle part of the circuit on the computer ready to convert onto PCB.
Ive got all the parts i need aswell.

If life is a waste of time, and time is a waste of life, then let’s get wasted and have the time of our lives!!

[ph2t]

Ahhh, good stuff man…. What do you use on the PC to design your ciruits? Does it do auto layout and stuff like that?

[jamiekulhanek]

Using the software, you put the design onto the computer, and press the pcb button, which automatically draws the PCB design, in many different layouts…..very handy.

If life is a waste of time, and time is a waste of life, then let’s get wasted and have the time of our lives!!

[ph2t]

What’s the name of the software?

[jamiekulhanek]

The software is called circuit maker.

You can download the program for free (student edition, but still does everything) at http://www.microcode.com/downloads/student.htm
It is quite easy to use, and as I said, it puts the design onto PCB.

If life is a waste of time, and time is a waste of life, then let’s get wasted and have the time of our lives!!

[ph2t]

Just a little note to say that this project is still happening, just not all that quickly. These are so many other projects that are smaller and quicker to do that this beast is taking a while……….

ph2t.

[jamiekulhanek]

Ph2t, i have completed the throttle section of this circuit, but it has only 2 speeds, flat out, and just ticking over. I have checked the circuit and made sure it is all right, but to no avail.
I am just wondering if you have changed any components or made a new schematic. Please helpo this is giving me the sh*ts.

[jamiekulhanek]

Ph2t, i have completed the throttle section of this circuit, but it has only 2 speeds, flat out, and just ticking over. I have checked the circuit and made sure it is all right, but to no avail.
I am just wondering if you have changed any components or made a new schematic. Please helpo this is giving me the sh*ts.

[ph2t]

Yeah it’s funny man, I got a similar response when I built it on veroboard. But on the bread board prototype it was OK. Try low values of the pots and see what that gives…. I haven’t changed any thing on the circuit. This is where I hit a brick wall as well. One day I’ll pull my finger out of my arse and continue with this mod……..

[ph2t]

Yeah it’s funny man, I got a similar response when I built it on veroboard. But on the bread board prototype it was OK. Try low values of the pots and see what that gives…. I haven’t changed any thing on the circuit. This is where I hit a brick wall as well. One day I’ll pull my finger out of my arse and continue with this mod……..

[jamiekulhanek]

What pots do you mean, the big ones or the trimpots? What should i change them to??

[jamiekulhanek]

What pots do you mean, the big ones or the trimpots? What should i change them to??

[ph2t]

The bigger daul gang ones. Try a lower value I guess, pick, use your skillz man..:D

Centre the dual gang pot first, then adjust the trimmer pots till you get no signal for either fwd or rev. Then move the dual gang pot each way and see the results. Adjust the trimmers then as required.

[ph2t]

The bigger daul gang ones. Try a lower value I guess, pick, use your skillz man..:D

Centre the dual gang pot first, then adjust the trimmer pots till you get no signal for either fwd or rev. Then move the dual gang pot each way and see the results. Adjust the trimmers then as required.

[jamiekulhanek]

Damn just my luck to hafta replace the $$ ones 🙁

So i guess a 1k pot would be my best bet, as a 10k job has crap resolution.

[jamiekulhanek]

Damn just my luck to hafta replace the $$ ones 🙁

So i guess a 1k pot would be my best bet, as a 10k job has crap resolution.

[ph2t]

Brutally said but true, 😀

[ph2t]

Brutally said but true, 😀

[ph2t]

The problem has to do with the fact that the voltage difference between zero and 100% duty is bugger all. I think (can’t remember) that the voltage varied between 1.2 -> 1.8V at the input of U1D and U2A. It needs a low resistor to get the sweep of accuray to control this small voltage difference.

[ph2t]

The problem has to do with the fact that the voltage difference between zero and 100% duty is bugger all. I think (can’t remember) that the voltage varied between 1.2 -> 1.8V at the input of U1D and U2A. It needs a low resistor to get the sweep of accuray to control this small voltage difference.

[merc-blue]

im reviving this. with a new design… ive done some circut simulations and it all looks good. works on the speed of pulses pretty much the same as this… ive set 1 week to get it working or im gonna scrach it … if ph2t and jamie (both done elet. eng corses then i cant a yr12 student)

[betty.k]

gotta pick you up on this merc. i never even completed yr10. a piece of paper with fancy numbers won’t design a curcuit:8ball:

[jamiekulhanek]

Your giving it a week?? Man you are impatient lol!

[merc-blue]

lol yeh i only got one design idea… actuly im giving it longer… im giving my one design idea a week… if it dont work im gonna get a epoch board and stuff and chuck it in a SS and say “look at my propo emu SS” AHAHAHAHAHA

[jamiekulhanek]

waste of an epoch board

[merc-blue]

theres not much else for them… epoches as they are arnt fast enough

[ph2t]

man, you really are busting out the skeletons. Good luck when you try to pulse Fwd with left or right. That’s where the issues start. See back a page for more info.

ph2t.

[Author]

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