Steering wheel button. Help.

Hi everyone.

This is the new proyect and i think i might need some help with it because i am new in electronics, i know the basics and can work my way around with the appropiate guidance.

So with that said here it is.

I want to place a button behind the steering wheel of my car that can control a relay, this relay will turn on some roof lights, like a jeep´s lighting bar. I have noticed a couple of things in the research i have done. This usually is acomplished by routing the cables trough the steering wheel and trough the steering column and then to the relay. But i spoke to the guys at my mechanics shop and told me not to play with that because of the air bag.... I didn´t understand very well how can this affect the air bag, or if it was dangerous but they told me not to do it like that because of the possible malfunction or danger of injury while installing-using it, and the more serious one, the voidance of the car´s warranty
So after that piece of advice i came up with the idea of doing a wireless button.

But this is sort of challenging because of a number of factors.

1.- I understand wireless can be infrared, radio transmition or bluetooth, but i just need advice on what to choose, and how to get started buecause i have never done wireless.
As the steering wheel.... well steers, i think the infrared is not an option here, or is it? What do you think would be better, of course this will be a short range pushbutton, i dont need power for 50 yards.... yet....(lol, just kiddin).
And radio frecuency, could someone tell me if this can affect the functioning of any equipment in the car?

2.- How to power the device. The recevier can be powered easily with the car´s 12v power, but the transmiter (button), i was thinking a small battery but i dont know if anyone has a better idea.

3.- What components you recommend, i am actually in Mexico, and electronic shops aren´t as well stocked as in other countries, so if you think of something i could get on ebay that will be just amazing. I am fan of Atmega8 so i have a couple of them here avialable, and do a little programming, just the basics but i am very interested in learning more and surely this will help.

I appreciate your interest and will be very thankful if anyone could guide me in this hands on the wheel lighting proyect.

Thanks for reading/helping.

Why not just put a switch on your dash. No need to mess with the steering wheel.

Well, it is always an option. But it is more interesting if it is always at finger reach, and you dont have to take your hands off the wheel.

And its a good proyect for learning something about wireless don´t you think?

A wireless switch may sound neat, but it does not sound very practical. A switch in the dash is easy and cheap. A wireless switch is not cheap and not so easy. If you want to learn wireless, make it an indoor project

Have you ever disassembled a steering wheel from a modern car with airbags? I suggest you go to a junk yard and see what entails. The airbags are usually deployed from the wreck that put the car in the junk yard, so there is no risk of unexpectedly activating them.

You will find the column is hollow, but there is a device that allows the wheel to turn without twisting the wires going to control buttons on it and to the airbag. On a Honda, you could substitute functions for one of the buttons, but it would be quite a bit more difficult to pull an additional wire.

If your car doesn't have every attachment available, the device may have an extra circuit or two. Honda calls it a reel; other manufacturers may call it something else. The Honda reel does not have sliding contacts. Inside the reel is more like a half open tape measure with the wires in a ribbon that replaces the tape. The spiral loosens and tightens as the wheel rotates.

John

rene_a133 said:

...i spoke to the guys at my mechanics shop and told me not to play with that because of the air bag.... I didn´t understand very well how can this affect the air bag, or if it was dangerous but they told me not to do it like that because of the possible malfunction or danger of injury while installing-using it...

Click to expand...

And with good reason...take that advice. It would not be a good idea to add ANYTHING that has the potential to induce a voltage in the squib wiring. The technicians are even instructed to keep diagnostic equipment away from airbags. At one Ford Training Centre, a trainee left the diag tool hanging on the steering wheel (using the handle which was designed for this) during a lunch break. Upon returning to the workshop after lunch, the diag tool was found on the workshop floor, having been ejected through the rear window. It was assumed that the diag tool fan kicked in and this was enough to deploy the airbag.

GM have also instructed all dealers to remove a fold-out bracket, which allows their Tech2 diag tool to be hung in a similar fashion. There may also be similar instructions from other manufacturers....

jpanhalt said:

...You will find the column is hollow, but there is a device that allows the wheel to turn without twisting the wires going to control buttons on it and to the airbag. On a Honda, you could substitute functions for one of the buttons, but it would be quite a bit more difficult to pull an additional wire.

If your car doesn't have every attachment available, the device may have an extra circuit or two. Honda calls it a reel; other manufacturers may call it something else. The Honda reel does not have sliding contacts. Inside the reel is more like a half open tape measure with the wires in a ribbon that replaces the tape. The spiral loosens and tightens as the wheel rotates.

John

Click to expand...

There are some generic names for this component - "Clock-spring", "Rotary-Coupling", "Squib-Contact" to name a few, but they generally work in the way described by John. There are numerous copper traces sandwiched between an insulating material, in a ribbon fashion. Two of the traces are for the squib in a single-stage airbag, and four for a dual-stage airbag. The remainder are for the horn and I.C.E. (In Car Entertainment) controls. Since the ribbon can only carry so many conductors before becoming too bulky, the horn/ICE controls generally use a resistor ladder. Some manufacturers are currently experiencing problems due to degraded connections, and pressing a certain button does not have the desired effect - pressing the horn should not make the radio volume increase.

Thanks for the interest. So i think messing with the steering wheel is not the best of ideas.
Been to a junkyard told the idea, look around some airbags, get the same warnings as in the mechanics shop. Now is an option to take a wire without introducing it in the steering wheel, i will think about that, but the wireless sounds so great (and challenging).

What do you think of the wireless button idea? Is it possible?

Does your steering wheel have the horn button built into it ?

You could contruct a device that measures the length of the press of the horn button. Less than 0.5 seconds for example toggles the flashing lights, more than 0.5 seconds gets ignored.

picbits said:

Does your steering wheel have the horn button built into it ?

You could contruct a device that measures the length of the press of the horn button. Less than 0.5 seconds for example toggles the flashing lights, more than 0.5 seconds gets ignored.

Click to expand...

Just don't turn on your lights with the horn in the wrong neighborhood...

so u have a deathwish

I do SRS System Replacements for a living so let me give you some advice Do Not mess with the Steering Wheel are any of the components atached to it the least of your problems would be that mabye your horn might not work if you screw with the clockspring the worst would be a deployment of the airbag while you were driving the car.
Also if by some miracle you didnt crash if the bag was to deploy it is going to cost you a lot of money to have your srs system repaired and the damaged componets replaced. and dont bother trying to get your insurance to cover the damages cause they wont. put a switch in the dash in a safe location and be done with it.

Hmmm, Keep switch in dash I would. Only then will you not feel the force of airbag...

**broken link removed**

lol.

Thanks for the advice. Now I will not mess with the steering wheel, because i dont want to be in youtube most viewed accidents nor in the hospital.

Yoda or someone experienced in car systems: Do you know if an radio frequency or other type of wireless device can activate the airbag?

Anyway i think this is getting to complicated, maybe it will be in the dash while earning experience on the field but continuing with the learning, could someone guide me to good learning material on wireless (preffered online)?

Thanks for the interest guys.

Man, even without thinking on the electronic system itself:

1)Making place for the coils, IR leds or whatever you use, plus the batteries, buttons... takes a lot of space! You have ---at least--- to use SMT components to keep it at a decent size (do you have them?)

2) think in the Aesthetics too. How are you going to stick it to the steering? Duct tape? (Just kidding, I bet you didn't thought about that yet).

3) Your control must remain in place when the airbag is deployed (i.e. not flying together with the airbag cover, or hiting your head as a bullet). That rule bans majority of locations along the steering circunference.

4) Did I mention that the system must not interfere with your hands when turning the wheel?

As a result, the best place to put the thing is maybe at the lower point of the steering, close to your legs. This is ridiculous,

I would prefer to re-wire the small stick that comes at the left side of the wheel, the same that turns on the high headlights when pulled towards you

One hole, one toggle switch and your done. Wireless switch is just silly.

what u can do is remove the cover that's right behind ur steering wheel, (it pops off as it's held on with clips)
once in there u can put ur switch in facing up. by cutting a hole in the cover that u removed.
then run the wires straight down behind the dash.
this will be easy and will work because this part does not turn with the steering wheel from there on it's simple.

good luck!!

Nate,

ps. I've recently done this to a 2007 honda (I had to get to the horn wire so that I can manipulate it to work with a smart siren (switch ing between horn and siren)

rene_a133 said:

Well, it is always an option. But it is more interesting if it is always at finger reach, and you dont have to take your hands off the wheel.

Click to expand...

How about a foot switch? Go back to your local junk yard and look for an older vehical with a foot operated high beam switch. That would work well.

Andy1845c said:

How about a foot switch? Go back to your local junk yard and look for an older vehical with a foot operated high beam switch. That would work well.

Click to expand...

yeah thats a good plan,

they definatly have something made for it as the police scooters have the switch to change their headlights from regular to high beams on the floor next to the drivers right foot.

here's some you might want to look at,
Foot Switches Overview

this one comes in momentaily or maintained action so it might be just right for you,

Good luck!

Nate,

dont worry i will help u in this issue using simple components with out scraping the steering wheel

we will make this one using RADIO FREQUENCY dont bouther, it is very simple, follow the steps
we will make use of commercial electronic parts for reaching our goal.

first of all u want to purchase the following:
1. low cost wireless mic (in india it is 60-80 rupees) operated with AA battery
2. one FM receiver board(in india it is 45-80 rupees) it operates with car battery
3. make one 555 timer IC based astable multivibrator with any frequency around 1-KHz
4. one mono stable multivibrator with the time pulse of more than.01 sec
5. buy a electromagnetic relay of ur working voltage


now pluck off the wireless mic's microphone and connect the output of the 1KHz astable 555 circuit to the wireless mic circuit instead of microphone. now make a common supply for both 555 and wireless mic and connect it to a AA battery through a push to on and push to off switch the switch costs Rs 8 INR. now case the circuit using cardboard or some casing with switch outside, using a parcle tape or double side adhesive glue it under the steeering wheel, Tx circuit is finished.

now coming to receiver u make a 555 monostable with a delay of .01sec, and the output of the 555 i.e 3rd pin to relay and from relay to appliance. now the input to trigger pin of the 555 shoud be from the radio receiver(FM receiver) audio output. now set some threshold to trigger using a voltage devider to trigger pin

finished u now designed the Tx and Rx circuits.


we can do this still better by using a flip-flop in receiver side and by replacing a push button at the Tx to reduce continuous drain of current.