coldturkey

The code Well im not going to include my source code for a few reasons but if anyone is interested I am happy to discuss. It took a fair bit of messing around. I really am pushing this micro to it's limits so a lot of braincells went into this, it really is more complicated then you think. The guts of it is: it continously monitors speed it continously drives the servo (drives it to zero when cruise is not selected). Then when cruise is selected it captures the current RPM as a reference and runs PI control (may add D later) to maintain the revs at the reference setpoint.

The installation: A couple of push button switches mounted under the steering column for the On/Off: An indicator LED to tell me it is on (also useful as an output for debugging) The base circuit (note this is before I added the 2nd Vreg): So this is what it looks like now, after debugging etc. Wires everywhere. Eventually it will live under the dash somewhere in that black plastic case.

The circuit: I had problems initially with the Servo sapping all the available power out of the voltage regulator when it moved, causing unpredictable shit. Im not really worried about the Servo not having all the power it needs, cause it still works sweet (3A should be plently). But I ended up moving the micro onto it's own Vreg which solved all my issues.

How do I turn it on/off and make it safe? Well the safety thing will probably spark different opinions (onions). The worst that can happen is that the accelerator locks on, which is really no different to a sticky cable. In theory your brakes should be powerful enough to overcome a stuck throttle anyway. The problem with servos are that when you cut the power they remain in the last position. Fortunately my accelerator springs are strong enough to pull it back to "zero" if you kill the power. The control is as follows: Turns on via an "on button" Turns off when either:the engine stops the clutch is pressed the brake is pressed the "off button" is pressed I also set up a kill switch, which kills the power to the servo and microcontroller, (but obviously then cant drive the servo back to "zero").

How do I modify the position of the throttle? The only way to do this on an old car (without fly by wire etc) is via some kind of motor. So I began playing with an RC servo to make sure I could control it to how I wanted it, with the intention of moving to a bigger servo eventually. Funny thing was, it actually worked really well and was able to pull the throttle without any issues. It's like a 13kg/cm servo so it is plenty grunty and if it dies then oh well it only cost like $18 bucks. Here is a vid of it setup pulling on the throttle with a string, dont worry I have since upgraded the string (it is now running a cable tie )

How do I get a continous speed measurement out of a car with no ECU? Righto, so it just happens to be that one of the pleasant chaps that owned this car before me installed an MSD ignition. Why is this important you ask? Well the MSD ignition has a 12V square wave tachometer output, i.e it gives a pulse every RPM. Funnily enough, if you take the gears and slipping clutch out of the equation, the RPM is proportional to the speed in a Manual Vehicle. And infact what I need is not to know what the speed is, but rather to keep it constant. If I can keep the rev's constant, then I can keep the speed constant. And because this thing only has 3 gears, you basically never change gear once you are up and moving. And under any situation I would want to "cruise" I would be in 3rd gear the whole time. So I began investigating with a microprocessor and got it reading the Revs!

Because I am a bit of a nerd I gave myself the challenge of designing and building it myself. Sure you can get kits, but they cost shitloads and to fit it to a car without an ECU, or other electronic gadgetry would be a lot of fucking about. Plus I wanted to be able to customize the algorithim that ran the control. Things needed working out: How do I get a continous speed measurement out of a car with no ECU? How do I modify the position of the throttle? How do I turn it on and off? How can I make it safe?

Well, i'd love to say theres been a lot going on interior/exterior/mechanical/anythingwise but I'd be lying. The winter months are pretty terrible down here for finding motivation to do anything outdoors, but there was one idea that I have been playing with for a while. Among my many weird qualities, I have this strange love affair with cruise control.... So a quick enquiry to the LVVTA: Ok brilliant, so aftermarket cruise control is not illegal, all I have to worry about is not putting the controls in silly places! Oh and it has to be installed properly and work properly. Err... ok.

If I remember back to my highschool drifter days... Theres a couple ways to do it. You can just unbolt the shifter off the side of the autobox and leave it connected and tucked up in your engine bay somewhere while switched to "park". To fix it permanently theres two wires to connect together on the plug that the inhibitor switch comes off. I cant remember which but it was fairly obvious and didn't take too long to sort out. I'd just leave the shifter thingy connected until you can work out which two wires are the magic ones.

Well thats all good, mine has seen better days and one of the threads inbetween the two main sections is stripped which makes things interesting. What area of auckland do you live in?

oh hell yes. How can you possibly have 3?? Any of them decent condition? I tell you what, I will be in Auckland 26th as we are flying through and staying the night at the ibis budget near the airport. If we could somehow organize getting one close to the airport before 10am on Saturday (27th) I could chuck it in my suitcase. I'm not sure how well that works for you but I could probably catch the airport express bus somewhere convienient for pickup.

Mr Richard. You mention you have crabs, you dont happen to have a spare single do you?

Just move down here. Your car will never overheat either. /spam

But what time are peoples flights in general cause if there's a bunch of people flying in after that time then 1pm isn't going to be very friendly for them as well as the people who are picking them up. It doesn't really matter for me cause will just leave in order to make it on time. Perhaps put up a poll?

Worry yourself not. Funnel prep is well under way.

I could be interested in some kind of tramp/hike cause I am supposed to be doing Tongariro later on in the year. Or instead I could carry on with my preparation involving the couch.

mmm I like that R34

well ok then

no

Yeah but you tend to want some fuel going in before you start cranking, not that cranking for a few extra secounds really matters but it might just annoy you more than anything when it seems like you car is hard to start. I have often wondered about the alternator charge signal, instead of the oil pressure switch. Any thoughts on this? (obviously you still need some kinda bypass for start up, but i'd think that the charge light is a more steady signal in most situations, except if your alternator died but meh you could have a bypass for that situation if you were worried).

Do as you please, doesn't worry me. I hope you realise we will be listening to 3.5 hours of Daft Punk followed by 3.5 hours of Pink Floyd.

Sounds good. As long as you are toilet trained. But yeah, I'll book you in if you like? Keen on a Thursday departure? Or I could possibly stay in dunners on Thursday night and then leave Friday morning. Only problem is then we would likely have to leave at some ungodly hour in order to be in Chch to neet up with the rest of them kernts. Cool man. As long as you can handle some danger (pun intended). Just let me know your flight time etc and we will work from there.

Happy to offer a ride to ppls. Could pickup you hamilton goons if you want. It all depends on what time you guys are flying in and when we are meeting up in chch etc. Might be a good idea for everyone to post the time their flight lands?

Keen for Friday meetup, that gives me a deadline of when to be in Chch. And then will be able to give someone(s) rides from airport before rendezvous time.

Cool. Yeah I guess that was an option. I have to have a good look at the factory struts though to see if its even possible. Thing is, I dont really care about the adjustable part of the equation. I just want some replacement shocks that arent hydraulic, but the only stuff I can find for my particular model of vehicle is aftermarket coil-overs. So if I were to mod the shocks with some other "non adjustable" shocks, i'd still need a cert right? (cause they arent OEM replacements) The whole thing just sucks and is too complicated