Car computer question

[frankendat]

Google is no help, or too much help, to find an answer. Nissan ECU's, Megasquirt, Microsquirt, etc. are computers that interface with the engine via sensors. It would seem the aforementioned devices interpret sensor data and provide an interface for user access, but these devices use, or have the option to use, a PC/laptop.

 

My question: Is there software or at least a slimmed down (cheap) physical interface with software that would allow a laptop to be the ECU? A permanent mounted (cop style) laptop that functions as the full time ECU.

 

A decade old laptop has multiples more computing strength than a Nissan ECU, especially a 20 or 30 old vehicle ECU. There are temperature, vibration and other considerations important to vehicle ECUs designers, that have been answered (see cop laptop), so the focus should  remain on how/if a laptop could be "wired" in without a middle (ECU) man. There are adapters that allow a laptop to plug into an OBD1 port on the vehicle, for diagnostics. If there is need to plug the sensor receptors directly into the laptop, a radio shock DIY motherboard arrangement could accommodate the output wires from the sensors

 

ECU's like Megasquirt are expensive and have remained expensive, even as electronics have become cheaper and/or are "knocked off". I do not like middlemen.

 

 

[thisismatt]

Haven't seen one.  You would still need an interfacing peripheral as the laptop does not have the I/O capability to "talk" directly to the sensors or control the other engine management devices (injectors, solenoids, ignition, etc).  Then I imagine it would still be iffy considering the high level OS the laptop is running..in other words, the engine needs constant, dedicated input & output response without interruption or hang-ups.  Don't need your engine stalling out because windows update decides it's time to update your antimalware 😉  Plus, waiting for the OS to boot...

[Satisaii]

I have quite a bit of experience with aftermarket ECU stuff.  To put it simply, an ECU has 2 parts: a small computer and the interface that allows it to control the engine.  Most of what you pay for is in the interface.  Getting that to work right as a DIY project requires some EE knowledge and lots of time with an oscilloscope. Been there, done that with the early MS stuff.  Tuning trimmable pots to exactly match the output of a Hall type sensor, which is temperature sensitive, was not the highlight of my race car building career.   I cried tears of joy when MS got rid of those pots.  Many hours wasted there, and now I just pay for a device that works.

 

But if you have time on your hands, and your time is not worth that much, you may be able to recreate the interface and then devise a scheme where it runs via USB.  So you are going to replace a small computer (basically a few capacitors/resistors on a board with a controller chip that is designed to do nothing but run a car) with your laptop that is... well, a jack of all trades, but not a master at running a car.  I love my laptop but it still gets a BSOD every now and then.  I don't want that to happen in the middle of the zombie apocalypse in my get away vehicle.

 

If you are still really motivated to learn more about controller electronics, go lurk about a DIY EV forum.  Might not directly apply but it is interesting stuff.

 

Or maybe an Arduino EFI might do what you are looking for.

[Str8jacket]

A computer runs via a different execution order to a micro processor used in an arduino or a PLC style controller like an EFI control. I am shit at remembering specifics but I do know a PLC has a set run sequence from start to finish the same every loop. A computer can execute different functions when required but it is not necessarily in the correct order to run a machine. To run a machine you need to have the exact sequence of events happen in the order in which it has been programmed to ensure certain parameters are met before the next condition is started, ie don't fire spark plug until engine crank position is met. 

 

I have programmed a few PLCs and then had to learn to program a HMI display that runs via a more computer like run time. It is fucking frustrating to have random shit work one minute and not the next because the execution order is out. 

[datzenmike]

 

[Wildcat Walker]

You need to specify what engine you wish to control, and what sensors you intend to use as inputs/outputs. You can take an engineering course on control systems once you get past all the math and physics. 

[Stoffregen Motorsports]

10 hours ago, thisismatt said:

Haven't seen one.  You would still need an interfacing peripheral as the laptop does not have the I/O capability to "talk" directly to the sensors or control the other engine management devices (injectors, solenoids, ignition, etc).  Then I imagine it would still be iffy considering the high level OS the laptop is running..in other words, the engine needs constant, dedicated input & output response without interruption or hang-ups.  Don't need your engine stalling out because windows update decides it's time to update your antimalware 😉  Plus, waiting for the OS to boot...

My tuner laptop has never connected to the internet. So no updates, but I get what you're saying.

[frankendat]

4 hours ago, Stoffregen Motorsports said:

My tuner laptop has never connected to the internet. So no updates, but I get what you're saying.

We are of same mind. I have a few military surplus Toughbooks that I use for specific functions (like a Tuner). Each has the programs necessary, a streamlined  Windows 7, and not much else. I removed all modem/wireless pieces in one, the others have modems/wifi, but it must be physically activated before or during startup to function. They make a slick Toughbook/Getac docking station, that you see in police cars, I keep looking for a surplus cheap one. It is what prompted this question. With a lockable docking  station, I wouldn't have a problem mounting a permanent Toughbook. Instead of using it only as a occasional tuner, have it continually, automatically adjusting for optimal operation.

But, the consensus provided by those more knowledgeable, for a number of reasons, those I understand and those I don't, this dog won't hunt. Damnit

[frankendat]

13 hours ago, Satisaii said:

I have quite a bit of experience with aftermarket ECU stuff.  To put it simply, an ECU has 2 parts: a small computer and the interface that allows it to control the engine.  Most of what you pay for is in the interface.  Getting that to work right as a DIY project requires some EE knowledge and lots of time with an oscilloscope. Been there, done that with the early MS stuff.  Tuning trimmable pots to exactly match the output of a Hall type sensor, which is temperature sensitive, was not the highlight of my race car building career.   I cried tears of joy when MS got rid of those pots.  Many hours wasted there, and now I just pay for a device that works.

 

But if you have time on your hands, and your time is not worth that much, you may be able to recreate the interface and then devise a scheme where it runs via USB.  So you are going to replace a small computer (basically a few capacitors/resistors on a board with a controller chip that is designed to do nothing but run a car) with your laptop that is... well, a jack of all trades, but not a master at running a car.  I love my laptop but it still gets a BSOD every now and then.  I don't want that to happen in the middle of the zombie apocalypse in my get away vehicle.

 

If you are still really motivated to learn more about controller electronics, go lurk about a DIY EV forum.  Might not directly apply but it is interesting stuff.

 

Or maybe an Arduino EFI might do what you are looking for.

BSOD?

It is funny you mention the DIY EV cats. I have lurked, even posted on some DIY EV boards and found valuable information, only slightly related to EV's. I am not even fan of EV's. In the States they should be labeled "coal powered vehicles."

I ran across a couple of guys who offered an Arduino EFI setup a while back. It was much cheaper than MS but it couldn't do sequential (individual cylinder) tuning. I am a simple untrained hack, when it comes to computer controlled cars and prefer mechanical, but computer controlled cars have been around long enough and perform well enough to no longer be ignored. Learning new tricks is a long and tedious ordeal. Thanks for weighing in.

[bottomwatcher]

You are getting way ahead of yourself and nissan obd1 didn't have a plug in port. Just a flashing code of pulsating LEDS. Obd2 got the port and universal code readers. The computers did become a lot more complicated learning your driving habits and compensating for such things as clutch pack wear in auto transmissions. Still the early ones could be reset by just disconnecting the battery. Anyways what are your specific goals here?

[thisismatt]

28 minutes ago, bottomwatcher said:

You are getting way ahead of yourself and nissan obd1 didn't have a plug in port. Just a flashing code of pulsating LEDS. Obd2 got the port and universal code readers. The computers did become a lot more complicated learning your driving habits and compensating for such things as clutch pack wear in auto transmissions. Still the early ones could be reset by just disconnecting the battery. Anyways what are your specific goals here?

I'm pretty sure it's to overcomplicate and spend more money than he would on a standalone to avoid paying the man 😅

[frankendat]

19 hours ago, thisismatt said:

I'm pretty sure it's to overcomplicate and spend more money than he would on a standalone to avoid paying the man 😅

 

20 hours ago, bottomwatcher said:

You are getting way ahead of yourself and nissan obd1 didn't have a plug in port. Just a flashing code of pulsating LEDS. Obd2 got the port and universal code readers. The computers did become a lot more complicated learning your driving habits and compensating for such things as clutch pack wear in auto transmissions. Still the early ones could be reset by just disconnecting the battery. Anyways what are your specific goals here?

I'll have you know and it can be confirmed by my wife (she keeps score)that my custom work arounds perform, as good as or better, for less out of pocket MORE than 50% of the time. The downsides are the work arounds take a minimum of triple the time and if they fail, I've spent time and money and the problem remains.

I'm trying to take more time on my first foray into computer controlled cars, as money is tight, because while I would like to deny it, my SOP for learning new tricks is trial and error. (I did pick up a box of Z22 ECU's a KA24E ECU and an "Enthalpy" (I am not spelling that right) chip/mirco board to run a turbo. Both are contingency plans)

 

My goals are not outlandish. If, at the end of it all, my rig performed like bottomwatchers, then I would claim success. What complicates is in the time between bottomwatcher and my build, prices have gone silly for new parts and for old parts, now claimed "vintage". I am not a purist and look to incorporate parts from cars and trucks, newer and "better" (at least more readily available) then the 85 Nissan, but that remain in the window of old and common (cheaper) not in the window of vintage and cool (over priced). So far I have found some luck with hardbodies.

 

This latest likely waste of time is simple. I purchased a Toughbook to be a dedicated tuner laptop, for the purpose of maximizing performance, primarily through ignition, fuel and air adjustments. There are many ways to skin this cat, most of them (especially ardunio solutions) have a steep learning curve. I am already a half assed computer user

 

(which is a bummer, because I know enough to realize how bad we are getting conned but not enough to confidently work around all of it. Like most, I guess, I do little things in hope to make me a little more pain in the ass to harm then the next guy)

 

since a laptop is often used to monitor and adjust ignition,fuel and air parameters--Bobs your uncle. Sadly, it is sounding that such is not the case.

[thisismatt]

Yes and no. The laptop computer only monitors and programs the standalone, it doesn't actively control anything in real time. It's kind of like compiling a program from source code, or rendering something CG.  Once rendered you can playback in real time, but the complex rendering isn't done in real time.

[bottomwatcher]

I am relatively incompetent on the computer other than the basics. Going to fuel injection over carb is big step. Doing it with factory stock components even I can do. If you can follow a wiring diagram and you have the components sitting in front of you it's just plug and play. Reliability of ecms? Well I have 3 over 30 plus years old and all 3 work fine. You can get them professionally refurbished so I am not worried about ecm obsolescence. Also you are correct I have a hardbody drivetrain so if something poops the bed I just go to the hardbody section of used parts and it is 10 parts to 1 vs 720. I am even rocking some frontier components so 10 times more availability as hardbody. I have had my truck since I was 17 so I have no issue doing what needs to be done to make sure it is a reliable meat wagon to take me on my last ride 

[slowlearner]

I've read most of this. Forgive me if I miss some details. 

 

I think the main issue againsta laptop for an ECU is being, "fit for purpose". Kinda similar discussion here...

 

https://forums.raspberrypi.com/viewtopic.php?t=97514

 

I mean, you could but it won't be a "laptop" anymore. 

 

So, for 7 times the hours making it work without any customer support, I'd rather stick with a megsquirt (or whatever you want) And I'm a real tightwad. You get what you pay for. 

[frankendat]

16 hours ago, bottomwatcher said:

I am relatively incompetent on the computer other than the basics. Going to fuel injection over carb is big step. Doing it with factory stock components even I can do. If you can follow a wiring diagram and you have the components sitting in front of you it's just plug and play. Reliability of ecms? Well I have 3 over 30 plus years old and all 3 work fine. You can get them professionally refurbished so I am not worried about ecm obsolescence. Also you are correct I have a hardbody drivetrain so if something poops the bed I just go to the hardbody section of used parts and it is 10 parts to 1 vs 720. I am even rocking some frontier components so 10 times more availability as hardbody. I have had my truck since I was 17 so I have no issue doing what needs to be done to make sure it is a reliable meat wagon to take me on my last ride 

We are of like mind. I started with the Z22 components, as I was correctly informed (Thank you Ratsun) that the Z22 setup was basic and understandable. It is, but the more I read, the more it seemed that it would not fulfill my goals. Like any American, I want more for less, but again, if I can match your performance, I will declare success. But, I am hopeful that the extra steps I have taken, will yield at least a single digit percentage better.

 

 

 

 

[frankendat]

18 hours ago, thisismatt said:

Yes and no. The laptop computer only monitors and programs the standalone, it doesn't actively control anything in real time. It's kind of like compiling a program from source code, or rendering something CG.  Once rendered you can playback in real time, but the complex rendering isn't done in real time.

So, when I see JDM kids at stoplights tapping their laptops and racing about downtown, they are modifying parameters based on information gleaned from their last "race"; they are not modifying parameters in real time-Yes?

But the JDM kid is modifying parameters with the laptop or more precisely JDM kid is modifying a program on the laptop that converts the information into language readable by the car computer, he then adds the information (flashes?) the information onto or into the car computer, which changes it. The "change" happens in real time, but the change is not based on real time information-Yes? . My racing days are long past, the example is to clarify understanding.

 

Once parameters are adjusted on a Z22, Z24 factory computer or aftermarket, how efficiently do they automatically adjust for temp/elevation/hwy or city etc? Elevation on a few hour trip can be +/- 2500ft, couple more hours +/-5000ft on the highway, +/- 8000ft if venturing off road,and temperature swings from over 100F to -20. 

 

When I started this journey a few years back, I didn't know what I didn't know and have back pedaled a few times, that, the economy and old Nissan's new popularity, make this a marathon build.

[frankendat]

On 3/23/2023 at 8:55 PM, bottomwatcher said:

You are getting way ahead of yourself and nissan obd1 didn't have a plug in port. Just a flashing code of pulsating LEDS. Obd2 got the port and universal code readers. The computers did become a lot more complicated learning your driving habits and compensating for such things as clutch pack wear in auto transmissions. Still the early ones could be reset by just disconnecting the battery. Anyways what are your specific goals here?

Goals 30+ mpg city and hwy (city =everyday smooth and speed limit or a little below driving, neither consciously hypermiling nor constantly switching lanes and accelerating/decelerating in attempt to achieve some magical "pole position" /hwy best would be 70+ with cruise set, but if it brought the desired mpg, I could settle for manually maintaining an optimal rpm, but not if it put me under 60.

[frankendat]

18 hours ago, slowlearner said:

I've read most of this. Forgive me if I miss some details. 

 

I think the main issue againsta laptop for an ECU is being, "fit for purpose". Kinda similar discussion here...

 

https://forums.raspberrypi.com/viewtopic.php?t=97514

 

I mean, you could but it won't be a "laptop" anymore. 

 

So, for 7 times the hours making it work without any customer support, I'd rather stick with a megsquirt (or whatever you want) And I'm a real tightwad. You get what you pay for. 

Now that is a hell of a thread. It brought as many questions as answers and a good bit was over my head, but excellent resource.

[Stoffregen Motorsports]

I just spoke to a guy over the weekend who used an arduino to control his 8 speed auto trans.

[Str8jacket]

6 hours ago, Stoffregen Motorsports said:

I just spoke to a guy over the weekend who used an arduino to control his 8 speed auto trans.

I was going to suggest either Arduino or a Texas Instruments MSP430 would be the best start. Arduino is programmed using Python like language and the MSP uses C. 

My boy is learning arduino of YouTube. There is a old dude on there with tons of tutorials.  Really good. 

If you download an APP called Udemy and buy a starter board MSP430 you can learn how to program it for free using the Udemy platform. I started to learn C this way. 

Any dedicated PLC with enough inputs outputs to run EFI is going to outcost a stand alone easily. 

[frankendat]

7 hours ago, Stoffregen Motorsports said:

I just spoke to a guy over the weekend who used an arduino to control his 8 speed auto trans.

That is cool, I guess. Hopefully you gave him a little bit of a hard time. First, "they" stop producing manual transmissions, now "they" give up control of their auto trans. Next it will wash your ass and if the power fails or there is a glitch the world is swimming in shit. :)

[frankendat]

1 hour ago, Str8jacket said:

I was going to suggest either Arduino or a Texas Instruments MSP430 would be the best start. Arduino is programmed using Python like language and the MSP uses C. 

My boy is learning arduino of YouTube. There is a old dude on there with tons of tutorials.  Really good. 

If you download an APP called Udemy and buy a starter board MSP430 you can learn how to program it for free using the Udemy platform. I started to learn C this way. 

Any dedicated PLC with enough inputs outputs to run EFI is going to outcost a stand alone easily. 

Not only was my idea impractical it would be more expensive? Sheesh, I stepped in it this time

[Str8jacket]

Not having a crack at ya, just what I have learned from personal experience. My attempt at entrepreneurship involves building electronically controlled hydraulics systems.

Full manual / analogue systems are good but any more than 2 step functions to control maybe ok for yourself but it only takes a mistep and you can seriously fuck something. Take the auto Stoffregen was talking about, how do you correctly control this with a switch or lever arrangement? The tuning requires precise engagement of the next clutch packs at the exact time to overlap the previous one disengaged, there are fill times for apply and release, different series of clutches need to be used depending on direction and gear. What happens if you accidentally hit the reverse switch while doing 100 in forward? 

The wiring to get it to work would then require a swag of 16pin relays with interlocking setups to get to work, it is a fucking nightmare to troubleshoot.

A PLC based microcontroller that cost 16 dollars and a breakout board can do all that easily.  Then spend double the time it took to program it to work to program it to self diagnose faults and troubleshooting. 

I reckon it's worth a shot at doing g if you have the time and willingness to learn, just don't hamstring yourself from the start with the wrong base layer

 

[frankendat]

I didn't think you were having a crack at me, quite the contrary, you provide information to prevent me from cracking myself. But, what is more interesting....

 

28 minutes ago, Str8jacket said:

My attempt at entrepreneurship involves building electronically controlled hydraulics systems.

I have much interest in this field and was investing heavily in the early 2000's. I believe/believed hydraulics in active suspension and regenerative propulsion would be the next big movement in vehicle hybridization. Electricity, being primarily produced by fossil fuel in the United States and the environmental problems with battery production/disposal would deter the electric car "fad". It didn't work out. When given a chance to invest in Bitcoin early, I laughed it off. "You want people to pay tangible currency for imaginary currency, that you admit holds no intrinsic value? Nobody is going to do that..." My friends keep pushing me to sell everything and invest with national and international defense contracting corporations, it's our best shot at world peace.

I'll send you a PM