Thread: MegaSquirt ECU and CarPC

Bump. Anybody have input on how to do this?

Why don't you check TunerStudio?

Okay, so after playing around with TunerStudio for awhile I have noticed it has no speed read out, is there a way to add a speedometer function to the dashboard in TunerStudio?

Well I am not sure that you can't show speed in Tuner Studio, however I am not very familiar with it so I can't be sure about it..

You can write your own software for MS and read speed howvere this requires programming skills..

After playing around with TunerStudio I have decided that I would like to use it as a primary dashboard run from a carPC, and for retuning purposes. Should I be considering running This system from a separate computer than I will run my GPS / Media stuff from?

I'm looking into running megasquirt for my 240sx when I go turbo and therefore have been looking into the same idea. My roommate happens to be an awesome programmer so we have already had a few conversations over beers and for the most part, programming a digital read out of the information should be fairly simple. I'm semi decent with the graphical side of things so I plan create the gui. The only concern I have is the idea of a desktop type computer being my only way to view gauge information, especially if it's trying to play 1080p or running a visualization from a media player.

I'll probably build a dedicated system that will handle the one and only task of reading information from megasquirt and displaying it. Once I get more development on the idea i'll post our latest theories.

On the fly programming was something I used to be really interested in until after reading the KA-t.org forums I found that once you get a great running tune, you really don't need to re-tune on the fly. The megasquirt can use the TPS to see how far your foot is into the gas and go from there, when you create your map, you can play with how much the tune will change based on how much gas you are giving it. Most of the veteran users suggest finding a good solid tune, and then adjusting the additional values once the car runs good and can be driven down the road smoothly. All of that tuning would be much better off with a friend driving and you sitting in the passenger seat with a laptop giving you direct control. Once you have it pretty much dialed in, there really shouldn't be need for additional tuning, unless something changes.

But then again, that is just my reading experience from the 240 forums.

I had the same concerns about the reliability issues with this setup, so my plan now includes a fuel gauge, speedo, and tach mounted on the dash, and I may decide to make them retract into the dash. My intentions with the on th fly tuning would be basically just to load up different tune, like a sport mode and a comfort mode. If you are just going to run a dedicated gauge only system that could probably be done with an Arduino, but I wanted the ability to display the gauges on what ever monitor I choose, and to be able to use the drivers screen with the computer. The thought of running a VM also came to mind, to help isolate the media end of things I would run the MS programs on Linux and run a front end on a Windows VM, but to do that would require a more powerful computer. Take a look at the pre-build thread in my sig, it addresses this subject as well.

Originally Posted by Veritas

On the fly programming was something I used to be really interested in...

Why not use self tuning? (Especially if you have an awesome programmer - that assumes you can read the sensors (eg, injector squirt, O2 sensor etc, acceleration) and mod the running map.)

Originally Posted by BoyRacer0013

I had the same concerns about the reliability issues with this setup, so my plan now includes a fuel gauge, speedo, and tach mounted on the dash, and I may decide to make them retract into the dash.

That's an interesting idea. I figured I would just leave the stock harness in the car for the OEM gauge unit and if something happened I could just swap it in and be back to stock in a heartbeat.

Originally Posted by BoyRacer0013

My intentions with the on th fly tuning would be basically just to load up different tune, like a sport mode and a comfort mode.

I was thinking the same thing, until i came across the following information on their site.

MegaManual :: Switching fuel maps for a single type of fuel is an out-dated "carburetorism" that you don't need with a properly tuned EFI setup (the low load part of the tune is set for economy and the high load is tuned for power; trivial with EFI, hard with carbs). The 'switch' is the throttle pedal. MegaSquirt® can detect when you want more power (with the TPS and MAP sensors) and make the 'switch' on its own. If you've got the throttle almost closed and are cruising down the freeway, a well tuned MegaSquirt® will lean things out for maximum fuel economy. Then when you floor it, the sensor readings change and MegaSquirt® will go into the full power section of its tuning.

Originally Posted by BoyRacer0013

If you are just going to run a dedicated gauge only system that could probably be done with an Arduino, but I wanted the ability to display the gauges on what ever monitor I choose, and to be able to use the drivers screen with the computer. The thought of running a VM also came to mind, to help isolate the media end of things I would run the MS programs on Linux and run a front end on a Windows VM, but to do that would require a more powerful computer. Take a look at the pre-build thread in my sig, it addresses this subject as well.

I was thinking about an Arduino setup, but the Arduino is really limited in the ability to output information onto a digital screen directly. I've seen lcd controllers up to three inch but I'm looking into running a 7" setup in my guage cluster area, similar to this setup . My only challenge is that I don't have OBD-II so I will have to get all my information from megasquirt.

My friend and I are looking to see if they have an API for megasquirt. Once we figure out what language to use, it will be fairly simple to set it up. I plan to use a dedicated system, running a version of linux without running the gui. Should lead to quick load times and also won't have the overhead of running anything other than the gauge program itself.

I'm real hesitant to trust a vm as it still relies on the host system staying up. I'm not sure how the vm would feel about constantly being shutdown due to the host powering down or getting put into standby as the host system goes into standby. And a system that would need to be the host is going to draw quite a bit of power. The advantage of a VM though is quick rebuild and reboot times.

Originally Posted by OldSpark

Why not use self tuning? (Especially if you have an awesome programmer - that assumes you can read the sensors (eg, injector squirt, O2 sensor etc, acceleration) and mod the running map.)

I've considered that as an option but in their manual they advise that it takes a lot of "By the seat of your pants" tuning to get things right. Parameters and math are great tools, and will allow you to dial things in pretty closely if you understand all the variables your looking at and know how much each adjustment will effect everything but to program an auto tune would, IMO, lead to a very weak tune that simply keeps the car running, similar to what a stock tune on a stock ecu does. I've read many threads of members tuning and then re tuning, and then continuously re tuning, just to dial things in perfectly.