Laptop for guages question

[Techno]

I've been thinking again.

I know a few have thought of this so I was wondering how hard would it be to use an old laptop for gauge readouts- all of them, maybe more than needed.
The pressure and temps can be bought binary so that part is easy. And I understand some of them can be "polled" so only one wire would be needed if that was a problem.

The EGTs are analog, can the computer do this internally? Or is an A/D converter needed.

The Tach is freq/voltage so again can the puter take the freq and read it as an RPM?

How fast a puter would be needed to read these gauges?
How difficult would it to be to write the program for the on screen gauges? I have visual basic and it seems that it should be easy.
Analog and digital?
What about data logging? Would it be hard to do?
How about the NMMA or whatever from a GPS?
Thinking a small color display would be nice but even monochrome would work fine. Can these be seen in sunlight?

Are here enough ports on the puter to take all this stuff?

[B.Leonard]

Yeah right :rolleyes: Forget it.

You can't use that PC for real time applications directly like you are implying UNLESS there is a controller in between the PC and the sensor, essentially taking the PC out of the real time loop and making it just display logged data.

If you're gonna do processing on those analog signals it would be best to convert to digital and then process via gate array, asic or DSP. Either way you would still need some type of controller for each sensor to at least bring voltages down and maybe convert to digital if needed.

Many systems use a PC to configure and show data from a "run", however there is a dedicated processor like a DSP that actually samples/polls for that data from the sensors in a real time fashion. Just logging is not really time critical but processing would be, i.e changing a fuel curve based on EGT values while turning 8,000rpm. That's when you would need a very fast processor dedicated to handling large amounts of digital "samples" from an A/D converter, analyzing, then performing some logic based on the data to alter the performance of the engine.


-BL

[Adam McKeon]

I have an idea! Take your water pressure sending tube and put in you usb port hehehehehehehehehehehe!!!!! That will fix it!:D :D :D :D :D :D :D :D :D

[Cp]

Actually, alot of the current laptops, (all from at least one major manufacturer), have Controllers in them in addition to the pentium or whatever processor. The EC's (embedded controllers) have all the capability necesary to do anything you'd want. They have lots of I/O pins, Logic level stuff, Analog inputs, Dig and Analog Outputs, clocks, etc. Now just get someone to give you the source code for the EC and you're in business. Good luck there. Most companies consider firmware of these types to be proprietary. Nevertheless it sounds like a fun project.

[speedyfast]

nm

[D rocket]

Motec will do everything your wanting to do including amazing data logging print graffs and comparisons and overlays. you can do all of this from a dash only unit(without the engine management system). Check out your EGTs verses RPM . With the new 20htz Gps you can also overlay all data 57 times a second. This gives you foot per second ,time to distance ,Et and speed. flick a switch and KNOW et and speed . It's very accurate and repeatable. Everything downloads to your laptop.

DeWitt

[98Mirage]

I seem to remember a new member looking for input from us performance boaters to create a new device/product, but, I can't remember his name? He sounded very intelligent in the digital world. I think a concept like yours would be a piece-of-cake for him!

Automotive uses data acquisition with real time or history playback.

Your idea could be a new "Racepak Type" guage.

Dennis

[B.Leonard]

There you go Techno!

If you can get a PC that has some type of "universal" controller in it as CP said, you should be on your way. You won't need to know anything about the inside of the controller except the interface to it from the operating system side (driver) and the inputs from your sensors (tach, temp etc.).

If the PC has the card in the box I'm sure the interface is published somewhere. Then you will need a driver library or dll for whatever language you choose to use (i.e basic, C etc.) but then again if the PC has the controller card it should be available somewhere.

With that system I'm sure you could easily program a "real enough" time gauge to monitor engine temp or rpm. Depending on what is running on the PC (since the PC operating system is NOT real time) it should monitor fairly smoothly. However it is not robust enough as an engine control system, once you brought up solitaire your fuel injectors would stop firing for a second or two and the engine could either burn up or shutdown LOL! :rolleyes: ;) Linux would be a better OS but you might not be able to find drivers for that controller unless Linux was the std OS. I think IBM offers Linux stock on there PCs, check into one of those.

-BL

[BarryStrawn]

Techno - Capturing NMEA data is trivial. Just use Windows Hyperterminal to serial connect and capture as a text file. Same cable as you would use to flash program the GPS or link with any of the laptop mapping programs. You could post process the file with something like Excel or just look in the text file for the data. Speed with be in knots in the $RMC sentence. Field after the eighth comma if I remember correctly. Records come in at 1Hz. If you want to output the GPS data as an onscreen readout then you will have to do some programing. Visual Basic is a good choice.

The rest depends on what you want to do and how cheap you need to get. All DOS and Windows PC's since the dawn of time have had support for a multi-channel analog to digital converter. It's called a joystick. Resolution isn't laboratory grade but the newer ones USB attach and have 6 analog channels and a bunch of digital on/off inputs per joystick. If that isn't enough, you could have several attached. Gut one for the USB interface and reuse the potentiometers to measure the motion or position of things like steering, trim, jackplate, throttle or whatever. Some signal conditioning circuitry would be needed to hook up temperature or pressure sensors. Calibration may also be a challenge no matter how you do this.

Most parallel ports can be used as a digital input. Should be fast enough to hack a frequency counter for the tachometer. But you would have to buy a software toolkit or write a fair bit of assembler code.

The easiest way to do this on a laptop is to just buy a data acquisition package with a PCMCIA interface card and instrumentation software. Probably $300-$400 to get started.

Something like the Motec would be nice if you can afford it. Racepak also has full data systems including data acquisition, digital dashes, and even analog gauges driven by the digital information.


Barry

[Techno]

speedyfast mentioned it not being a sun worthy display. That is the whole heart of it. The screen would be chopped up in large digital readouts and would also do analog for those better outputted to analog view. If you can't see it though then getting the rest to work seems a waste of time.

EGTs are slow responders so they don't matter. The only fast one I can think of is RPMs and maybe fuel pressure.
All the pressure and temperature senders can be digital output. The signal to the puter is digital. No calibration since its done on the chip.

Some of the other stuff mentioned has me lost.
Any displays veiwable in sunlight? There must be something out there. Wasn't there a different type of display before the lcd panels?