Creating Integrated LCD to display sensory data

[Izzmo]

I think I am going to take up a project which consists of creating a circuit board, attached with LCD screen to display many readily available sensors. As some of you may know, you can read a lot of this data from the OBDII port with your SCT tuner (and a laptop). It will be like that, but instead of hijaking the OBDII port, I will be splicing straight from the PCM module wire loom instead. The benefits allow a faster update of the LCD information. Taking your data from the OBDII port is about 1Hz (or 1 second) too slow.

Here is a short clip on what it will look like from others who have done it. My LCD will be bigger though.

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Anyone know if any body else has tackled something like this (car year doesn't matter)?

 

[Phoenix]

PLX makes that already , and Josh (SHONUT) has that installed in his supercharged sho. Im guessing it can be applied for the V8.

 

[Izzmo]

Who is PLX?

 

[firebat45]

http://www.plxdevices.com/

I'd love to see something like this:
[youtube]Y5i8F4BH424[/youtube]

The SHO cluster is a perfect fit for 2 7" widescreen LCDs.

 

[Izzmo]

Oh yeah, I've seen that. That takes forever to start up though, so yeah. I would like to do something more integrated than have an operating system on there lol.

Plus, he has a huge lag.

 

[firebat45]

I think he has a fairly aggressive smoothing algorithm on the RPM, the turn signals seem much less laggy. 10 second startup isn't forever, it'll be started before you're out of the driveway, and if you start the car, then put on seatbelts, check mirrors, etc, it'll be ready to go when you are. I've got a PC in my car for GPS/Music/tuning, it takes more like 45 seconds to start, and it's not a bother at all.

In any case, running an arduino or something similar instead of a PC would be better for gauges. More crashproof, almost instant on, and smaller/cheaper/less laggy.

 

[Izzmo]

"Check mirrors" --- whaaa.. who does that? lol

Yeah, Arduino is the way to go.

As far as the turn signals, that is almost immediate because he has the signal hooked straight into his computer, versus the signals coming from the PCM have a delay of ~1Hz or more (depending on how he has it setup and it seems like more) because the PCM is doing more than just sending out signals, and it's through the OBDII port.

 

[firebat45]

He's not using the PCM at all, there is no PCM in a car that old (I don't think anyways). At the very least, he states it's not CAN, and he is acquiring the signals directly to the computer. He also states the refresh rate is basically limited by the screen, 70-100Hz, although the tach does look laggier than that.

What kinds of things are you looking to display?

 

[Izzmo]

That's true, I forgot about how old the car was. Well 70-100Hz is very fast, so that's not a problem. It still comes down to the PCM not being able to churn out the updates fast enough, so the clock speed probably isn't very high or something, if it's not limited by his programming that is.

Well, I'm not quite sure yet. I was thinking about prototyping straight off the OBDII connector for now, which limits me quite a bit to essentially just emmissions type sensors.

Later on, though, I think I will tap into the PCM directly.

I will be using the Arduino with a custom shield PCB as the end result though.

 

[SHOZ123]

PCM clock speeds on the Gen 3 are 21 MHz for the '96-'97s, 24MHz for the '98s-'99s.

 

[Izzmo]

Hey Paul, do you have the wiring diagram of the PCM pin out?

 

[SHOZ123]

Yes. What year? Do you want a CD?

 

[Izzmo]

97. I have the CD somewhere.. just too lazy to find it.