RPM display not working on DASH1

[vtluu]

Related to the other DASH1 RPM thread but my setup is a bit different.

I've a DL1 installed in my Mitsubishi Lancer Evo 8 that I've used with great success for about 1.5 years. I recently bought DASH1 unit. I've upgraded the firmware on the DL1 to the version 7 firmware I found. I've verified the DL1 works and communicates correctly with the DASH1--lap and sector time display works, etc. I have a DASH.DAT file configured for the DASH1, setting the RPM counter to 2 pulses per revolution (the same value I use in the RT software).

However the RPM display doesn't appear to work. The DL1 correctly logs the RPM (and I played it back in the RT software to make sure the RPM signal is glitch-free). The DASH1 indicates some slightly varying value that doesn't really correlate with the engine RPM--e.g. I rev the engine up and the value doesn't change. Occasionally I'll see a "flicker" of the correct RPM value on the DASH1 but it immediately returns to the incorrect value.

I haven't yet looked at the DL1 Monitor to see if the RPM is correctly displayed there.

I tap the RPM at a wiring harness leading to the tachometer and run it into the "RPM (5V)" input in the DL1. I don't have any grounding other than the chassis ground; should I hook up the "Ignition Ground" wire to something?

The signal may be slightly different from that which goes straight to the ECU but has worked correctly with the DL1 and a couple of shift-light and gear-display devices that I've used. I looked at the RPM signal on an oscilloscope a while back: baseline zero volts, each pulse is a square pulse hitting around 9.4V with a length of 10 milliseconds. 2 pulses per revolution.

Any ideas as to what might be wrong? Thanks for any help...

[jasonc]

What dash config software version are you using? The latest software uses a different dash setup which requires the rpm scaling to match the scaling factor in the dl1 analysis software. Previously there was some sort of adjustment required.

[vtluu]

I'm using the latest V6 software (analysis and DASH/DL1 config) posted to the website (as of two days ago).

After a bit more trial-and-error I got the RPM display to work correctly. I'd overlooked the fact that RPM can be configured with an equation; previously I'd only used the "RPM" tab in the DASH1 software to set up the RPM display.

Oddly enough the right equation turned out to be "y = 3x" which is what the "RPM" tab sets up if I specify 2 pulses per revolution. So it's not clear why setting things up through the variables tab fixed things. The one other thing I did change was to enable "GSM Modem" mode in the DL1 setup since I'd read it was needed for the start/stop button function to work on the DASH1.

Anyway, thanks for your help Jason!

Now, on to the next problem:

The shift lights don't quite work. For testing I set it up to 3800 RPM maximum, 200 RPM per shift light. When I rev up the engine, the shift lights do work--intermittently. It's as if one part of the firmware is turning them on and another part is deactivating them. For example if I hold 3800+ RPM long enough I'll briefly see all the shift lights illuminate. They don't come on right away and they only stay on for a fraction of a second before turning off again. It's not that big a deal since I hadn't planned on using the shift lights on the DASH1 anyway (it's mounted too far out of my line of sight), but I thought I'd mention it.

[ewaher]

Tam, I'm having a similar issue with the DASH2. I think it has something to do with the filtering on the dash settings. I believe my filter is averaging too many samples together causing the reading to respond slowly.

Anyway, come to Streets of Willows with Speedventures in the next two months and we can figure it out.

Erik

[vtluu]

Hey Erik, fancy meeting you here.

'Fraid I won't be seeing you down south this year. I'm closing out this season with a day at Infineon Raceway next Sunday, then three days at Thunderhill the following weekend (instructing on Friday, racing with ARC Sat/Sun).

Anyway I haven't made any headway on the shift lights problem. Instead, I've been fabricating a mounting bracket for the DASH1. In the meantime I've set the shift lights to 10000 RPM so they won't be bothering me.

[ewaher]

I fabbed up a bracket for the dash...velcro. Booya

[vtluu]

Velcro would work for a flat surface but my DASH1 is fitted over where the HVAC knobs used to go. I made a bonded-aluminum bracket to mount it:



FYI once I enabled the "GSM modem mode" on the DL1, the start/stop and lap marker buttons on the DASH1 started working.

[moc]

Hi Guys,

Check the RPM Update Frequency for the serial port in the DL1 configuration program. This should be set to at least 25Hz to keep the dash up to date with the quickly changing RPM.

[vtluu]

Thanks, I'll do that... at some point. My "RPM source" is indefinitely out of commission, as I wrecked the Evo last weekend at Infineon Raceway.