johntorg

I have installed and SMT6 and an Using an LC-1 wideband. Both units appear to be working properly with one exception.

When I hook the Analog output of the LC-1 to the SMT6 pin 22, The voltage on the monitoring software reads a constant 1 volt If I put a voltmeter on Pin 22 it shows the correct voltage, and varies with the AFR. If I hook the same LC-1 analog output to a digital voltmeter it reads correctly.

The SMT6 analog output has 3 wires.

1 simulates a narrowband 02 sensor. I have this connected to my old narrowband gauge and it works correctly.

2 is set so that 1 volt = 10 AFR, 1.47 volts = 14.7 AFR, 1.7V = 17 AFR etc. This is the lead I'm trying to monitor in the SMT6

The last is a ground wire, which may be the problem. I haven't connected this to anything, since there doesn't appear to be anything in the instructions telling me where it should go.

If I pull out the analog plug at the LC-1 the voltage displayed on the monitoring software drops to near zero.

I am not sure if its a hardware installation problem (ground wire) or if I have the monitoring software set up incorrectly.

Any and all help will be greatly appreciated.

fast951

John, SMT #22 cannot read a 0-5Vdc signal it reads a 0-1Vdc signal... Hopefully you didn't fry it. (If you did, I doubt the dealer "you" will give you a refund!!)

There is a way to read the Wideband signal, it's a bit more involved to setup. With the VitesseR software it's much easier to do than the standard SMT6... From what I recall you have a unit from the time you were selling the SMT products, you might want to download the latest generic software.

johntorg

John,

Thanks for the information. I doubt anything fried. It makes sense now that I see the maximum 1 volt indication. I can still log on the LC-1, but was trying to get everything in one place on the SMT6. I have an LMA3 on the LC-1 and can now log boost. I also think it may be possible to scale the analog output of the LC1 so that it falls within the 0-1volt range. Eventually I will do a permanent install using an LC-1 and hope to resolve this issue if possible

fast951

Actually, the narrowband input is setup to handle a 0-2Vdc signal. This started years ago , I don't recall the starting firmware version. Not knowing the source or the age of your unit, I can't explain why you are seeing the 1Vdc..
Good luck.

johntorg

John, The units are about 4 years old, but I updated them to the latest software (1.42). I adjusted the analog 2 output to 0 to 1V (.47 = 14.7, 1 = 20 etc.) I'll give it a try tomorrow

Dave951

Did adjusting the output range work? Had a similar problem with my LM-1, that I haven't gotten around to doing anything about yet.

johntorg

No but I think I have a solution. You can input the analog 2 output (1 volt = 10 AFR, 1.47 volts = 14.7 AFR, 1.7V = 17 AFR etc) to any unused 0-5volt input that you are not using for another purpose. In my case it looks as if Engine Temp and fuell AMP are available. Since I only want to log the data, not modify any map with it, this should work.

I think I was suffering from "tunnel vision", in only looking at the O2 sensor input (pin 22) and not the others, Pins 10 and 11.

Dave951

Good call. Same situation for me, I just wanted to log the data. I believe I have the engine temp and fuel AMP available as well.

Keep us updated on if that solution worked (which I think it should).

johntorg

Here's an update: I did input the LM-1 analog 2 (0-5v) output to the Eng. temp input and setup the range as described in this Posting http://www.newtiburon.com/forums/sho...d.php?t=122735 Using his approach, I can now see the exact wideband voltage and the AFR (but only to the nearest whole number) when I playback my log files. I would really like to extract the wideband voltage from the log and graph it. There appears to be a remaining problem:

When I look at the log records, some of the fields are apparent, inlcuding the Wideband AFR to the nearest whole number (12, 13 14 etc.). Unforunately, I cannot find the Wideband voltage. It is in the log record somewhere, because it displays during playback. I have tried converting all of the numbers in the .raw log record manually (log value/255*5?) and can't find anything that looks like the wideband voltage.

If anyone has experienced this problem, Input would be greatly appreciated.

johntorg

Here are charts of the APR from the LM-1 and the SMT6 for the same timeframe. As you can see they do correspond. There is a slight voltage and hence AFR difference, probably due to a ground offset between the LM-1 and the SMT6 and/or slight timing differences between the two (The LM-1 logs about twice as fast as the SMT6).

See below for more details.

johntorg

I finally figured it out. The 0-5 voltage of the LM-1 is located in column R of the Excel spradsheet after you open the .raw log file, using commas and spaces as the separators. The formula to convert the data to AFR is =R???/255*5*3.008+7.35, with R??? being the cell containing the raw data. Basically you are first converting it from the SMT6 .raw log format to a viewable voltage and then converting that voltage to AFR, using the slope of the 0-5V analog output (3.008) using the formula y=MX+B. Thanks to Dmdicks and Nickfd on the Tiburon forum for getting me started in the right direction. (See link above)

johntorg

If anyone is interested, I can put together a separate DIY for this.

Yes I know its running way too rich

Dave951

Good to see you got it figure out. I'd be interested in a DIY for it as well.