Connecting sensor via DL1 to Dash 2

westysprinter
Posts: 20
Joined: Tue Dec 16, 2008 12:28 pm
Location: Darlington

Connecting sensor via DL1 to Dash 2

Postby westysprinter » Thu Dec 26, 2013 8:31 pm

Ive connected up an oil temp sensor.
I have and checked the resistance values against the temperature and its very close to the manufacturers data
I've wired it into analogue 1 on the DL1 and used a 1K pull up resistor
running the light monitor on the DL1 im seeing a reading of about 57 on channel 1 - this matches the expected resistance figure at about 10 degrees C
When I set the dash 2 up to read the chanel 1 value with a 1 to 1 value I see -7!
when I input the correct formula for the sensor and pull up Im seeing a value something like 12500!!
Obviously something is wrong - Any ideas
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osborni
Posts: 497
Joined: Fri Dec 07, 2007 9:08 pm
Location: USA, Michigan

Postby osborni » Sun Dec 29, 2013 9:18 pm

What is your forumula for the dash2?
How did you put it in?
Do you have the temperature and resistance curves for the temp sensor?
BMW 2000 M Coupe

westysprinter
Posts: 20
Joined: Tue Dec 16, 2008 12:28 pm
Location: Darlington

Postby westysprinter » Mon Dec 30, 2013 12:31 pm

At work at the moment so dont have the answers around me
Ive used a spreadsheet that calculates the volts to actual readings, its worked for the water temp, fuel gauge, and oil pressure so far.
Ive input these values into the auto calculate section for setting up sensors in dash2 configuration running version 8.5
Im going to drop some tails off the connector block on the back of the DL1 and use my multi meter to see if im seeing the expected voltages across the divider with the 1K pull up resistor, if that works its a Race logic problem, if it doesnt then I have a wiring problem.
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westysprinter
Posts: 20
Joined: Tue Dec 16, 2008 12:28 pm
Location: Darlington

Postby westysprinter » Tue Dec 31, 2013 4:37 pm

well the resistance across the sensor is 53Kohms
the voltage across the back of the DL1 with a 1K pull up is 4.82v
so both indicate approximately 14 degrees - which match the water temp
yet the live monitor on the DL1 says 57.92v and the value on the Dash 2 says 1273
So Ive proved my wiring is correct, looks like a DL1 problem. the Dash 2 isn't getting the correct value hence the bizzare figure. What do I do next?
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westysprinter
Posts: 20
Joined: Tue Dec 16, 2008 12:28 pm
Location: Darlington

Postby westysprinter » Tue Dec 31, 2013 4:51 pm

dropped the analogue signal to channel 2 and getting the same reading 57.9. Channel 1 has gone back to a small background figure
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westysprinter
Posts: 20
Joined: Tue Dec 16, 2008 12:28 pm
Location: Darlington

DL1 recalibration

Postby westysprinter » Sun Jan 05, 2014 11:22 am

another day and we are getting somewhere
I had to download a HyperTerminal emulator! (now I'm a mech engineer!)
There are loads on the interweb, but plenty are loaded with spam etc
there are 2 that seem trustworthy PUtty and the one I used Tera Term
I connected the 5v analogues to the 5v supply and had a 12v supply I connected to the 12v analogues
I ran the procedure to the race tech instructions
however the feedback was that it had failed! I ran it several times, same result.
Felt like a lot of work for nothing. BUT when i reconnected everything the results were correct and I had a reasonable voltage reading!
RACE TECHNOLOGY you need to simplify this procedure!
Polygon motorsport
for all your 7 needs

osborni
Posts: 497
Joined: Fri Dec 07, 2007 9:08 pm
Location: USA, Michigan

Postby osborni » Mon Jan 06, 2014 3:14 pm

Seams like you worked it out.

FYI - the DL1 is a "dumb" logger. It doesn't do any math to translate an input voltage into something "real". The Dash2 and the Analysis program does that. The DL1 just logs voltage values over time.

What I've done with sensors with an unknown output curve is to setup them up on a bench and record the values myself. This is typically with home-brew temperature sensors like you are doing (?).

So basically a pot of water over a stove, thermometer or thermo-couple, a voltage supply and a volt meter.

The input (temperature) / output (voltage) relationship is then put into the Dash2 and Analysis package.
BMW 2000 M Coupe


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