Engine monitoring system

syfuga

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Joined
21 Mar 2005
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310
Location
Back in UK waters
www.syfuga.co.uk
I am looking for help with someone who knows engine monitoring and instrumentation.

We have an old VDO Logic Combi that monitors and controls our Yanmar engine. Unfortunately the LCD has gone, and cannot be replaced.

The Logic Combi controls start, stop, alarm, displays fuel level, oil pressure, coolant temperature, battery voltage, engine hours, and includes a tachometer.

I am planning to attempt to build a replacement monitoring system using an Arduino Uno, a microprocessor system that has built in analogue inputs, and digital input and output capability, probably in association with a Raspberry Pi micro computer for additional display purposes.

Unfortunately our boat is in Southern Brittany, and so experimentation and taking measurements is awkward, and we cannot operate without something in its place, so I'd like to go prepared.

I need to know the range of resistance used by the Yanmar oil and temperature transducers, and how they are normally wired. I imagine that with electrical guages a 12v supply is used, and there is some means of calibration. The motor ground is used to return the signal (0v.).

I presume, but could do with confirmation, that the alternator output is used to pulse the tachometer, probably via a capacitor within the Logic Combi.

I have already bypassed the Combi's start function with a key switch. I propose to introduce a new 'stop' button to operate the solenoid.

There is no room on the steering console for fuel level, oil pressure and temperature guages, nor an obvious and practical alternative elsewhere in the cockpit.

If I can make it fly, it would be a nice little product. The Uno is only £16 from Radiospares.
 
I need to know the range of resistance used by the Yanmar oil and temperature transducers, and how they are normally wired. I imagine that with electrical guages a 12v supply is used, and there is some means of calibration. The motor ground is used to return the signal (0v.).

Try looking up the specs for VDO oil and temp displays, they should tell you the ranges for the senders. You might find that some will specify "euro" or "USA" ranges, so you may have to assume which yours will be.

I presume, but could do with confirmation, that the alternator output is used to pulse the tachometer, probably via a capacitor within the Logic Combi.

Normally a connection from the "W" terminal on the alternator.
 
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Your engine should use standard 180 ohm resistance gauges. This can be checked with a multimeter easily if you are in doubt. I completed an install on a twin Yanmar mobo with same combi screen as you have. This was in addition to the existing instrumentation so the plotter would display all the engine and tank parameters and look smart.

I have a slow ongoing developmental install on my motorboat boat which was initially going to be an Actisense EMU but in the end moved to a MIMO Alba ethernet interface which along with iKommunicate provides data & stuff - everything available anywhere. Very unnecessary but very cool.
 
Unfortunately our boat is in Southern Brittany, and so experimentation and taking measurements is awkward, and we cannot operate without something in its place, so I'd like to go prepared.

Your engine should use standard 180 ohm resistance gauges. This can be checked with a multimeter easily if you are in doubt.

Try and keep up at the back :)
 
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