Thread: Fusion Brain CarPC LT1 dash gauges project

Edited first post with higher 12V battery voltage resistor values, corrected oil pressure values. Increased resistor values for fuel and oil pressure gauges to reduce current.

Alternator check light I'm going to replace with a relay to deal with the 12V reversing polarity. I trust there is no issue connecting FB 5V out directly to the AIN for on/off input.

The service engine light goes to ground but can have up to 0.5V when not activated. I was thinking 5V out, 100K, AIN & 10K voltage divider connected to a diode and the signal wire.

I've had some success. The gutted and epoxied in water temp sensor is working. I clipped off the capacitor as was suggested for over 105*C.
Voltage gauge is working with some tuning to match my multi-meter reading.
Alternator light with relay works after trial and error with resistor values.
Check engine light worked as planned though values are lower than expected.
Oil sensor seems to work, but I have either a bad sender or no pressure. Ordered replacement sender.
Outside temp was plug and play.
Chickened out on rotation images in MDX and went digital. Created a large numbers font for speedo because the existing verdana got blurry.
Need to order more input cables and a couple frequency-to-voltage converters. Will need at least one more FB to run all my idiot lights.

Questions: The empty ports are reading at least 0.2V. Port0 is pulling 0.96V from somewhere pegging out my tach with nothing hooked to it. Where are the free electrons coming from?
I contacted the FB guys about a quote modifying their Freq-to-V board for more resolution. While I wait for a reply, has anyone located something off the shelf elsewhere? My math says 1V will be 132MPH and 8600RPM if I hook up the FB converters.

You can zero out the unused ports with a jumper from "-" to "AN". They red voltage because the PIC microprocessor really only has one analog to digital converter, and it switches from port to port. There is some residual charge in the internal sample and hold capacitor.

Sorry we haven't had a chance to respond to your email, but we can modify those boards for the price of parts. Email us with exactly what you want.

Every once in great while I get lucky. New oil pressure sender working! Wife thought I passed out in car as I sat watching my gauges. Wondering why I couldn't use another one of these senders for fuel pressure? Worst case fire and explosion. Can't think of a material that would survive hot oil but not cool gas at same pressures.

I'm going to try tapping MAP sensor signal wire (0.2-4.9V) directly for vacuum boost gauge on second FB. I've finished skinning idiot lights and gauges for my dash except odometer. Only suggestion I've gotten was flames when speed hits 88 mph (just got Back to the Future reference).

Got quote today for modified Hz to V boards. Need more parts!

Thanks. Welcome to it.

Get anywhere on read/writing variable data to a file? Just starting to ponder an odometer. 100mph, 4000 pulses per mile: 111.111Hz. Usually slower.

Originally Posted by ACCLR8N

Wondering why I couldn't use another one of these senders for fuel pressure? Worst case fire and explosion. Can't think of a material that would survive hot oil but not cool gas at same pressures.

Contact the mfgr. Some sensors are interchangeable, some are not. Gasoline breaks down certain rubbers.

You have a PM..