There are at least two optional wiring schemes for the one PicAXE
per injector EFI system.

The PicAXE could be mounted on the injector
or it could be plugged into a mother board bus located
behind the instrument panel. That would give you the option
of using one mass air flow sensor to cut about $30 each
from the PicAXE parts cost. It would also reduce a bunch
of wires floating around the engine compartment. The leaning
pot could be attached to the motor board. So too the
USB connector for the removable cockpit PC.

What do you people think ?

Here too is the Omega temperature data acquisition RS232 net work
system for the addition of EGT and other temperatures monitors.
Of course they will require one off the shelf low cost RS232 to
USB adapter as will the RS232 PicAXE's. This adapter can be mounted
on the mother board. Data display and formating is up to the PC.
-- 
Paul Lamar ...No rotor no motor.

Hi Paul,
The motherboard bus offers fewer wires cris-crossing the engine and
therefore less opportunity for wire damage and stray electrical noise
pickup. Also trouble shooting will be easier with only two wires per
injector to check for activity, if those wires check out then the
motherboard bus could be removed for troubleshooting comfortably at a
bench rather than hanging into an engine bay trying to figure out
exactly which wire is from where when the real problem could be a simple
solder joint failure. Does anyone see advantages to the injector mounted
concept?        Dave M


I agree.

I might add there is another advantage to the bus approach.
A spare PicAXE can be carried and exchanged in the air if one
PicAXE fails assuming you are high enough and have the required time
of course.

I might also add that the RS485 interface system could be implemented.
This is a balanced line, twisted pair interface system with
reduced susceptibility to electrical noise compared to RS232 systems.
There are chips that convert RS232 to RS485.

Paul Lamar ...No rotor no motor.

I love this group of optimists.  on one hand there is a seasoned electrical
engineer giving seminars and selling books pushing for fuses over circuit
breakers because you don't have time in the air to debug electrical
problems, and another says hey, you could always swap motherboards if you
had time and altitude.  i'm not criticising anyone, just laughing at
ourselves! :-)  i personally don't have a gyro, knowing it might encourage
me to fly in crap i shouldn't be in.  the wing leveler would be my last
ditch, and i don't really trust it that much (it lets go sometimes)  if we
can drive and talk on a cell phone, we probably can even reprogram the chip
on the go  (damn, i would have guessed we could have made it :-)    kevin

Reprogramming the chips in the air is exactly what Tracy wants
wants us to do :)

I am not advocating swapping the mother board. Just one injector computer.
The engine will still run with one injector shut down.