June 11, 2006

Most of my day today was spent messing about with the EFIS 1, and getting all my engine gauges working as they should. I needed to get the ammeter working properly, which meant moving the input from one of the fuel senders to a different pin. Reason for this is that there are only three 10v voltage inputs on the E1, and I have them all used up! I have the fuel senders into two of them, and the voltmeter into the other.

There are a whole bunch of resistive inputs in the E1, that from the factory come as voltage inputs. To make them resistive, you have to install a jumper. These only accept 1.67v though, so in order to make it all work out some thinking was in order!

The current sensor from Blue Mountain outputs 5v when the current is close to zero amps, and it comes with a calibration table to input into the sensor map to calibrate it correctly. This means that it would be best for me to use one of the 10v inputs, otherwise I’d have to spend a bunch of time messing with the calibration. Something I didn’t really feel like doing.

The answer was to move one of the fuel sender wires to the 1.67v input and then use a 10v input for the current sensor. All would be good. My fuel senders send out up to 5v too though, but I could easily make a voltage divider to bring this down to an acceptable level. That’s basically what I did. It’s a lot easier to calibrate a fuel gauge than mess around calibrating my ammeter with a multimeter!

I also loaded the calibration array for the Floscan fuel flow meter. I hadn’t done this yet, so I was getting all sorts of wacky numbers for fuel flow! I use a 201B sensor, and there’s a pre-loaded cal array in the E1 just for that.

The E1 used to display OAT on the ADI part of the screen by the true airspeed number. I notice that this has now gone, so I decided to add that to the engine gauge page.

I ran the plane a couple of times today too, to confirm everything was good. Fuel flows around 2gph while sitting on the ground, and the ammeter works fine now too. We now have 0.8 hours on the engine. Sweet.

I’m almost ready to put that top forward skin on! I need to pluck up some courage though first!

I also put the taxi light in. I didn’t bother putting it on the wings page, as it was just a trivial 5 minute thing, and it’s the same as the landing light. I just figured I’d log it here for good measure.