Fuel tank level clibration

[microflying]

Have been calibrating the fuel tank sensors with the Dynon today on my sportcruiser, unsuccessfully.
Followed instructions as per the manual, adding 5lts. at a time as per the calculated display request . The left tank sensor did not register any of the additions but carried on any way to see what the finished result would be. At the end message came up "tank calibration unsuccessful do you want to use anyway" accepted that but as expected calibration is not working. Fuel was drained out and display is still reading 50lts.
Tried again on right tank but again most of the fuel additions were not recognised though different to left tank the sensor did read some of the additions. Again message came up "tank calibration unsuccessful do you want to use anyway" accepted that but different to left tank the display is reading "0" evn though there is still 50lts. in there.
The black wire out from the sensor should be making a good earth. Riveted it to the internal of the wing root making sure it made good contact. Blue wires went to pins 20 and 21 respectively.
Any ideas what could be wrong?

 

[DBRV10]

OK My post is removed........ I was wrong!

DB  

 

[dynonsupport]

Most fuel level floats are resistive to ground. Thus they need NO pull up to 5V. We do that inside the unit, so you don't have to do it outside. You do need to make sure you have the fuel level input set as "resistive" not "capacitive"

As it says in the manual:
"You may connect up to four resistive fuel level sensors to the FlightDEK-D180. Simply connect the output of the sensor you would like to be Fuel Level 1 (left tank) to pin 20 and the sensor you
would like to be Fuel Level 2 (right tank) to pin 21."

We mean it when we say it. Hook it up, no external components needed.

If you are getting no motion on the fuel sender, then you should probably check resistance by hand. Disconnect the fuel sender output from the EMS, and measure resistance to ground. It should vary from near zero to up to around 220 ohms. It may only go to 90, which is fine. You'll need to move the sender somehow.

If it does that, then make sure your wiring is fully intact to the EMS. If it is intact, and the EMS is set to "resistive," then the EMS is broken, but we've never once seen that failure

 

[DBRV10]

I must have been thinking of this bit where the analogues get used for extra fuel and things like trim and flap positions

Silly me.... :


FUEL LEVEL (RESISTIVE) SENSORS
You may connect up to two resistive fuel level sensors to the GP inputs. Generally, this should only be done if the plane has more than two tanks and the dedicated fuel level inputs are already used. Connect the output of the fuel level sensor to the desired GP input. Also, connect this same node to a 1k[ch937] resistor (color bands: brown, black, black, brown, brown; connect in either direction); the other end of which should be attached to the +5V Excitation Circuit.
Be sure to configure the firmware to recognize the fuel level sensor on the general-purpose input(s) you’ve chosen as described in the General Purpose Inputs section on page 5-16.