VDO sender in the tank, 0-90 ohm range.
200 ohm pullup resistor from +5v to A1, as it’s the lowest value I have here.
Ran a sensor ground and A1 to the sender in the tank.
I Set A1 as a calibrated sensor in software, enabled 10k pullup in software.
Drained tank then added 5l of fuel, the reading did not change.
Added a further 5l into the tank and the reading still did not change.
In the graph log, after adding A1 to it, it is greyed out and does not change when changing between software selectable pullup or pulldown.
I have checked the wiring, as always this is the first thing, and it is wired correctly.
What do you think?
Resistor too high?
Settings incorrect?
Sender no good?
Thank you Greg, I tried that as well and still no reading change and ADU 1 voltage greyed out on graph log at ~1.0v.
I realised I do have lower value resistors here, obviously have 120 ohm for CAN use, would this be better? I am not sure how low we can go before it is an issue for the ADU output, current wise.
Thanks Greg, quick one, my fuel level seems to be reading now, although it has a very small voltage swing of about 1.55v at full and 0.74v at empty.
I have the tank level filtering source as the analogue input, and have the fuel level bar graph source as ecu.fuel level or however it is named, it seems to display correctly as a bar and the bar markers are correct, but the displayed text value on the bar is in % and not Litres and there is no option to change it.
edit. Seems odd using ecu.fuel… as the output channel from the filtering, but I think you said in previous topics for other people that this is correct even when not using the actual ECU as the source?
How small can you go before it’s an issue, current wise?
200 ohm is already pretty small in the scale of things, isn’t it.
Going with a typical half of the resistance rule of thumb is going to result in a ~40 ohm resistor, is the ADU going to like that? I have a 39 ohm but is it going to get warm?
Also the % instead of litres is a minor detail, but is there a workaround?
100 ohms is safe, I’ve gone as low as 20 ohms without issue. Granted fuel level was the only 5V sensor on that build.
Yes it uses ecu.fuel as the output from the filtering parameter. It’s just a channel name.
If you want to change the channel name and log in Litres but maintain the filtering you can create a number channel that will convert the units to Litres. And when I say convert i mean literally just takes the value from ecu.fuel and displays as litres, since I think that’s how you’ve calculated it.
Just stuck a 39 ohm in it, no other sensors powered by the dash, with no plan for future expansion (although I do have a spare input/output connector on the loom).
