I know almost nothing about electronics, but I'm trying to learn.
I need your guidance on this one, because it's still out of my understanding.
As my very first project, I'm doing a motorcycle dashboard, including the speedometer and the fuel indicator amongst other things.
if i'm not wrong, the fuel gauge, it is a variable resistance, that I should be able to read with analogRead. the problem is that, knowing nothing about electronics, i'm afraid I might blow up my Mega(and here in Argentina it's not easy to replace it).
Trying to read the value of the resistance using a tester(please correct me if it's not the right name) ,it says 9,8 ohms at almost full (again, i might be wrong). So, before plugging the arduino pins to this, I tried plugging 5v at one end, and a voltage tester at the other end, to read how much of the 5v gets trough the variable resistance. Something went wrong, because the power source turned off, like if there is a short circuit (wich is probably what happened) . I'm using a branded cellphone car charger as power, since it seems quite good at converting 12v from the motorcycle battery, to the 5v needed for the usb, and the label reads 800mah.
My question is how could i safely read this, without killing my board? is 10 ohm a very low value for a fuel indicator? Googling other projects, they had higher values, am i reading wrong? my idea is to apply 5v trough this, and read the analog value on the other end, to get an approximate of the remaining fuel.
I can add more detail if something it's not clear, but that's the idea.
Please excuse my poor english, and thanks in advance for reading.