 # How to read 0volts to 14Volts in analog input arduino uno?It's possible?

I'm trying to develop a speedometer for my car, using the vss signal (Velocity speed sensor), with CI LM2907/2917 (Frequency to voltage converter), but starting from 83km / h 5.03 Volts. how I use the analog input of the Arduino to read voltage above 5volts? When you reach 220Km/h the voltage is 13.33 volts. Can someone help me?

You use a potential divider ( two resistors ) to cut down the voltage so that with maximum voltage you only get 5V at the arduino input.

You use a potential divider ( two resistors ) to cut down the voltage so that with maximum voltage you only get 5V at the arduino input.

I use the analog input of the Arduino to read voltage above 5volts? When you reach 220Km/h the voltage is 13.33 volts.
Can someone help me?

–[VIN -----[ 100k resistor]— --------------------------------------> >-----(Arduino analog input)
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[47 k ohm]
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V (GND)

Resistors too large.

Effective input impedance of the Arduino input in analog mode is of the order of 10k - and probably not constant because it depends on how rapidly you sample.

First approximation (probably sufficient), use 10k and 4k7. If you want more accuracy, buffer it with an op-amp.

buffer it with an op-amp.

That's OP AMP VOLTAGE FOLLOWER for you OP AMP challenged folks ..... XD

Thank you, raschemmel was what I was thinking of doing. I think it will work that way. :grin:

thank you Grumpy Mike for help.

You should be able to use a pot as an adjustable voltage divider to set the input voltage to the arduino as desired .

You should be able to use a pot as an adjustable voltage divider to set the input voltage to the arduino as desired .

10k to 20 k would probably be the best range.