digital tachometer signal produced by my car
Show us a schematic of the existing wiring. Also images of the wiring if you can.
Can you supply a drawing of the Are you working from the CAN-BUS or some other tachometer signal?How does the signal change as the revs change?
Its unlikely that a signal from a digital device to another would use an analog voltage. From your description I'd guess its a frequency, or PWM.How you process it would depend on the actual signal. However you could try this as an experimenthttps://www.instructables.com/Analog-Output-Convert-PWM-to-Voltage/can you get an oscilloscope to look at the signal?
Ferrite clamps can just be considered as inductors because that is what they are. So if you want to replace them then you could use an inductor in seriese with your power cable. In addition you can use a capacitor to ground on the Arduino side of the inductor. Use a big capacitor like a 1000uF and in parallel with it put a 0.1uF ceramic capacitor. To increase the filtering repeat this circuit in series with the last.I would even include those clamps and explain they are inductors and as such normal components. They are not exotic stuff like transorbs.
Ferrite sleeves at higher frequencies (VHF) are often fairly lossy inductors, which is even betteras interference is largely absorbed rather than reflected back at its source.
describe, I would run the power from the car, through the LC circuit, and then to the Arduino?
If so, I'm using the USB port to power the board, so how difficult would it be to accomplish this?
So far I've been able to run the signal through a voltage divider to a digital pin on the board. I wrote a shell of a code to display the values and I took it out to test it. The RPM displayed at idle is accurate, however when I rev the engine or drive it, the error in the displayed value gets worse as the RPM gets higher.
The RPM displayed at idle is accurate