I am having trouble doing the calculation for RlCl for this F/V converter circuit.

The supply voltage will be between 11.9 and 15 V (stabilized to 12VDC), the input frequency from 0-1Khz and necessary output voltage for Teensy use will be 0-5V (with R divider) or even better 0-3.3V.

According to the datasheet I have to calculate the resistance of Rl and the capacity of Cl.

The attached image shows the default circuit for 0-10Khz full scale.

Could any help me choosing the right components for 12V supply Voltage, input frequency 0-1Khz and output voltage 0-3.3V (or 0-5V if necessary)?

no, unfortunately not. Even if I use Teensy it is to unstable to count the impulses directly with a refresh interval of 1 second. This due to the huge range. The times will get to big to get an accurate result. If I rember right it was an error abour ± 30% depending on the situation.
Since I need to count to values and subtract them this will not work.

The question was something completely different and of course you can if you read the datasheet.
RC and the others resistors declare the range of output voltage and the input range of frequency.

autopilotNOR:
no, unfortunately not. Even if I use Teensy it is to unstable to count the impulses directly with a refresh interval of 1 second. This due to the huge range.

BS.

Need to study how frequency couters work.
There are AFAIK two ways.

Count pulses (state changes) for a fixed amount of time.

measure time between state changes (used for very low frequencies).
Leo..