Hi,
The motor is a 3 phase BLDC motor with 4 pole pairs and 3 inbuilt hall effect sensors. I know it can easily be done using an arduino, but I wanna build an electronic circuit without the Arduino to measure rpm of the motor. You asked me what I want to use, but that's what I need help to figure out. Is there a way to do this using an integrator?
The PI controller isn't finalized yet.
Still the hall sensor signal are not clear. You know an electrical signal is defined with: volts, current, power supply, frequency...and so on
With all this being undefined your question is similar to ask for the price to travel to your uncle.
* it's not defined where to start (undefined motor)
* it's not defined where your uncle lives (undefined PI controller)
* it's not defined what vehicle to use, like car, ship, aeroplane (undefined signals)
There are many different ways to travel. And there are many different ways to build a motor controller system.
The motor should be clear. And it has a datasheet with all the necessary motor informations.
Then you need to decide which power stage and which speed controller to choose. You need to decide what parameters are important for you. Voltage and current need to meet the motor specifications, but with others like: cost, size, power dissipation, precision, self made vs ready to buy, time to market .... we can't help you.
Then you will see which input signals it needs. It may be analog, it may be digital. There are many controller modules already have built in the hall interface, then it'just the cabling you need. No need to worry about an integrator...
I recommend to look for similar projects in the internet. Look how they made it. Find out what you need.
Klaus