Calibration of flow sensor

Hello guys,
I am working on a project with inhalers. I have to put flow sensors in the inhaler. I am using Honeywell HAF series sensor with 50 SLPM. the problem is when I run the code the flow rate value changes and then sticks to a constant value and doesn’t go to its full-scale value.
Please help me.
Please find the attached code.
Best Regards
Rohit Nehra

final_code.ino (5.63 KB)

This looks like a electronic problem. Please provide a circuit diagram, and a link to the sensor data sheet.

  1. Link of datasheet;

  2. circuit diagram I am using a multiplexer TCA9548A and connects the flow sensor at SD5, SC5 and SD4, SC4. I provided the power supply 3.3V and 5v but still doesn't work.

The data sheet indicates 3V digital operation, that's not the usual 3.3V. Did you add pullups to 3V?

If that doesn't help, a circuit diagram is required.