SF800_flowmeter

This project shows the implementation of a liquid flowmeter using the SF800 flow transducer and the mbed. The Swissflow SF800 directly senses volumetric flow using a simple rotor chopping an IR beam. A hook up diagram is shown below.

/media/uploads/daveTshave/sf800_-_hook_up.jpg

The follow connections to the mbed are made:

line 2 connected to Vout pin via a 250 Ohm resistor (Rs)

line | connected to Pin 29

line 1 connected to to GND pin

Pin 29 and Vout are shorted through 2200 Ohm resistor

The following library and example application can be used to follow the flow rate using the USB serial connection from a PC. The mbed integrates the pulses over a ten second window. Two windows are used and are staggered by 5 seconds to ensure a continuous, noise free, response. Since the counter is not reset the program will presumably crash after a sufficiently long period of time has elapsed due to an overflow. We have not observed this during the timescales over which we are measuring.

Import librarycounter


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