Can any one tell me what I would need or any useful links to find out how to combine a Credit card payment system and link it to a liquid flow meter, which allows a certain amount of liquid to flow depending on what is paid for.

 

Hi,

Credit card readers are very common. The output is ASCII. The rest of the device is going to be a microprocessor that calls and verifies the card, debits the charge, and then dispenses the liquid. If this is going to be a business application, be sure the State and Federal Weight & Measures people are going to be happy with the acuracy of the quantity dispensed.

Gas pumps do this all the time, although the dispensed quantity is usually charged after the transfer.