Dear mirip,

So sorry I can't give you the answer if your program is good. Most of the time I can't follow my own logic when I go back to my old programs :-( andyours looks complicated for arelatively simple task.I have couple of comments though:

• If I had to weigh liquid I would use a mass flow meter with pulse output.If you use flow rate, there is no way of knowing what happens between any two measurements (I believe you take a sample every 0.5s).
• You may consider using a timed interrupt rather than a timer to take samples. It will make measurement a little more precise.
• You may also consider using two valves (one large, one small) and keep only small one open towards the end to increase dispensing accuracy. You will overhoot each timewhen you give signal to close the valve but at least it will be less if the flow rate is slower.

Hope it helps.