I am working on a project for school where I am making a machine to pour mixed drinks. I want to control the flow of liquids using a servo, which is connected to 9 buttons(3 different liquids with 3 different ounce amounts). Essentially, the servo will open and close a valve allowing the liquid to flow. Leaving the fluid dynamics aside of calculating how long I should have the valve open to get specific ounce amounts, what is a good place to start creating such a device? I have access a large variety of parts and tools, but don't have a lot of programming experience. I am willing to learn however. Any advice you may have will be much appreciated.

 

You could do it several ways:

1. PICAXE, uC, free programming tool.
2. MikroC, uC, free programming tool.
3. MPLAB, uC, free programming tool.

I guess the list is almost endless....


These three requires some extra hardware and software, and the time to learn/program the uC.

There are several more ways to to this, what were your plans?

 

Well I need to have this finished in two weeks time. Other than that, I am pretty open to whatever way is the easiest and will allow me to get this done efficiently.

I'm going through the links you put up and am now only more confused. I believe what I'm trying to do is relatively simple, so I shouldn't need too much processing power, but I don't know what that translates to in terms of a uC or anything. Could you possibly post a link to a specific uC that you think would be good for me to use?

 

I think, I'm many sure will disagree, that PICAXE is suitable and up for the task.

The 14M2, is more than good enough, I think.

You can download free programming software here.

And check out page 19 in this document.

A little warning: I'm not a mastermind of uC or programming, and I'm still learning.

 

You could do it with a few 555 timers. The 555 is wired as a "monostable" and when its button is pressed it turns the valve on for X seconds. The time for each 555 is adjustable via a trimpot.

 

I've worked with PICAXEs a bit and think that would be a great choice. That said, with only 2 weeks to complete, I would go with Roman's suggestion of 555's. Easy to replicate 9 timers. Or, 3 timers and a matrix of 9 switches.
Oops...and one as a servo pulse oscillator.

Ken