Auto Lemonade Maker :D :D

[chickens1127]

Summer has arrived in the very hot area of the Mid-Atlantic. Although we get 30+ inches, sometimes 50+ a year, we also always have 5 100+ days and nearly all days are above 90 F with at least 40% humidity. You'd never know from a map. Anyways, to my point.

Like most teenagers, I want more money. (Particulary video games, electronic parts, and most importantly, airsoft gear.) So, instead of sitting outside seven hours every day all summer selling lemonade, and making very little money, and having the most boring summer going into highschool. I am attempting to make a full-auto lemonade machine. This way, I put signs on my road to turn off, and then they can get a refreshing cup of lemonade while I'm at the mall or at a camp.

So, I've come up with a design, with a large water resevoir, connected to some electronic valve(electronic sprinker valve? are these cheap? or some type of electronic liquid valve, and do the same with a highly concentrated lemon mixture, and hook both up to maybe a PIC microcontroller(Can I have a link to a serial programmer) so it can say, run electricty to the water tank for 0.3 seconds, and 0.08 for the lemon mixture. The only thing the customer has to do is take a cup and put it underneath.

A couple questions besides the few up here:
1: Is there any good DIV electronic coin op plans?
2. I know this, but for verification. With a PIC chip, would I need an oscillator or anything else? I doubt it, but not sure. I only have 'duino experience which is out of my price range for this project.


Thanks and sorry for all the questions

 

[chickens1127]

No help???

 

[Sceadwian]

Why mix the liquid in the device? Why not just dispense directly from a single main tank? Much simpler setup. You use a servo or stepper motor to control a water valve but the exact type of valve would be a little tricky to avoid spillage, go browsing in the plumbing department of a hardware store to see what you can find/. Maybe an ultrasonic sensor to determine the liquid level in the cup. Just a few ideas. The coin parts is actually harder, I think they're usually done by basic sizing and possibly weight.

 

[Birdman Adam]

Yea...Having it dispense from a large container of pre-mixed lemonade would be much easier to implement!

1. It should be able to sense if there is lemonade left, and if not, have some type of signal on to show the customer, and not accept money. This should be pretty easy to implement.

2. I would turn on the valve or pump for a pre-set amount of time, instead of measuring the liquid in the cup. Again, easier to implement. You can just time how long it takes to fill the cups you set out, and put that in your code. You could even have small, medium, and large amounts.

3. Here are some links to two great designs that you can make at home for coin slot & detection:

DIY Coin Mechanism for vending machine II
DIY Coin Mechanism for Vending Machine III

All you will need to do is add a little switch where the guy says, and wire that to your microcontroller. I don't know what the cost of a cup of lemonade would be, but his second design only lets quarters through, and the third design only lets nickels through. Any other values are dumped to a little box where the customer can take the coin back out.

4. As far as microcontrollers, you shouldn't need any external oscillator, as almost all pics already have an internal one that is used by default. All your really doing is sensing a switch, turning on/off a port for a certain amount of time, and sensing if there is lemonade left.