I was inspired to make a barbot after seeing some similar projects on Youtube. The skill level and the amount of parts of most barbots made me think I could simplify this by using pumps. Other design using pumps are pumping very slowly (over a minute to mix a small drink) and the pumps I use are great for the application.

I already made a large Cocktail machine but it was very bulky and the flow meter bugged out. This machine worked with Alexa (using an alexa enabled IR sender for TV's and an Arduino Mega with an IR receiver very sketchy and hacky).  If you wanted to see how it works you can check this out. 

So this was one year ago and 6 months ago I scraped it for parts because it took long to set-up and to clean. So I had all these pumps laying around. During the lockdown I wanted to make a project and worked with the things I got laying around. This time using a Bluetooth module and writing an app in the MIT app inventor software (free, easy to use an awesome!).  

If you wan't a quick view of the build you can view this video:

Making this project I also kept in mind the need of solid code and good comments so you can change the project to mix the drinks you want.

So I first started out by making a frame out of some wood panels that I had laying around. I cut 4 pieces of 16, 5cm x 33cm (6, 5 inch x 13 inch) and connected two of them with screws together like you see in the picture below:

Then I cut a another piece of wood to the dimension of the inner side of the square when you would connect all plates together we cut previously. And drilled some holes in it with the 28mm drillbit. Make sure the centre of the holes are 5cm (2 inches) spaced out so you have enough room for the pumps there.

I screwed together the plates like you can see in the picture. Make sure you use a small drill to predrill the holes for the screws. This will help stop the wood from splitting.

Then it was time for connecting the Arduino Uno with the Bluetooth module and the relay board. You don't have to connect the pumps. Use the wire schematic to do so.

We wan't to check if the circuit of the relay board, Bluetooth module and the Arduino Uno work. So after this download the code to the Arduino Uno.

So now I should recommend testing the circuit. First you should download the app and connect the Bluetooth module. Make sure the Bluetooth module is powered on and is blinking.

Then follow this video guide:

Pleas note that I made the app so that you have to press for a longer time on a button to make sure accidents stay at a minimum. So push the buttons for 2-3 seconds.

So when pressing a cocktail you should hear the relays turn on and off. You can also check the lamps on the relay board. A good way to test all pumps is to run the cleaning program. Each relay should be activated for 5 seconds each one by one.

You should solder on the capacitor of 1qF. You have to do this because otherwise the radio frequency noise of brushes of the DC motor will cause the Bluetooth module to disconnect and other stuff you do not want.

The soldering of the wires should be done in a later step not this step
The soldering of the wires should be done in a later step not this step

After this you can connect the power supply and the pump. Put the pumps in the holes we drilled earlier. To do so you have to remove the extra round shielding component. This snaps of easy. Keep one aside because we gone use it later.

No you can connect the power supply, relay board and pumps together using the wiring diagram. After this you can check with the app if the pumps are working. If you have problems with the Bluetooth communication you should check if any of the capacitors is came loose.

Then you can start setting things up to make real drinks. First I suggest to clean all the pumps. You should get a large pitcher or a a bucket with clean water and put all the suction hoses in the bucket. On the pressure side of the hoses (where later the cocktail glasses go) you should also put an...

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