Based on RandA, prepares cocktails from special dispensers quantities of beverages provided by stored recipes from the web page from which you require the preparation. Drink Maker, available in version to be mounted, is suitable for those who want to make their home a corner bar technology and amaze your friends by making them "order" smartphone or PC to prepare your favorite cocktail and seeing live from the robot. Our robotic machine prepares-beverage is a frame composed of aluminum profiles, on which are applied in a row of the dispenser with push-button actuating rear, pressed by a lever controlled by a servomotor; each dispenser (or dispenser, or tapster, if you like) every time it presses the drive delivers a predetermined quantity of beverage, which in our case corresponds to 2 cc (20 ml). The dispensers are mounted each on a bottle holder which allows to slip on the nozzle to seal in the neck of the bottle and make the stable set.

Everything is on the top unit of the machine, fixed to the base on which the trolley runs linearly on the axis glass, which flows through the ball caster quarries of aluminium profiles are longer than the frame; behind the cart it is also fixed the actuator which actuates the dispenser, so every time that the glass is carried by the carriage under a dispenser, this is actuated and pays its dose for the number of times set by the system. To avoid that in the movement from a dispenser to the other cocktail is shaken so as to go out from the glass, we made sure that the carriage several progressively its slow starting speed, reaching about one second after the maximum speed, then slowing down to a stop , in another second. The movement of the trolley is obtained by means of a toothed belt which engages in a pulley, which is also toothed, driven by a stepper motor in the lower part of the frame; the engine is run by a dedicated controller and aligned at the start on the basis of a limit switch placed to the left stop, which is energized by a special projection of the carriage. The beginning of the stroke of the carriage fits over the first dispenser, thus in phase of construction of the machine must ensure that you put the switch limit switch so that its lever is pressed when the trolley has the glass centered relative to the nozzle of the first dispenser.

In order that the mechanics can accomplish as just described, that is to say bring the cart with the glass beneath the bottles needed to prepare the cocktail required and to receive from the amount of drink dispenser provided, it takes a fairly sophisticated electronic control, which in our case is obtained combining Raspberry Pi, our board RandA (bridge between Raspberry Pi and Arduino), a specific shield and a motor driver, who then is the same used in the design of the 3D printer 3Drag. The whole sequence of movements necessary to prepare a cocktail and bring the glass containing it to start the car to be taken, is decided on the basis of the composition of the same cocktails, selected by the user via a web interface customizable. So we have a part of the electronics that allows you to choose the cocktail in a database (previously prepared by the transmission system and modular at will), another that translates the ingredients of cocktails in the same movements of the mechanical (moving cart, press the button dispenser ...) and another that controls physically -following the corrispondent instructions- the stepper motor and the actuator to operate appropriate action.

Attention! the DrinkMaker includes only 5 dispensers, because it is able to support and manage up to a max. of 10. The package includes everything you need, electronics and components, to achieve DrinkMaker in version 5 dispensers.

The basic structure is made of aluminum profiles framework by 27,5x27,5 mm and L from 29,5x53,6x2,4 mm (full details of the design, the files for processing parts with CNC and those printed in 3D making up some details are available on the site www.elettronicain.it). The frame itself consists of two sections from each 27,5x27,5 mm long 1 meter, it joined by a frame to the side, made with the same profile but the size of 150 mm (base) to 330 mm (height). In fact, the profiles that are on the back of the frames are high 600 mm. The assembly of the parts is made via screws, closing each end with plugs from 27,5x27,5 mm. On the front of the top unit must be applied to the screw at a distance of 97.7 mm from each other, the support brackets of the bottles, the bases of which must fix the dispensers with the screws; the bracket further to the left must be exact to 60 mm from the inner side of the upright section member constituted by a square section from 27,5x27,5x600 mm.
The cart is a plate of aluminum from 192x100 mm, thickness 3 mm, suitably machined with a CNC milling machine, which is applied a plexiglass plate of equal dimensions, machined to be screwed to the aluminum plate below and to accommodate the plate glass door and the eventual LED ring. At the bottom of the carriage, on the short sides, should apply two ball-caster with ball 10mm that you can buy on www.futurashop.it with code PBCASTER38 and serving to slide the cart itself along the hollow of the profiled by 1 meter. The ball-caster must be positioned at a distance from the edges of the aluminum plate that can slide in the quarries. The movement of the carriage is obtained by fixing the toothed belt, cut to size and passed around the free pulley of the right side and that of the stepper motor, to a suitable support to be screwed below the aluminum plate; the same support, as well as to stop the belt with a screw, serves to move the switch lever limit switch; the position will be chosen considering that the switch must be pressed when the truck is all beginning. To avoid spillage from lifting of the trolley, to the section bars 1 meter apply two aluminum profiles at right angles of equal length, from 29,5x53,6x2,4 mm, namely with the edge on the outside.

The electronic board is composed of Raspberry Pi which is applied over the mainsail sheet, which houses the shield; the whole thing was planned to be placed in a plastic printed in 3D (with our 3Drag, if you have at home ...) in which you insert a small fan for cooling to 12 V. If you apply the LED ring! Make pass the cable underneath the plate and secure with special staples, the same to be used to stop the LED strip on the rear L profile. Arrange the parts, you need to apply power, recalling that need a power supply 12 VDC - 2.5 A for the shield and one 5 V, 1.5 A for Randa (and through the lower strip feeds Raspberry Pi); the cables of the two must be applied to the respective connections to the terminal block. The sketch of Randa is programmed via the IDE changed, downloadable from our website www.elettronicain.it, which allows for loading across the network, from Raspberry Pi, so you must connect it to a networked PC. If you want to add to your Drink Maker the strip LED (optional), you should plan for it a special power supply from 5V 1.5A; Ring LED (optional) is instead powered directly by Randa. Before applying the shield to Randa, you must open the jumper J2 on the latter, which is normally used to allow the Arduino logic on-board switching on and off Raspberry Pi. In this application must be open, also because the line D4 Arduino is used through the shield- to handle the enable input of the engine controller. Note that before using the system may need to adjust the trimmer miniature controller motors; in order to make sure that the power supply is turned on and connected to the board, take the multimeter and a screwdriver tiny ceramic (you can also use a metal screwdriver, but in this case must be very careful to touch only the trimmer of the driver to avoid short out) then set the multimeter in the range 2 V DC or similar. Keep the black lead connected to the negative terminal of the power adapter and the red lead on the pad placed over the chip driver. Use a screwdriver to adjust the ceramic trimmer driver to read on the multimeter voltage of 0.425 V. After that you can remove the tester and turn off the power, then close the box containing the electronics.

• Raspberry Pi creates and governs the web user interface, serves as host for the settings of the cocktail, manages auxiliary functions such as verification of the order based on the availability of the ingredients making up the cocktail (holding memory counting, known capacity bottle of each dispenser), then for each product prepares the set of commands for positioning and activation of the button of the dispenser which then passes to the section Arduino.
• RandA, which contains the hardware Arduino One and the interconnections with Raspberry Pi, receives from the instructions for preparation of the cocktail in progress, that is to say the position request and the command of the button opening of the dispenser, converts them into direct commands to the motor driver (pulse control) and servo control, and gives the commands of the case in the appropriate sequence.
• The shield interface RandA with the connections of the stepper motor and servo control, but also those with light-signaling devices (this will be discussed shortly), the limit switches and the like, as well as hosting the engine driver.
• The engine driver, based on the pulses received from RandA, drives the stepper motor to advance it in the number of steps required

The software provides the firmware to be loaded in the mainsail and the software itself, which takes place in Raspberry Pi and turn on it. This program consists of a database, and also an user interface divided into two parts:
- a front-end, consisting of the web pagethat the users sees ponting the IP address of Raspberry Pi and on which work to order.
- a back-end (admin) managed by the system administrator and trasparent to the user.
 

The electronic steering the car cocktails and interface to computer-based Raspberry Pi and RandA. RandA (contraction of the words Raspberry and Arduino) is a board for Raspberry Pi with Atmel processor 328, RTC (Real Time Clock), power button and sleep timer, two power connectors to 5 Volt (a micro USB and a terminal block) and side connectors compatible with the Arduino shield on the upper side, and the lower part a connector for the graft on the connection GPIO of Raspberry Pi. RandA substantially contains the hardware Arduino Uno private section of the power and the USB communication port, but with the added RTC. RandA leverages the hardware equipment and the enormous potential of the Linux platform Raspberry Pi and the amount of shield and Arduino sketch for the world. The link between the two platforms is made through connector Raspberry Pi, which RandA is attached only to the top 20: this allows you to use both RandA on Raspberry Pi Raspberry Pi on that B + B. The serial port is used for both programming Arduino both for communication with Raspberry Pi. In the application of these pages, Raspberry Pi uses Arduino as configurable device, whose program is chosen to handle motors and sensors of the machine, following the orders of the Raspberry Pi and returned to the state. Availability RTC onboard RandA would turn Raspberry Pi and Arduino at scheduled times, but in this case we do not need this function; we do not exploit even the ability to turn on Raspberry Pi by RandA, because the responsible line (D4) is already earmarked for the shield.