artur_formella
Newbie level 1
Hello!
For the last year a team of young, highly motivated people has built a robot that pours drinks and engineered process of producing such machines.
The requirements for the machine we had from the start:
For a year we worked on mechanics, electronics, software and usability. During that time we made numerous iterations and wrote tons of code. Finally we believe we fulfilled all the requirements.
The project consists of a few aspects:
Mechanics
Frame was designed in Solidworks and is made exclusively from flat laser cut elements 6mm and 10mm in thickness. All parts fit like LEGO blocks and form a rigid and precise 3d structure.
After a lot of experiments we used acrylic glass (PMMA) as the material of choice. Laser cutting source files are at the bottom of the page. Once cut the parts can be assembled using step-by-step manual from **broken link removed**
So how does it work?
Barobot pours drinks by moving carriage with glass under one of 12 bottles.
Each bottle has a dispenser – a common bar optic easily obtainable in bartender shops. Barobot uses both 20ml dispensers for spirits and 50ml dispensers for soft drinks (imperial measurement dispensers are available too). Bottles are set in upside down position in two rows and we let gravity do the work by using a well proven solution.
The dispensers are capable of holding almost any bottle size starting with 0,3l (10 fl. oz) up to party-size Coca-Cola. A wide range of bottleneck sizes fit too. In fact we haven’t seen anything that doesn’t fit except bottles that have plastic insertion in the neck. And those can be easily extracted.
Similarly any glass or even cup will do as long as it fits under the dispenser i.e. is lower than 17cm (6 3/4”). All but the very tallest champaign glasses are fine.
Moving
Glass moves around in two axes – X axis operated by stepper motor and Y by high torque RC model servo. The second “Y axis” is really a curve. We decided that it is easier to create circular than linear motion due to space and cost constraints.
Second servomotor operates “Z axis” which is really just a name for actuator pushing dispenser triggers to pour liquids into glass beneath. It was challenging to find carriage and actuator geometry that would work for both front and back row at the same time. But that is much more cost effective than electro-valve or actuator for each bottle.
Can we shake the drink?
To a degree. Liquids fall into the glass from high enough to mix well. Additionally carriage rapid movements can additionally shake the cocktail. Shaking intensity is limited by center of gravity height and shape of the glass. Such mixing is more than enough for most cocktail amateurs. At the same time we know that there are people who differentiate stirred and shaked mixtures.
Files are ready to laser cut:
Electronics
PCBs use popular components easily obtainable in any major electronics shop.
Main board and carriage board are based on one ATMEGA328 each (the same as Arduino hence Barobot is Arduino compatible in terms of programming). They are responsible for collecting and relaying information from sensors as well as giving commands to actuators (motor and servos).
The other 12 boards are called u-panels with tiny ATmega8 microprocessors. Their main purpose is operating 96 LEDs on top of the robot (for bottle and Barobot interior illumination). Each u-panel board has 4 RGB and 4 white LEDs. Half of them illuminate bottles and the other half robot interior. Each LED is individually controlled using PWM.
All the PCBs communicate via I2C and ISP protocols in a distributed manner. One of the advantages of this setup is that all those independently operated LEDs that can illuminate the frame and individual bottles in a myriad of different ways. It allows for easy extension of the robot by adding another PCB to the bus. Additionally existing boards have spare PINs sockets. These can be used to add extra sensors/peripherals (RFID, range sensor, displays etc.).
High level functions including displaying user interface are performed by Android 7” tablet due to the fact that it is easier to implement “business” logic in Java on Android than in microcontroller’s C++;
Tablet is connected to main board via PL2303 and USB/RS232. Tablet serves as command and control center for all the microchips. Tablet’s WiFi can be used to access Barobot menu remotely via another smartphone or tablet.
While robot works just fine, there is Murphy’s Law plaque hanging in our lab as a friendly reminder. Our main principle is that in the worst case scenario Barobot can fail to pour a drink or it can even pour a wrong drink, but absolutely nothing should ever spill. After all we have have 12 bottles full of liquid hanging upside down within frame.
Barobot utilizes a series of fail-safe detectors:
X and Y axes have closed-loop control systems. There are magnets placed in strategic positions and polarizations to tell the machine about current glass position. Magnets are detected by Hall sensors and Barobot will start pouring only the glass is directly under a bottle.
Each magnet is placed in position that carriage has to reach to successfully pour from a given bottle. This feature allows for automatic calibration of the machine. Here is a graph of magnetic field along X axis.
Notice that outermost magnets are stronger and serve as endswitches.
Glass detection is performed by weight sensor located under glass platform. Again no pouring unless glass weight is detected. This sensor doubles as a pouring detection. If Barobot attempts to pour and glass weight is not changing then something went wrong. Presumably there is no more liquid in the bottle. At the moment weight sensor has only partial support in the code.
Finally Y and Z servos have current sensors. If there is obstacle preventing Barobot to reach desired position and current consumption is high for a prolonged time an error message is produced.
Firmware
Once started all the boards auto-negotiate I2C bus addresses which are later stored in eeproms. Firmware collects data from sensors and relays them to Android. It also receives and interprets commands for LEDs and actuators.
All the commands and communication exchanged between microcontrollers and Android are done asynchronously. So tablet doesn’t have to wait for robot reply/task completion at any moment.
More info about API **broken link removed**
It was important to make all the firmware easily upgradable. Hence ISP bus connecting all the boards. Main board after sending the right command becomes a programmer for other boards (it is compatible with stk500 or Arduino). Additionally mainboard has optiboot bootloader so that it can be programmed itself.
Each non-mainboard PCB can be reseted remotely over I2C. Firmware programming is done by chain-resetting boards along I2C bus. This prevented us from the cable nightmare of star architecture. Programming uses the same PINs as normal work so no additional cables are needed.
So to sum up: a new firmware package can be downloaded on the tablet and then one-click uploaded to all Barobot boards.
Firmware can be modified eg. in standard Arduino IDE application.
Android application
Application was written in standard Eclipse environment. It is divided into a few smaller components to allow for integration with different hardware devices or software packages.
Components:
All the connections between components are defined to be as easy to work with as possible.
Connection Android-PCBs
There is native Android serial port implementation but it hard to use.
Therefor we used library that solves this problem on majority of Android devices
https://github.com/mik3y/usb-serial-for-android
We tried hard to turn any potential pouring problem into programming task. And we succeeded. All the sensors are accessible from user interface.
Application is based on sqlite database. It holds information on cocktail ingredients, drink recipes, LED light-themes etc. We have a plan to allow synchronization of drink recipes between robots.
User first action is to put bottles and define what ingredient is located in which of the 12 slots. Then application filter drink recipes database against available ingredients and shows only cocktails that can be created with current set of bottles.
Of course at any moment user can add his/her own cocktail recipe or pour improvised drink.
Android Application in picture below (merged to one picture due to forum limitation):
Remote ordering
Besides displaying user information tablet doubles as a WWW server. It hosts a web page that allows for browsing menu and ordering drinks from any device like smartphone or another tablet. It is most useful during large parties as many people can browse the menu simultaneously without actually blocking the robot.
LEDs
u-panels: (2x RGB + 2x W) * 12 bottles = 96
carret: 2x RGB + 2x W = 4
mainboard: 2x RGB + 2x W = 4
Total: 108 LEDs
Of course Barobot would work without u-panels and majority of LEDs, but we figured out that illumination adds a lot to robot aesthetics and party atmosphere.
Plans for future
Potential issues when building Barobot on your own
Is such a robot going to take work from bartenders?
No. Bartending and drink creation is both art and liquid pouring. Our robot can only mix cocktail according to a recipe. It won’t talk with you about troublesome day, it won’t tell a joke and you can’t pick it up. Remember Star Trek Enterprise bar? Drinks were produced by replicator but alive bartender was still there. The art of bartending is here to stay.
Open source/Open hardware
Our team performed enormous work to assure that drinks are poured in repetitive and cost effective manner. We used knowledge from a great number of open source projects and consulted numerous experts. Now we are giving it back to the community.
Even if you are not going to build Barobot, pieces of the code like Android-Serial library or distributed I2C ecology might be interesting. All the code is available on Barobot SVN repository.
But we would be very proud if you build your own Barobot based on what we did so far.
Kickstarter campaign
We are producing Barobots as complete kits for DIY assembly. At the moment we are Kickstarting our project. If you like Barobot idea please support us there by getting a robot or one of other gadgets.
Open source/open hardware files
I may only attach up to 10 files per post so if you want to see more photos or download other files please visit our site or repository.
Bill of material (BOM):
**broken link removed**
Source code:
https://code.google.com/p/barobot/source/browse/trunk/#trunk/android/main_app
3D files:
https://code.google.com/p/barobot/source/browse/trunk/#trunk/hardware/design/3d
Kickstarter campaign:
https://www.kickstarter.com/projects/barobot/barobot-a-cocktail-mixing-robot
We hope you will like this project.
For the last year a team of young, highly motivated people has built a robot that pours drinks and engineered process of producing such machines.
The requirements for the machine we had from the start:
- Dosing accurate amounts of ingredients
- Open source/open hardware
- Easy to assemble at home without advanced skills or tools
- As easy as possible to operate by unskilled users (eg. slightly intoxicated late during a party)
- 12 bottle capability
- One load should be enough for ~100 drinks
- Any popular glass and bottle should fit
- Should handle liquors, juices, carbonated liquids, milk and syrups
- No cleaning in between drinks (eg. Pinacolada residues cannot spoil Whiskey and Coke poured next)
- Easy cleaning after the party
- Frame produced in deterministic way made of popular material
- Electronics built of popular parts
- A touchscreen with user interface
- Adjustable user interface touchscreen position
- Intuitive user interface that can suggest drinks
- Illumination of bottles with cocktail ingredients
- LED illumination should add WOW factor to the party
- Upgradeable software and firmware
- Remote cocktail ordering
- Eye-catching design
- One person should be able to move it
- Should fit into 36’’ cabinet or a sedan car
- Can stay in cabinet with alcohol bottles loaded without need for any interaction for long time
- Running on 12V so that it can work from car accumulator
- Easily extendable on software and hardware side
- Easy to resupply ingredients during a party
- And most important: as cost effective as possible
For a year we worked on mechanics, electronics, software and usability. During that time we made numerous iterations and wrote tons of code. Finally we believe we fulfilled all the requirements.
The project consists of a few aspects:
- Hardware,
- Electronics,
- Firmware,
- Android application.
- all the bolts unified to 2 sizes
- all the elements that touch food are certified food-safe
- any amount of liquid can be poured, a fraction of dose is determined by timing of actuator action
- rigid acrylic glass frame that can hold 12 large bottles without flexing
- distributed system of microchips connected by I2C and ISP bus and governed by Android tablet
- stepper motor and servos allow for precision moves with adequate speed
- PCBs are splash proof due to spray coating and location in closed compartments – we had some serious early prototype disasters and electronic components were never harmed
- regulated tablet holder allows for changing angle of view, there is also alternative tablet position at the back of the machine
- timing belt and mechanics hidden from view
- closed-loop positioning system
- automatic calibration
Mechanics
Frame was designed in Solidworks and is made exclusively from flat laser cut elements 6mm and 10mm in thickness. All parts fit like LEGO blocks and form a rigid and precise 3d structure.
After a lot of experiments we used acrylic glass (PMMA) as the material of choice. Laser cutting source files are at the bottom of the page. Once cut the parts can be assembled using step-by-step manual from **broken link removed**
So how does it work?
Barobot pours drinks by moving carriage with glass under one of 12 bottles.
Each bottle has a dispenser – a common bar optic easily obtainable in bartender shops. Barobot uses both 20ml dispensers for spirits and 50ml dispensers for soft drinks (imperial measurement dispensers are available too). Bottles are set in upside down position in two rows and we let gravity do the work by using a well proven solution.
The dispensers are capable of holding almost any bottle size starting with 0,3l (10 fl. oz) up to party-size Coca-Cola. A wide range of bottleneck sizes fit too. In fact we haven’t seen anything that doesn’t fit except bottles that have plastic insertion in the neck. And those can be easily extracted.
Similarly any glass or even cup will do as long as it fits under the dispenser i.e. is lower than 17cm (6 3/4”). All but the very tallest champaign glasses are fine.
Moving
Glass moves around in two axes – X axis operated by stepper motor and Y by high torque RC model servo. The second “Y axis” is really a curve. We decided that it is easier to create circular than linear motion due to space and cost constraints.
Second servomotor operates “Z axis” which is really just a name for actuator pushing dispenser triggers to pour liquids into glass beneath. It was challenging to find carriage and actuator geometry that would work for both front and back row at the same time. But that is much more cost effective than electro-valve or actuator for each bottle.
Can we shake the drink?
To a degree. Liquids fall into the glass from high enough to mix well. Additionally carriage rapid movements can additionally shake the cocktail. Shaking intensity is limited by center of gravity height and shape of the glass. Such mixing is more than enough for most cocktail amateurs. At the same time we know that there are people who differentiate stirred and shaked mixtures.
Files are ready to laser cut:
Electronics
PCBs use popular components easily obtainable in any major electronics shop.
Main board and carriage board are based on one ATMEGA328 each (the same as Arduino hence Barobot is Arduino compatible in terms of programming). They are responsible for collecting and relaying information from sensors as well as giving commands to actuators (motor and servos).
The other 12 boards are called u-panels with tiny ATmega8 microprocessors. Their main purpose is operating 96 LEDs on top of the robot (for bottle and Barobot interior illumination). Each u-panel board has 4 RGB and 4 white LEDs. Half of them illuminate bottles and the other half robot interior. Each LED is individually controlled using PWM.
All the PCBs communicate via I2C and ISP protocols in a distributed manner. One of the advantages of this setup is that all those independently operated LEDs that can illuminate the frame and individual bottles in a myriad of different ways. It allows for easy extension of the robot by adding another PCB to the bus. Additionally existing boards have spare PINs sockets. These can be used to add extra sensors/peripherals (RFID, range sensor, displays etc.).
High level functions including displaying user interface are performed by Android 7” tablet due to the fact that it is easier to implement “business” logic in Java on Android than in microcontroller’s C++;
Tablet is connected to main board via PL2303 and USB/RS232. Tablet serves as command and control center for all the microchips. Tablet’s WiFi can be used to access Barobot menu remotely via another smartphone or tablet.
While robot works just fine, there is Murphy’s Law plaque hanging in our lab as a friendly reminder. Our main principle is that in the worst case scenario Barobot can fail to pour a drink or it can even pour a wrong drink, but absolutely nothing should ever spill. After all we have have 12 bottles full of liquid hanging upside down within frame.
Barobot utilizes a series of fail-safe detectors:
X and Y axes have closed-loop control systems. There are magnets placed in strategic positions and polarizations to tell the machine about current glass position. Magnets are detected by Hall sensors and Barobot will start pouring only the glass is directly under a bottle.
Each magnet is placed in position that carriage has to reach to successfully pour from a given bottle. This feature allows for automatic calibration of the machine. Here is a graph of magnetic field along X axis.
Notice that outermost magnets are stronger and serve as endswitches.
Glass detection is performed by weight sensor located under glass platform. Again no pouring unless glass weight is detected. This sensor doubles as a pouring detection. If Barobot attempts to pour and glass weight is not changing then something went wrong. Presumably there is no more liquid in the bottle. At the moment weight sensor has only partial support in the code.
Finally Y and Z servos have current sensors. If there is obstacle preventing Barobot to reach desired position and current consumption is high for a prolonged time an error message is produced.
Firmware
Once started all the boards auto-negotiate I2C bus addresses which are later stored in eeproms. Firmware collects data from sensors and relays them to Android. It also receives and interprets commands for LEDs and actuators.
All the commands and communication exchanged between microcontrollers and Android are done asynchronously. So tablet doesn’t have to wait for robot reply/task completion at any moment.
More info about API **broken link removed**
It was important to make all the firmware easily upgradable. Hence ISP bus connecting all the boards. Main board after sending the right command becomes a programmer for other boards (it is compatible with stk500 or Arduino). Additionally mainboard has optiboot bootloader so that it can be programmed itself.
Each non-mainboard PCB can be reseted remotely over I2C. Firmware programming is done by chain-resetting boards along I2C bus. This prevented us from the cable nightmare of star architecture. Programming uses the same PINs as normal work so no additional cables are needed.
So to sum up: a new firmware package can be downloaded on the tablet and then one-click uploaded to all Barobot boards.
Firmware can be modified eg. in standard Arduino IDE application.
Android application
Application was written in standard Eclipse environment. It is divided into a few smaller components to allow for integration with different hardware devices or software packages.
Components:
- com.barobot.audio - sound analyzer implementation
- com.barobot.audio.example – standalone example of music light show
- com.barobot.common – config and java interfaces
- com.barobot.hardware.devices – Barobot modules logic
- com.barobot.hardware.serial – low level communication via USB, FTDI, or PL2303.
- com.barobot.isp – programmer lib
- com.barobot.parser – high level communication using synchronized threads and more
- com.barobot.web – sofa server
- main_app – main tablet app android
- main_app_test – unit tests
All the connections between components are defined to be as easy to work with as possible.
Connection Android-PCBs
There is native Android serial port implementation but it hard to use.
Therefor we used library that solves this problem on majority of Android devices
https://github.com/mik3y/usb-serial-for-android
We tried hard to turn any potential pouring problem into programming task. And we succeeded. All the sensors are accessible from user interface.
Application is based on sqlite database. It holds information on cocktail ingredients, drink recipes, LED light-themes etc. We have a plan to allow synchronization of drink recipes between robots.
User first action is to put bottles and define what ingredient is located in which of the 12 slots. Then application filter drink recipes database against available ingredients and shows only cocktails that can be created with current set of bottles.
Of course at any moment user can add his/her own cocktail recipe or pour improvised drink.
Android Application in picture below (merged to one picture due to forum limitation):
Remote ordering
Besides displaying user information tablet doubles as a WWW server. It hosts a web page that allows for browsing menu and ordering drinks from any device like smartphone or another tablet. It is most useful during large parties as many people can browse the menu simultaneously without actually blocking the robot.
LEDs
u-panels: (2x RGB + 2x W) * 12 bottles = 96
carret: 2x RGB + 2x W = 4
mainboard: 2x RGB + 2x W = 4
Total: 108 LEDs
Of course Barobot would work without u-panels and majority of LEDs, but we figured out that illumination adds a lot to robot aesthetics and party atmosphere.
Plans for future
- We want to upgrade design of user interface
- Integration with RFID (eg. a glass with a RFID tag at the bottom would identify user and customize drinks to his/her preferences)
- Implementation of a simple service to synchronize drinks
- Implementation of user friendly light-themes creator for easy, graphical LED programming
Potential issues when building Barobot on your own
- only certain kind of dispensers from UK based company fits at the moment
- PCBs use both sides and require milling
- At least 80W laser is necessary to cut 10mm acrylic glass with enough quality
- Not all the tablets can connect via PL2303
- Cost of around $1800-$2000 for one machine when created individually (if your time is worthless, which is not true)
Is such a robot going to take work from bartenders?
No. Bartending and drink creation is both art and liquid pouring. Our robot can only mix cocktail according to a recipe. It won’t talk with you about troublesome day, it won’t tell a joke and you can’t pick it up. Remember Star Trek Enterprise bar? Drinks were produced by replicator but alive bartender was still there. The art of bartending is here to stay.
Open source/Open hardware
Our team performed enormous work to assure that drinks are poured in repetitive and cost effective manner. We used knowledge from a great number of open source projects and consulted numerous experts. Now we are giving it back to the community.
Even if you are not going to build Barobot, pieces of the code like Android-Serial library or distributed I2C ecology might be interesting. All the code is available on Barobot SVN repository.
But we would be very proud if you build your own Barobot based on what we did so far.
Kickstarter campaign
We are producing Barobots as complete kits for DIY assembly. At the moment we are Kickstarting our project. If you like Barobot idea please support us there by getting a robot or one of other gadgets.
Open source/open hardware files
I may only attach up to 10 files per post so if you want to see more photos or download other files please visit our site or repository.
Bill of material (BOM):
**broken link removed**
Source code:
https://code.google.com/p/barobot/source/browse/trunk/#trunk/android/main_app
3D files:
https://code.google.com/p/barobot/source/browse/trunk/#trunk/hardware/design/3d
Kickstarter campaign:
https://www.kickstarter.com/projects/barobot/barobot-a-cocktail-mixing-robot
We hope you will like this project.